HK1195022A - Dispensing systems - Google Patents

Description

Dispensing system

Technical Field

The present invention relates generally to dispensing systems and more particularly to applicators for applying pharmaceutical formulations to the scalp and scalp margins and to 5 other body areas, particularly for applying pharmaceutical gels to psoriasis patients. More particularly, the present invention relates to dispensing systems and applicators for use with medicament cartridges, and to cartridges for use with dispensing systems and applicators.

Background

Psoriasis develops when the usual circulation of replacement skin cells accelerates. Although psoriasis manifests itself as a skin disorder, it has been established in recent years that the origin lies in the immune system. Usually the skin cells themselves are replaced for about 21 to 28 days, but the replacement of skin cells in psoriasis patients is rapid, possibly every 2 to 6 days. This acceleration results in the accumulation of skin cells on the skin surface, commonly referred to as psoriatic plaques.

Psoriasis patches or plaques may occur in substantially any location of the body, but most commonly occur on the elbows, knees, lower back and scalp. Typically, a psoriasis patch appears as a raised patch with a silvery white scurf covering the outside of the red skin. Dandruff is a 20-fold accumulation of skin cells waiting to shed and produces red lumps due to the increased number of blood vessels necessary to support the increased volume produced by the cells.

Plaques are often itchy and uncomfortable, and even painful or sore, and a range of treatments are available to alleviate the condition. Treatment regimens include topical therapy, photoelectric therapy, systemic drugs, and bio-injections. Treatment is selected according to the severity of the condition, but in most cases topical therapy is preferred, at least at the very beginning of the episode, because of the lower risk of such therapy and the greater convenience to the patient.

For many psoriasis patients, topical treatment (that is, application of the formulation directly to the skin) is sufficient to keep the condition under control. Conventional formulations include formulations based on one or more of vitamin D, coal tar, dithranol, vitamin a and steroids, and these formulations are supplied in the form of semi-solid formulations.

Typically, medical personnel also prescribe a dosage regimen that defines the amount of medicament to be applied and the frequency of application at the time of such a formulation. Generally, the medicament is supplied in a tube from which an amount 5 can be expressed for application to the skin area to be treated. Typically, the amount to be applied is defined in finger-tip units (FTUs), one finger-tip unit being the distance from the tip of an adult finger to the first fold of that finger, and the number of FTUs to be applied depends on the area of application, so the dose is determined according to the area of skin to be treated.

The multiple psoriasis patients who represent applicants' interviews indicate that reliable dosing is a serious problem. FTU is an inaccurate measurement because of the large interpersonal variability. If only a small area of skin is infected, it may be necessary to use a sub-FTU, which is also difficult to measure. Obviously, if insufficient medicament is applied, the affected skin will not relieve or heal to the same extent as at the correct dosage. On the other hand, if the applied medicament exceeds and is greater than the prescribed dose, more serious consequences may occur. For example, topical treatments are overdosed, which can lead to severe irritation and burning. Formulations such as steroid creams, if administered in excess, may result in absorption through the skin and cause deleterious side effects such as may be experienced in systemic dispensing of steroids.

One common side effect of conventional steroid use is thinning and weakening of the skin. Even if the steroid cream is applied to the psoriatic area at the correct FTU dosage, the skin of the user's fingertips is often weakened by rubbing in the cream. It is recommended to apply the steroid medication with gloves to avoid this problem, but the user feels that it is too cumbersome, cumbersome and impractical to do so.

For patients with psoriatic arthritis, the act of squeezing the vial or tube may be difficult and/or painful, making it more difficult to dispense a controlled dose.

More complications may occur when the area of skin to be treated includes the scalp or scalp regions (e.g., forehead, neck, and behind the ears). Hereinafter, reference to the scalp includes the scalp region. Self-administration can present a problem because the area being treated is not readily visible without assistance, so it may be necessary to apply the drug "blindly" to the back of the scalp. Treatment of the scalp is further complicated by the need to separate the hair to expose the affected area, and even then, many of the drugs will eventually inevitably spread onto the hair rather than the scalp, and the effective dose will be reduced.

Disclosure of Invention

Thus, applicants have recognized that there is a need for a medicament applicator for applying a semi-solid formulation, such as a psoriasis paste or gel, to an area of the body containing the scalp that overcomes, or at least alleviates, one or more of the aforementioned problems.

The term medicament or formulation as used herein is intended to encompass pharmaceutical creams, gels, ointments and the like, which may be poured or squeezed out and spread for topical application. These terms are used interchangeably throughout and thus when referring to ointments, gels, etc., should be understood to encompass other forms of semi-solid formulations. Of course, while the applicator and dispensing system described hereinafter is specifically intended for the delivery of pharmaceutical agents, it may also be used for the delivery of non-pharmaceutical agents, and such use is encompassed by the statement and description of the preferred embodiments of the invention. Viewed from a first aspect, the present invention resides in a hand-held applicator for self-administration of a semi-solid medicament directly to the scalp, said applicator comprising:

an applicator head comprising one or more elongate dispensing nozzles for passing through hair and contacting the scalp in the area to be treated;

an applicator body for receiving a medicament reservoir;

a pump assembly comprising at least one pump chamber having one inlet for receiving medicament from the medicament reservoir and one or more outlets for discharging medicament to the or each dispensing nozzle on the applicator head; and

an actuator operable on the or each pump chamber for pumping a dose of medicament in the chamber through the or each outlet and dispensing a respective dose of medicament from one or more of the dispensing nozzles onto the scalp,

wherein the applicator head and applicator body are fixed relative to one another in use so that movement of the nozzle away from the scalp or other body area during actuation can be avoided.

It will be appreciated that by fixing the applicator head and body relative to each other, the user may for example first position the nozzle on the scalp in the area to be treated and then deliver a dose of medicament to that area, the nozzle not moving away from the scalp on operation of the actuator. In this way, the user can confidently deliver the dose of the medicament to the scalp rather than to the hair. Once the dose has been expelled onto the scalp, the user may then use the nozzle to disperse the medicament in the vicinity. Thus, the medicament can be delivered and applied without lifting the nozzle from the scalp.

Viewed from another aspect, the invention resides in a hand-held applicator for self-administration of a semi-solid medicament directly to the scalp, said applicator comprising:

an applicator head comprising one or more elongate dispensing nozzles for passing through hair and contacting the scalp in the area to be treated;

an applicator body for receiving a medicament reservoir;

a pump assembly comprising at least one pump chamber having one inlet for receiving medicament from the medicament reservoir and one or more outlets for discharging medicament to the or each dispensing nozzle on the applicator head; and

an actuator operable on the or each pump chamber for pumping a dose of medicament in the chamber through the or each outlet and dispensing a respective dose of medicament from one or more of the dispensing nozzles onto the scalp,

wherein the applicator head is replaceable on the applicator body, enabling the applicator to be changed from a single nozzle applicator to a multi-nozzle applicator and vice versa.

The applicator according to this further aspect may thus be adapted by the user or supplier to suit the severity of the condition being treated. Preferably, the applicator head and the applicator body are fixed relative to each other in use so that movement of the nozzle away from the scalp during actuation can be avoided.

Viewed from a further aspect the present invention consists in a hand-held applicator for self-administration of a semi-solid medicament directly to the scalp, said applicator comprising:

an applicator head comprising a plurality of elongate dispensing nozzles for passing through hair and contacting the scalp in an area to be treated;

an applicator body for receiving a medicament reservoir;

a pump assembly comprising at least one pump chamber having one inlet for receiving medicament from the medicament reservoir and one or more outlets for discharging medicament to each dispensing nozzle on the applicator head;

an actuator operable on the or each pump chamber for pumping a predetermined dose of medicament from the chamber through the or each outlet and dispensing a respective dose of medicament from one or more of the dispensing nozzles onto the scalp; and a nozzle selector mechanism adapted to permit dispensing of medicament from all nozzles when in a first selected mode, and permit dispensing of medicament from only a single nozzle when in a second selected mode.

The applicator according to this aspect provides ultimate versatility in that the user can choose whether to dispense from only a single nozzle (suitable for application in smaller or poorly treated areas), or from all nozzles (suitable for the case of larger areas and more easily accessible areas to be treated), and whether it is necessary to dispense a single dose from one nozzle or multiple single doses through all nozzles. Also, the applicator head and the applicator body are fixed relative to each other in use so that movement of the nozzle away from the scalp during actuation can be avoided.

It will of course be appreciated that patients may often have psoriatic plaques on multiple areas of the body, including on the scalp and elsewhere. In the past, treatments have included applying one pharmaceutical formulation to the scalp and a different formulation to other body areas, for example, applying a gel formulation to the scalp and a more viscous paste formulation to other skin areas. However, this adds a greater degree of inconvenience to users who need to use a single formulation regardless of the area.

Thus, and viewed from a further aspect, the invention resides in a hand-held applicator for targeted self-administration of a semi-solid medicament directly to the scalp and other body areas, said applicator comprising:

an applicator head comprising an elongate dispensing nozzle capable of passing through hair for contacting the scalp;

an applicator body for receiving a medicament reservoir;

a pump assembly comprising a pump chamber having an inlet for receiving medicament from the medicament reservoir and an outlet for discharging medicament to the dispensing nozzle on the applicator head; and

an actuator operable on the pump chamber for pumping a dose of medicament in the chamber through the outlet and dispensing a corresponding dose of medicament from the dispensing nozzle onto the scalp or other body area,

wherein the applicator head further comprises an application face for spreading the delivered medicament over the body area to be treated.

The applicator according to this further aspect is particularly suitable for use by a patient as both a scalp applicator and a body applicator. In particular, the nozzle is capable of penetrating the hair, thereby allowing the medicament to be delivered directly to the scalp, and the nozzle may then also assist in spreading the medicament on the scalp in the same vicinity. Also, the nozzle can deliver the medicament directly to another body area, for example on an arm or leg, whereupon the applicator surface can be used to spread the medicament over the desired body area. Thus, the applicator may be used universally by all psoriasis patients, whether the plaque area is large or small, whether it is for physical use or for scalp use. Furthermore, where the medicament loaded into the reservoir is suitable for use on both the scalp and body, the patient can apply the medicament to all infected areas using the same applicator, thereby eliminating the need to use separate applicators for the scalp and body.

Also, the applicator head and the applicator body are preferably fixed relative to each other in use so that movement of the nozzle away from the scalp or skin during actuation can be avoided.

It will be appreciated that applicators according to all aspects of the invention as described herein may incorporate such an application face, thereby making those applicators also particularly suitable for use in applying medicaments to areas of the body other than the scalp.

Various preferred features of the applicator according to any or all of the above aspects are described below. It will be understood that the features described apply generally to all of the foregoing aspects of the invention, unless otherwise stated, and to the dispensing systems described more generally below.

The applicator according to the present invention desirably comprises an airless delivery system whereby the medicament is substantially free of air contact while within the applicator. Providing an airless system not only protects the medicament from oxidation and hence deterioration due to exposure to air, but also ensures reliable delivery of precise doses to the scalp or other body area. In addition, using an airless system, the applicator may be held in any orientation while dispensing the medicament. In other words, during application of the medicament, the applicator body may be held in a substantially vertical orientation, or inverted, or in any orientation in between, thus helping the user to apply more easily.

To help ensure that the medicament store is stored and maintained in an airtight manner prior to use, the medicament is preferably supplied in a cartridge. Thus, the applicator preferably comprises a cartridge port for receiving the dispensing end of a cartridge containing medicament, said port being in fluid communication with the or each inlet of the respective pump chamber of the pump assembly. The cartridge port is most conveniently provided on the applicator head. The cartridge port is preferably adapted to engage with the cartridge and seal around the cartridge outlet, for example by means of an interference (push) fit, screw fit or bayonet fit, whereby leakage of medicament between the cartridge and the cartridge port can be avoided once the cartridge has been fully assembled. The cartridge port may include a seal for sealing the dispensing end of the cartridge, for example, against an outer wall of the cartridge, for example around a neck or nozzle portion thereof, or against an inner wall thereof, for example, within the neck portion, or both. A simple form of seal may comprise an O-ring seal on the applicator or a preferably arranged cartridge port may comprise a stopper which seals against the inner wall of the dispensing end of the cartridge (preferably the neck portion). In the latter case, the stopper preferably comprises a central bore for permitting the flow of medicament from the cartridge to the pump chamber via the inlet. More preferably, the inlet of the pump chamber is integral with the stopper.

Typically, the cartridge will be provided with a cartridge cover, typically a plastic cover, which can be removed prior to fitting the cartridge to the applicator. In order to reduce the risk of damage to the nozzle or neck of the cartridge in the event of a cartridge being dropped, the cartridge cover is preferably reinforced, for example, in the form of a double wall, most preferably in the form of an H-section. This ensures that if dropped, the outer wall of the H section will absorb at least some of the energy by virtue of the plastic deforming rather than having the energy transmitted to the nozzle, which could otherwise result in the nozzle breaking or cracking. Alternatively, instead of or in addition to the cap, the cartridge may be provided with a seal, for example a foil seal, at its dispensing end at its outlet, which foil seal may be removed prior to assembly or may be pierced by the applicator when the cartridge is assembled thereto.

The cartridge may comprise a collapsible container, for example a pouch, typically a foil-lined bag, which is preferably supplied within a rigid casing (so-called "bag-in-bottle" technology), but more preferably the cartridge comprises a substantially rigid container, for example a tube. Most preferably, the cartridge comprises a tube with a plunger inside, which is in sealing contact with the inner tube wall, e.g. with a pair of lip seals or other such resilient seal(s) which is/are drawn upwards towards the outlet when the medicament is expelled. The plunger maintains an air-free environment for the medicament within the cartridge.

In one arrangement, the cartridge may be integral with the applicator body, and the applicator body may thus consist essentially of the cartridge. Alternatively, the cartridge may be separate from but at least partially contained within the applicator body. In either case, once the cartridge has been exhausted, it can simply be removed and extracted from the cartridge port and a new cartridge inserted. Thus, the applicator head, pump assembly and applicator body (where applicable) can be reused many times. In another alternative arrangement, the applicator may be entirely disposable, with the applicator head, pump assembly and actuator being discarded with the cartridge once the cartridge is exhausted. In the latter case, the cartridge may include a one-way locking feature to prevent reuse.

In a particularly preferred arrangement, the applicator head, the pump assembly and the actuator are provided as a unit, hereby also referred to as a head assembly, and the applicator body consists essentially of a medicament cartridge adapted to fit together with the applicator head. Thus, by attaching the assembled cartridge to the head assembly, the applicator is assembled ready for use. More preferably, the head assembly and the cartridge are each provided with complementary interlocking or one-way features for preventing the cartridge from separating from the head assembly once the cartridge has been assembled. For example, the dispensing end of the cartridge may be provided with an inwardly directed flange and the cartridge port on the applicator head may be provided with a lip seal, for example on a stopper inserted into the neck of the cartridge. It will be appreciated that once the lip seal has advanced beyond the return flange of the cartridge neck, it is no longer possible to separate the cartridge from the applicator head without breaking the seal or breaking the flange. Alternatively, the stopper may be provided with an annular groove for interlocking with an annular projection on the inner wall of the cartridge neck. Thus, once the stopper has been fully inserted into the bobbin neck, the projection is retained in the groove and it is likewise difficult to pry the applicator head from the bobbin without breaking the connection.

In a further alternative "one-time only" assembly arrangement, the cartridge and head assembly may include complementary threads, whereby the cartridge may be screwed onto the head assembly, and a plurality of spaced ribs are provided around the cartridge neck, and one or more, preferably two, flexible tabs are provided on the cartridge port, whereby the ribs are able to press down on the tabs and against the tabs when the cartridge is screwed onto the head assembly, but are unable to press down on the tabs in the reverse direction, thereby preventing the cartridge from separating (screwing off) from the head assembly.

On the other hand, where the applicator is intended for re-use and the applicator body is separate from the cartridge, the body may comprise a hollow container, typically a cylinder, open at the distal end (the end furthest from the pump assembly) to allow insertion of the cartridge. Advantageously, the length of the cylinder is such that when inserted in the cylinder and fitted to the cartridge port the end of the cartridge extends beyond the distal end of the cylinder, thus permitting the cartridge to be secured to the cartridge port whilst still being gripped, for example by press-fitting or screwing. To allow the user to check whether the medicament is fitted to the applicator, the distal end of the cartridge may carry a visual indication of its contents.

In one arrangement, the length of the cartridge, when assembled, extends beyond the end of the applicator body so that a user grips the exposed length of the cartridge during application of the medicament. Alternatively, the cartridge may be substantially enclosed within the applicator body. An end cap may be provided on the cartridge, supplied at its distal end or as an integral part of the applicator, for closing the open end of the applicator body with the cartridge retained therein. The end cap may also be used to hold the cartridge in place relative to a cartridge port that leads directly or indirectly to the fluid inlet of the pump assembly. The end face of the non-dispensing end of the cartridge or end cap of the applicator body is preferably flattened or otherwise contoured as appropriate to support the applicator in a substantially vertical position with the nozzle uppermost for storage.

It will be appreciated that the applicator must first be primed, so that the pump chamber and the dispensing nozzle or nozzles are filled with medicament, before an initial dose of medicament is delivered. The priming operation may be automatic or manual, for example manual priming may be performed by operating the actuator to pump medicament from the applicator body into the pump chamber and out through the or each nozzle; once the medicament begins to emerge from the or each nozzle, the applicator is fully primed and ready for use. Any medicament expelled from the nozzle during priming can be wiped off so that the next operation of the actuator will dispense an accurate known volume (i.e. dose) of medicament. The dispensed dose typically comprises medicament from a nozzle and the volume of the dose dispensed corresponds to the volume of medicament displaced from the or each pump chamber.

Inevitably, due to filling and production tolerances, the filling level of the medicament in the cartridge may vary to such an extent that it cannot be filled by operating the actuator alone. For example, even if only 0.5cm3 of air is evacuated from the cartridge neck itself, this may require approximately 30 puffs of the actuator to displace air from the cartridge neck and from the nozzle of the pump chamber and head assembly before the medicament emerges from the nozzle tip.

Thus, as an alternative to priming by operation of the actuator alone, or in order to reduce the number of aspirations necessary for the actuator in a priming operation, the cartridge and the applicator head, or at least the cartridge port thereof, may be configured in such a way as to draw some or all of the air when the cartridge is fitted to the head. For example, as described above, the cartridge port may include a detent for fitting into the neck of the cartridge, wherein the detent is provided with a vent through which air displaced by the detent is forced when pushed into the neck of the cartridge. Displacing the air, the stopper has a central bore through which medicament from the cartridge is permitted to flow to the pump chamber. The stopper bore may thus provide a pump inlet to the pump chamber. Preferably, the stopper bore has a first portion of a first diameter and a second portion of a second diameter greater than the first diameter, and a bridging portion between the first portion and the second portion forming a valve seat of an inlet valve of the pump chamber. The bridge portion most preferably comprises an inverted frusto-conical surface which acts as a valve seat for, for example, a spherical or semi-spherical valve, particularly a ball valve or the like.

The stopper preferably has a length sufficient to displace some or all of the air that may be present in the cartridge first (typically above the fill level at the dispensing tip) as the stopper is advanced into the neck of the cartridge.

To facilitate insertion and form an effective seal with the neck of the cartridge, the stopper may be provided with a lip seal around its outer face. The lip seal forms a continuous seal with the bobbin neck but requires less insertion pressure than the entire outer face itself would require to provide a seal.

In one arrangement, the side wall of the stopper may be provided with a thread-like channel, for example in the form of a helical lip seal, in fluid communication with the stopper bore to permit air to escape as the stopper is advanced into the cartridge. Because the medicament is not easily forced through a threaded channel, a large amount of back pressure builds up inside the cartridge when the front end of the stopper reaches the medicament and begins to displace the medicament. This back pressure can be used to push the plunger back at the opposite end of the cartridge (if provided), thereby largely avoiding any spillage of the medicament during filling. The cartridge therefore preferably has the capacity to accommodate this reverse movement of the plunger (which may occur during filling of the applicator).

Although the stopper may comprise a substantially solid member, the stopper may alternatively comprise a substantially hollow member. For example, the stopper may comprise concentric inner and outer cylindrical walls, engaged at the insertion end to prevent ingress of medicament except through a central bore formed through the inner cylindrical wall providing a passage for medicament to be dispensed from the cartridge. The outer cylindrical wall preferably seals against the end face of the bobbin neck when the bobbin is in its fully inserted position, for example by means of an outwardly directed flange at its end or a lip seal around the outer circumference adjacent the end. The hollow retainer may include a compressible material to enhance the quality of the seal. Whether the stopper is of solid or hollow construction, the diameter of the outer or outer wall may be narrowed towards the insertion end to provide a taper to facilitate entry into the bobbin neck.

The cartridge port may comprise a cap member which cooperates with an outer wall of the cartridge neck, for example by interlocking, to retain the cartridge in sealing engagement with the applicator head. For example, the cap member may have internal threads that engage external threads on the neck of the cartridge. The cover member has an aperture for allowing the medicament to flow into the pump chamber.

In one arrangement, the cartridge port may include a detent attached to the cap member such that the detent is advanced internally and the cap is advanced externally of the cartridge neck. Preferably, when the stopper is provided with an outwardly directed flange, the cartridge is fitted to the cartridge port by: the applicator head or head assembly is first pushed onto the cartridge, the cartridge is then screwed to secure and fasten the connection, the screwing action also serving to compress the flange between the upper edge face of the cartridge neck and the cap member, thereby sealing the cartridge from the head assembly so that the medicament can only be expelled through the central bore. As discussed above, any backpressure created during cartridge engagement can be relieved by reverse movement of the cartridge plunger.

In another arrangement, the neck of the cartridge may be double walled, the walls being sufficiently spaced apart to form a chamber therebetween for containing any spillage of medicament and air drawn out as the stopper is advanced into the neck of the cartridge. In this way, any medicament displaced during priming is retained in the chamber between the neck walls and is prevented from leaking from the applicator. In this arrangement, as an alternative to a separate cap member, the stopper may further comprise a cap portion which provides a seal with the outer neck wall. In addition, the cap portion may also form a seal with the inner neck wall so that medicament in the cartridge does not come into contact with any air remaining in the neck chamber and any medicament that has spilled into the neck chamber cannot be passed back to the cartridge. For example, the cap portion preferably has two concentric walls depending from its inner end face, said walls extending such that these walls seal against the inner and outer neck walls respectively only when the stopper has been pushed almost to its full extent. In this way, a seal is formed after the air has been almost completely evacuated by the stopper and then by the medicament-induced displacement as the stopper advances.

A further alternative arrangement for a filling applicator may be in the configuration of a cartridge cover which seals the cartridge during storage and which is removed from the cartridge prior to assembly of the cartridge to the applicator head. In particular, the cartridge cap may include a refill insert for the non-dispensing tip of the cartridge, whereby after removal of the cap from the dispensing tip, the refill insert is inserted into the non-dispensing tip to advance the cartridge plunger from behind. In this way, the cartridge cap acts as a tool to drive the plunger and thereby draw air through the applicator head. The cartridge cap may also be used in this manner in conjunction with the other filling arrangements described above. Although the cartridge cap/filler insert may remain in the rear end of the middle cartridge after filling, it is preferred to remove and discard the cartridge cap/filler insert. In this way, a user of the applicator can view the plunger position by looking into the non-dispensing end of the cartridge and thereby measuring the degree of consumption of the cartridge.

The filling insert may comprise an outer wall comprising a first portion having a circumference substantially the same as the outer circumference of the main cartridge body and a second portion having a circumference smaller than the outer circumference to allow insertion into the non-dispensing end of the cartridge body for advancing the plunger. The second part preferably has a circumference which permits sliding along the inner cartridge wall and a length sufficient to advance the plunger to complete filling before the first part abuts the cartridge end, thus further preventing insertion. The filling insert preferably includes a threaded portion or the like for engaging a complementary engagement feature on the neck of the cartridge and serving as a cap to secure the insert to the neck portion. Furthermore, the cartridge cover or insert desirably has a recessed portion which, when fitted onto the cartridge neck, extends into the cartridge neck, the recessed portion occupying a substantial amount of the neck portion, thereby limiting the volume of air present in the cartridge at the neck portion when the cover is in place. In this way, the medicament within the cartridge is not exposed to large amounts of air, which may adversely affect the quality of the medicament.

Turning to the dispensing nozzles of the applicator, these nozzles preferably project at an oblique angle to the applicator body, and in the case where more than one nozzle is provided, the nozzles preferably extend parallel to each other. By tilting the nozzle relative to the applicator body, the user does not have to reach areas of the scalp that are not conveniently accessible (e.g. behind the head), the applicator is more comfortable to hold (especially against the scalp), and the nozzle can be gently placed against the skin when used to dispense medicament to an area of the body. The nozzle tip may protrude beyond the outer circumference of the applicator body.

In one arrangement, the nozzle may project substantially perpendicularly from the inclined face of the applicator head. This arrangement is not only advantageous in helping to reduce stress (especially when two or more nozzles are used to massage the medicament on the scalp), but also allows for a more direct, unrestricted flow path for the medicament.

As mentioned above, the applicator may comprise an applicator face for spreading the dispensed medicament over an area of the body other than the scalp. In this arrangement, the applicator face is preferably disposed adjacent the dispensing nozzle, preferably adjacent a single nozzle. More preferably, the dispensing nozzle is continuous with the application face, rather than projecting from a portion of the applicator head separate from the application face.

To facilitate diffusion of the medicament, the application surface is preferably substantially planar or slightly convex. Furthermore, to avoid scratching the user's skin when spreading the medicament, the outer edge or perimeter of the application face is preferably circular. Most preferably, the application surface is substantially circular or oval.

The application face may be inclined relative to the applicator body so that a user can deliver medicament from the nozzle to the body and use the application face to spread the medicament simply by adjusting the orientation of the applicator relative to the body, that is, without requiring relative movement between the applicator and the user's hand. Thus, the user does not need to modify his grip on the applicator to achieve the dispensing and subsequent spreading of the medicament on the user's scalp or skin.

In one preferred arrangement, the application face (which is generally planar or slightly convex) may comprise a tapered portion which comprises a portion of the nozzle. In other words, a portion of the outer surface of the nozzle comprises an extension of the application surface, preferably the application surface and the nozzle together present a substantially tear-drop shaped face, the apex comprising the nozzle. When the applicator is erected on the tip (that is to say the non-dispensing tip of the cartridge or the end cap of the applicator body acts as the base), the application face and nozzle together preferably constitute an upwardly facing sloping surface of the applicator.

Other ergonomic arrangements of the applicator face and nozzle are also contemplated, such as providing a side-facing application face, that is to say an application face lying substantially parallel to the longitudinal axis of the applicator body. In this orientation, the nozzle may still be substantially continuous with the application face and extend at an oblique angle relative to the longitudinal axis. Alternatively, the applicator comprises a pair of opposed, side-facing application faces, wherein the nozzle extends from and is substantially continuous with both faces; this arrangement is particularly versatile and easy to use for both left-handed and right-handed people.

In another alternative arrangement, the application surface may be provided substantially below the nozzle. For example, a generally upwardly inclined nozzle is suspended above the application face when standing on its base (such as provided by an end cap on the applicator body or the non-dispensing end of a cartridge). In this arrangement the application surface is preferably also inclined upwardly, but in the opposite direction to the nozzle.

The cross-section of the bore of the nozzle through which the medicament is forced after dispensing may be substantially uniform or have a portion which narrows towards the nozzle tip. The drilling of the nozzle may in fact be provided by a tubular member or an insert within the nozzle. To achieve strength and ease of cleaning, the nozzle may flare outwardly at its base (i.e., at the boundary between the nozzle and the applicator/application face), but otherwise have a generally uniform cross-section along a substantial length of its stem. More preferably, however, the outer profile of the or each nozzle is tapered such that the nozzle cross-section decreases progressively along its length towards the nozzle tip. This tapered nozzle has even better mechanical strength and also provides a smoother, cleanable surface.

The external nozzle profile may be generally cylindrical or conical, with the nozzle tapering towards its tip, but may likewise be flat in one or more planes, typically as the nozzle extends from and is substantially continuous with the application face. It is desirable that the outer profile of the nozzle, as with the application face, contain only smooth rounded edges to avoid discomfort to the skin or scalp during application of the medicament. Conveniently, the nozzle, or at least a substantial portion thereof, may be integrally moulded with the applicator head.

When the nozzle extends from the applicator face, the applicator face is preferably inclined at an angle in the range 45 ° to 65 °, more preferably 50 ° to 55 °, and especially 52 ° relative to the longitudinal axis of the applicator body. Alternatively, when the applicator comprises an application face for spreading the medicament, the application face may be substantially parallel to the longitudinal axis of the applicator body, or substantially perpendicular to said axis, or at any angle therebetween, typically in the range 20 ° to 60 °. The applicator head may be offset relative to the applicator body when parallel to the longitudinal axis.

When there are more than two nozzles (such as in an applicator intended primarily for use on the scalp), it is necessary that the tips of all the nozzles terminate in the same plane, thereby ensuring that all the nozzles can rest against the scalp at the same time. This is important to avoid the medicament being dispensed into the hair and to keep all the nozzles against the scalp during the treatment of spreading the medicament over the desired area. In this regard, three nozzles are particularly preferred, as these three nozzles will remain stable over the surface at all times. In such scalp applicators in which the nozzles project from the applicator face, the applicant has found that a nozzle angle (that is to say the angle between the longitudinal axis of the or each nozzle and the longitudinal axis of the applicator body) of between about 30 ° and 40 ° is suitable, more preferably about 35 °.

It will be appreciated that when the nozzles extend from the applicator face (either a single nozzle or a plurality of nozzles of equal length all together), the applicator face will preferably be inclined at the same angle as the nozzle angle. However, if the nozzles are not all of equal length, the applicator face is preferably inclined at an angle narrower than the nozzle angle. For example, the angle between the plane of the applicator face and a plane substantially perpendicular to the longitudinal axis of the applicator body (hereinafter referred to as the face angle) may be between about 30 ° and 60 °, more preferably about 45 °.

In any event, to ensure that the nozzles effectively penetrate the majority of the thickness of the hair, the minimum length of each nozzle is preferably 10mm, more preferably more than 15mm, and most preferably 18mm or more. Although the length of the nozzle can be increased significantly, at least in theory, any nozzle beyond about 30mm is susceptible to damage and is therefore not recommended.

When there are two or more nozzles, the nozzles are preferably spaced apart by at least 20mm and less than 40 mm. More preferably about 25mm to 35mm, especially 27mm to 33mm, the lower end of the range provides a desirable diffusion pattern (more uniform scalp coverage) and the upper end of the range provides good handling stability during massaging.

To treat the scalp, once the agent has been dispensed from the nozzle, the nozzle is typically "massaged" against the infected scalp or used in a similar manner to spread the dispensed agent over a smaller body area (e.g., over a smaller plaque). For this reason, the or each nozzle preferably has a tip of softer or more resilient material relative to the material used for the main elongate portion of the nozzle, which should be relatively rigid. For example, the nozzle tip may include an elastomeric pad or the like for permitting the gradual diffusion of the medicament over sensitive areas of the scalp. Providing a soft, resilient nozzle tip is beneficial to the comfort of the user even when using the applicator to treat other body areas.

The material selected for the nozzle tip may affect the balance between feel (softness against the scalp or skin) and penetration (separation of hair). For example, a rubber tip may provide better comfort than a polymer tip, but less penetration. In addition, the manner in which the tip is secured to the nozzle stem may also affect the feel of the tip to the user and the ability of the tip to penetrate. Examples of different ways of securing the nozzle tip to the nozzle stem include using outheaded bolts, internal rivets, and by stretching the tip over the nozzle stem.

To avoid the nozzle being blocked by the scalp or skin when discharging, or by loose patches, for example due to massaging the nozzle tip against the scalp, the discharge outlet may be located laterally on the nozzle, rather than having a terminal port/opening. In this way, with the nozzle resting against the scalp, the medicament can still be expelled directly onto the scalp, or onto the skin in other body areas, but from one or more side ports. In a preferred arrangement, the or each nozzle comprises a nozzle stem having an end port and a nozzle tip (in the form of an end cap), overlying the end port, and having opposed side ports through which medicament emerging from the end port is directed.

To help avoid any foreign material entering the applicator through the nozzle, the or each nozzle may be terminated in an outlet valve (e.g. a pin valve or a slit valve) which opens under positive pressure on the medicament in the pump chamber to allow the medicament to be expelled through the or each nozzle.

Of course, it is desirable to protect the applicator head, in particular the nozzle, when the applicator is not in use, and in this regard, the applicator may further comprise a lid or closure for closing the applicator head. Preferably, the protective cover fits over and is retained on the applicator head, for example by complementary engaging features on the cover and the applicator head or applicator body, for example by a snap-fit mechanism or screw cap or simply by a friction fit. After the applicator has delivered a dose of medicament to the scalp and the nozzle has massaged in the medicament on the desired area, the applicator head (containing the nozzle) may be wiped clean and the protective cover replaced.

Advantageously, the cap of the applicator head not only conceals the application face, but also serves to seal the nozzle tip. Where the applicator head comprises a single nozzle continuous with the applicator face, the hood may be shaped to enclose the nozzle and the applicator face. More preferably, the applicator cover also extends to shield the actuator pull rod from accidental actuation. This cover may thus extend to cover substantially the entire applicator head and actuator or head assembly. By also shielding the actuator pull rod, inadvertent damage to the actuator when the applicator is not in use can also be avoided. The cover not only simply shields the actuator pull rod from accidental use, but may also extend to completely enclose the pull rod.

In yet another alternative arrangement, the applicator cover does not extend to obscure the actuator, but may instead contain an actuator lock for preventing actuation. For example, the cover may include at least one locking member for insertion behind the actuator, such as under its pull rod arm, to prevent movement of the actuator. Preferably, the hood actuator lock comprises a pair of arms which may be clipped under opposite sides of the actuator pull rod, more preferably each arm terminating in a projection (e.g. a wedge-shaped projection) so as to substantially inhibit any movement of the actuator pull rod towards the applicator body or cartridge. It is desirable that the arms of the applicator cover lock be sufficiently resilient to permit the arms to spread apart during mating and to allow the arms to spring back behind the actuator pull rod once released.

When the applicator is fully assembled for use, the pump assembly of the applicator is preferably enclosed, for example contained within the body of the applicator or more preferably within the head of the applicator, particularly as a component of the head assembly, or therebetween, thereby ensuring that the components of the pump can remain clean and hygienic. Both the applicator head (including the nozzle and the application face (where provided)) and the applicator body are preferably contoured in such a way as to provide a substantially continuous outer surface so that the applicator as a whole can be easily cleaned by wiping.

Advantageously, the or each fluid inlet of the pump assembly has an inlet valve for sealing the inlet against the medicament reservoir (e.g. against the cartridge) under positive pressure in the pump chamber and opening the fluid inlet under negative pressure in the pump chamber. Thus, the or each inlet valve is closed when the actuator exerts a positive pressure on the medicament in the pump chamber to effect expulsion, but is opened when the pump chamber has been evacuated and the actuator is released. It will be appreciated that a negative pressure is created in the pump chamber immediately after expelling a dose of medicament from the pump chamber and simultaneously opening the inlet valve, so that another dose of medicament is drawn out of the medicament reservoir through the inlet valve into the pump chamber, so that the chamber and thus the applicator is ready for its next use.

The or each inlet valve preferably comprises a one-way valve, for example a simple flap valve or a check valve, to prevent medicament advanced into the pump chamber from being returned upstream of the inlet valve. This one-way valve thus ensures that the supply of medicament in the reservoir remains isolated.

When the applicator comprises a cartridge port for connection with a medicament cartridge, the inlet valve of the pump assembly may be disposed on the fluid outlet of the cartridge port. In a preferred arrangement, the inlet valve is disposed on, more preferably within, the central bore of the stopper, and most preferably the central bore contains a shoulder portion against which a valve member, such as a disc or ball, rests or seats to close the inlet. The valve member may bulge under negative pressure within the pump chamber above the shoulder portion to allow medicament to flow into the chamber. The inlet valve member is preferably spring loaded to permit the inlet to open against the spring force (and discharge of medicament into the chamber) under negative pressure in the pump chamber and to close the inlet under the action of the spring on pressure equalisation. For example, the valve may include a valve member, such as a disk, plug, ball, etc., and a separate spring, but may take the form of a unitary valve molding that includes both the valve member and the spring. The unitary valve molding may include an anchor portion for securing the molding relative to the pump chamber and/or the cartridge port, a disk or ball portion for closing the inlet, and a spring portion extending between the anchor portion and the disk or ball portion. It will be appreciated that both the anchor portion and the spring portion act, for example, to permit the flow of medicament into the pump chamber. In a particularly preferred arrangement, the anchor member of the inlet valve moulding may be captured between the detent and the cap member of the cartridge port.

The or each pump chamber of the pump assembly into which medicament is drawn and subsequently expelled may comprise a collapsible chamber whereby the volume of the chamber is reduced under the force applied by operation of the actuator. For example, this collapsible chamber may take the form of a bellows (in which the side walls of the chamber fold concertina-wise), or a rolling diaphragm (in which the end walls of the chamber push inwardly or "roll" as the diaphragm side walls shorten), or a vertical diaphragm (pressed downwardly by the actuator to reduce the chamber volume). In particular, operation of the actuator (which may comprise a pull rod arm and a plunger or, in the case of a vertical diaphragm, an L-shaped pull rod arm, one arm being a pull rod arm and the other arm acting as a plunger, the pull rod arm being pressed towards the applicator body to apply the plunger to the chamber) causes the chamber to contract, thereby causing a positive displacement of the predetermined volume of medicament, the volume of the displacement corresponding to the desired dose of medicament. The displaced volume of medicament is forced out of its chamber through one or more fluid outlets of the pump assembly to one or more dispensing nozzles, and thereby an equivalent volume of medicament is dispensed from the nozzles.

The collapsible chamber, in particular comprising a bellows or rolling diaphragm arrangement, may comprise a resilient material, preferably an elastomeric material. The chamber is advantageously formed in an expanded (non-collapsed) configuration, such as by molding, so that after the actuator is collapsed and released, the collapsed chamber wall returns to its original expanded shape. In the case of a rolling diaphragm, for example, a negatively wound spring may be included to assist in returning the chamber wall to its original non-contracted state and/or returning the actuator to its initial position in preparation for dispensing the next dose. When the collapsible chamber expands upon release of the actuator, a negative pressure is created within the chamber such that a further volume of medicament is drawn into the chamber via the fluid inlet, ready to deliver the next dose.

When the collapsible chamber comprises a rolling diaphragm, it is necessary to guide the chamber such that it collapses in a substantially linear manner. In this regard, the diaphragm may be substantially surrounded by an outer casing so as to guide or confine the side walls of the chamber to force substantially linear contraction. Furthermore, to permit the actuator to operate a collapsible chamber within the housing, the housing is preferably provided with an aperture aligned with the central longitudinal axis of the diaphragm, and a chamber pin is provided which extends through the aperture such that one end of the pin is in contact with the end wall of the diaphragm and the other end is contactable by the actuator. During actuation, the actuator pushes the chamber pin from one end, and the other end of the pin thus pushes the septum to expel the medicament. Thus, the chamber pin reciprocates along the longitudinal (contraction) axis of the diaphragm.

The end of the chamber pin that contacts the diaphragm is preferably also held by the diaphragm, for example by means of a complementary engagement feature on the pin and the diaphragm, so that when the diaphragm springs back to its "uncontracted" shape after dispensing, the pin is held in place against the diaphragm, ready for the next operation. If not positively held against the diaphragm, there is a risk that the tip of the pin may lose contact with the diaphragm under the action of the return force, possibly resulting in misalignment with the diaphragm. In a preferred arrangement, the chamber pin contains a groove adjacent the end of the pin that contacts the diaphragm, and the end wall of the diaphragm contains an outwardly directed central recess, with an internal rib extending into the recess and cooperating with the pin groove to hold the pin in place against the diaphragm.

Other forms of pump chamber are also contemplated. For example, as an alternative to one or more collapsible pump chambers, the chambers may include one or more cylinders, operation of the actuator rod causing each of the pistons to be advanced along the cylinder. Thus, as the pistons are advanced along their respective cylinders, medicament is expelled from the cylinders through the associated fluid outlets. After releasing the pull rod, the piston is retracted along its cylinder, e.g. under the return force of a spring, and the resulting negative pressure within the cylinder enables the cylinder to be refilled with medicament drawn via the fluid inlet, ready to deliver the next dose. Advantageously, the end of the piston member carries a button, pin or the like which is depressed by the actuator lever to advance the piston. The piston may include one or more lip seals for providing sealing of the cylinder wall against leakage of medicament and ensuring that the medicament is expelled through the outlet to the nozzle.

It is preferred that the longitudinal axis of the pump cylinder is transverse to the longitudinal axis of the applicator body (or bobbin) so as to effectively provide horizontal actuation relative to the applicator.

The pump assembly may comprise one or more outlet valves for sealing the fluid outlet from the or each pump chamber to the nozzle under negative pressure within the respective pump chamber and opening the fluid outlet under positive pressure within the respective pump chamber so as to allow the medicament to be expelled to the nozzle. Having these outlet valves helps to avoid any deterioration of the medicament in the pump chamber, thereby substantially preventing medicament that has been expelled to the nozzle from being transferred back to the pump chamber and keeping the pump chamber free of air.

Although many forms of valve may be employed, the outlet valve may advantageously comprise a resilient material, preferably an elastomeric material, to permit the material to deform outwardly away from the or each outlet during application of the expelling force to the pump chamber to enable medicament to be delivered from the pump chamber to the nozzle. In one arrangement, when the pump chamber is a collapsible chamber, the outlet valve and collapsible chamber may be provided as an integral unit. Indeed, the inlet valve, the collapsible pump chamber and the outlet valve may comprise a single integral resilient profile, for example wherein the inlet valve is the profile of a flap valve, formed by stamping the flap valve or the like on a substantially planar portion of the resilient profile, and forming the pump chamber and the outlet valve on appropriately profiled portions of the profile. In another arrangement, the outlet valve may be the same as or substantially similar to the inlet valve, for example, the outlet valve may also comprise an integral valve moulding comprising both the valve member and the spring, as described above. With this type of valve, any anchor portion can be captured between one molded piece that includes a portion of the pump assembly and another molded piece that provides a fluid path to the nozzle.

The material of the chamber walls or lining thereof should ideally be a material which does not degrade due to prolonged contact with the medicament, thereby ensuring that the medicament is not contaminated by degraded by-products, and also ensuring that the applicator can be reused for a long period of time. Options for preferred elastomeric materials for the collapsible pump include silicone, fluoroelastomers, or thermoplastic elastomers.

The actuator of the applicator according to the invention may be disposed towards the rear of the inclined applicator face, with the pump chamber of the pump assembly interposed between the nozzle and the actuator. When the actuator is located on a side portion of the applicator (facing away from the scalp when in use, i.e. in the dispensing position) and the actuator is easily accessible (facing away from the scalp during dispensing and massaging), then the actuator is operated by being moved substantially in the dispensing direction. When the actuator, pump chamber and dispensing nozzle are substantially aligned in this manner, this helps to relieve the force necessary to operate the actuator to dispense the medicament. This is not only particularly advantageous for those users who suffer from, for example, joint stiffness or joint pain (because the effort necessary to dispense the medicament is reduced), but it also makes the applicator suitable for one-handed operation.

For applicators comprising a single nozzle and an application face substantially continuous with each other, the actuator may be positioned below the nozzle and substantially in line with the nozzle. In case an application surface is provided below the nozzle, the actuator may be better positioned on the side of the applicator opposite the application surface to avoid inadvertent operation of the actuator during diffusion of the medicament through the application surface.

The actuator preferably comprises a plunger mechanism for positively displacing medicament from the or each pump chamber. For example, the actuator may include a plunger and a button, whereby depressing the button advances the plunger and displaces the medicament from the pump chamber. More preferably, the actuator may include a plunger and a pull rod arm, rather than a button, which provides a mechanical advantage. The pull rod arm is advantageously angled away from the applicator body from the fulcrum such that the plunger acts on the pump chamber when the pull rod arm and the applicator body are squeezed together. The pull rod arm may be substantially straight or slightly curved, or may be angled, such as L-shaped, with a first leg extending outwardly, substantially perpendicular or oblique to the longitudinal axis of the applicator body, and a second leg depending from the first leg (i.e., away from the applicator head), substantially parallel to the applicator body. In the latter arrangement, actuation may be performed by pushing down on the first leg of the lever arm, or by squeezing the second leg together with the pump body.

Since the size of the area that may need treatment may vary significantly between patients (such as may be a particular location on the scalp), the applicator may be adapted accordingly. Thus for patients with only mild scalp conditions and who need to apply medicament to a relatively small area of the scalp, the applicator may comprise an applicator head with a single nozzle. This single nozzle applicator head can also be used when it is necessary to apply the medicament to an inconvenient or difficult to reach area of the scalp, such as behind the ears or along the hairline. Although not limited thereto, a single nozzle applicator may be used to deliver a dose of medicament in an amount ranging from, for example, 0.05 to 0.1g per actuation. More or fewer doses may be obtained, for example, by appropriately adjusting the volume of the pump chamber.

For patients with more severe scalp conditions and therefore a need to apply medicament over a wider area, the applicator preferably comprises an applicator head having a plurality of spaced nozzles, for example two to six nozzles, preferably two to four nozzles, and most preferably three nozzles. The applicant has found that three nozzles represent a convenient balance of penetration of the hair and spreading of the medicament over a wider area, and that three nozzles are preferred due to the stability achieved; the three nozzles are always able to contact the scalp. Again, although not limited thereto, a three nozzle applicator may be used to deliver three times the dose obtained by an equivalent single nozzle applicator, for example in the range of 0.15g to 0.3g per actuation. As described above, adjusting the pump chamber volume can be used to determine the precise dose.

In the case of a multi-nozzle applicator, the face of the applicator head may have a face area substantially similar to the area of the scalp to be covered by the delivered dose of medicament. For example, the face area of a three-nozzle applicator head may be three times larger than the face area of a single-nozzle applicator.

Of course, the patient's condition may change over time such that the condition may improve from a severe condition to a mild condition, or conversely, the patient may have several areas to treat, which are suitable for single and multiple nozzle treatments. In this regard, rather than providing the applicator with a single user-specific applicator head, the applicator may include a plurality of interchangeable applicator heads each having a different nozzle configuration. Thus, for example, the applicator may be provided with interchangeable single and three nozzle applicator heads.

These interchangeable applicator heads may be provided with an integral pump assembly to allow the user to more easily change the applicator from, say, a single nozzle applicator to a multi-nozzle applicator. It will be appreciated that different fluid outlet arrangements may be necessary depending on the nozzle configuration. For example, although the pump assembly of a multi-nozzle applicator may comprise a single outlet of a single pump chamber, with the fluid passage branching further upstream of the pump chamber, depending on the number of nozzles provided, the pump chamber itself may also have multiple outlets. Alternatively, more than one pump chamber may be provided, each chamber delivering medicament to a respective dispensing nozzle or group of nozzles upon operation of the actuator.

Rather than providing interchangeable heads to supply different required doses, the applicator head of the applicator preferably comprises a plurality of dispensing nozzles and a nozzle selector mechanism which is operable in a first mode to dispense medicament from all of the nozzles and in a second mode to dispense medicament from only one of the nozzles. In this way, the user can select whether to dispense the medicament from a single nozzle (e.g., when applying to only a small area of the scalp) or to dispense the medicament to all nozzles (e.g., when the area to be treated is large).

It has been found that an applicator head comprising three nozzles provides an effective balance between scalp coverage and hair penetration and that each nozzle dispenses a relatively large volume of medicament, typically a drop. Thus, the nozzle selector mechanism preferably dispenses the medicament from a single nozzle in one mode, and in another mode the nozzle selector mechanism dispenses the medicament not only from a single nozzle of the other mode, but also from two additional nozzles. Of course, it will be appreciated that when more than three nozzles in total are provided, the dispensing arrangement is adapted accordingly.

Advantageously, the nozzle from which the medicament is dispensed protrudes beyond the other nozzles when the selector is set in its second mode (that is to say the mode of single nozzle dispensing). In other words, the nozzles of a single dispensing nozzle are preferably larger than the other dispensing nozzles. Thus, when dispensing from a single nozzle, the user is not only able to easily identify the operating nozzle, but is also able to direct the nozzle onto the scalp area being treated and massage the nozzle only on the scalp. Thus, rubbing of other (inactive) nozzles also against the scalp can be avoided, possibly worsening the trouble-free scalp. The individual nozzle tips preferably project 10mm to 15mm beyond the tips of the other nozzles.

In an applicator which is switchable between a single nozzle dispensing mode and a multi-nozzle dispensing mode, the pump assembly may advantageously comprise more than one pump chamber and, upon operation of the actuator, the nozzle selector mechanism is adapted to expel medicament from all pump chambers when in the first mode and to expel medicament from a single pump chamber when in the second mode. By having more than one pump chamber and determining whether to expel medicament from one chamber or all chambers, the dose of medicament dispensed can also be varied. For example, the dose expelled from all chambers at the same time will typically be several times the dose expelled from only a single pump chamber. In this way, the nozzle selector mechanism also dictates the dose dispensed.

In one arrangement, the applicator comprises a pump assembly having two pump chambers, one chamber having a capacity suitable for expelling a dose of medicament to a single nozzle, while the other chamber has a capacity greater than the capacity of the one chamber for expelling substantially the same dose of medicament to each of two or more nozzles. Thus, in the case of an applicator having three nozzles, the capacity of the other chambers is substantially twice that of the first chamber.

Conveniently, a nozzle selector mechanism selectively operable for one or all of the chambers may be integrated with the actuator. For example, the nozzle selector may be integrated with a plunger of the actuator. In a preferred arrangement, the plunger includes a rotatable element that can selectively operate one pump chamber or all of the pump chambers depending on the rotational position of the plunger. More preferably, the plunger may also be rotated to another position in which the plunger is unable to operate all of the pump chambers, effectively providing a locked position of the applicator in which the actuator is operated without dispensing medicament.

When the applicator comprises two (or more than two, but preferably two) pump chambers (each in the form of a rolling diaphragm having associated chamber pins projecting from a diaphragm casing), the rotatable plunger may comprise: a plunger body, an actuator rod extending from a rear of the plunger body, and three or more apertures in a front face of the plunger body, the apertures being spaced in such a way that, upon actuation of the actuator rod, when rotated to a first plunger position, the plunger face advances all of the chamber pins, thereby expelling medicament from all of the pump chambers, when rotated to a second plunger position, the plunger face advances only the chamber pins associated with a pump chamber expelled towards a single nozzle (another chamber pin is received in an aperture such that it is not advanced), and when rotated to a third plunger position, the plunger face does not contact the chamber pins (all of the chamber pins are received in respective apertures) such that medicament is not expelled after actuation.

A dial is preferably provided to the rear of the plunger body to permit the user to select the required dispensing mode, the dial having a central aperture through which the plunger or actuator rod extends. The actuator rod preferably has an asymmetric cross-section and the central dial aperture has a corresponding cross-section such that when the dial is rotated to select a particular mode, the actuator rod and hence the plunger body are simultaneously rotated.

The dial may also be provided with a tab that extends a short distance beyond the outer dial circumference for engagement with a complementary recess on the underside of the actuating lever when the dial ring is in the third non-dispensing (locking) position.

Advantageously, the switching mechanism further comprises an insert interposed between said dial and plunger body, said insert having a plurality of internal lugs, said internal lugs acting as keys, cooperating with external lugs on said plunger body to permit reciprocating (back and forth) movement of said plunger body only when said plunger body is in the pumping (single and multi-nozzle dispensing) or locking position.

Of course, other arrangements for varying the dose dispensed by the applicator may also be provided, and will now be described. For example, the applicator may be provided with a separate dose selector mechanism for permitting the amount of medicament dispensed to change upon operation of the actuator. When the applicator includes both a nozzle selector mechanism and a dose selector mechanism, the volume of medicament dispensed from all nozzles may likewise be several times the volume of medicament dispensed from a single nozzle. Thus, the combination of the nozzle and the dose selector mechanism provides a means of changing the applicator from single nozzle discharge to multi-nozzle discharge and changing the dose of medicament dispensed.

When the dose selector mechanism is operable solely from the nozzle selector mechanism, for example, the user may first operate the nozzle selector mechanism to select single nozzle discharge or multi-nozzle discharge, and then operate the dose selector mechanism to select a dose to be discharged from the selected nozzle.

The dose selector mechanism may be operated by varying the degree of actuation between the first and second modes of operation of the actuator so as to vary the volume of medicament displaced from the pump chamber. For example, when it is desired to dispense medicament from only a single nozzle, the dose selector mechanism may be arranged to limit the extent of movement of the actuator and hence the volume of medicament displaced from the pump chamber, whereas when there is medicament to be dispensed through all nozzles, the dose selector mechanism is arranged such that movement of the actuator (e.g. the pull rod or button thereof) is not limited. It will be appreciated that this arrangement could equally be incorporated onto an applicator having a fixed applicator head (e.g. a single or three nozzle head, including a head incorporating an application face for diffusing a medicament) and onto an applicator having an interchangeable head.

The actuator limiting means may take the form of a switch, such as a lever switch or a dial switch, which in the first position permits full actuation and in the second position permits only limited actuation. The switch may be carried on or adjacent to the actuator itself. For example, when the actuator comprises a pull rod, the switch may comprise a pull rod switch carried on the pull rod itself or on the body of the applicator. In the latter case, the switch may be adapted to move from a first position in which the pull rod is unobstructed to a second position in which the switch partially obstructs movement of the pull rod towards the applicator body.

Whether the actuator is a push button or a pull rod mechanism or the other, the actuator may include a spring or equivalent element for returning the actuator to the starting position for the next actuation. If there is a switch that constrains the actuator, the spring will return the actuator to the proper position set by the switch.

The applicator may further comprise an actuator lock for preventing inadvertent dispensing of the medicament. The lock is effectively engaged when the applicator is contained in a bag (e.g. for travel) and may be used, inter alia, to prevent accidental movement of the pull rod arm.

The actuator lock may take the form of a switch that is movable, such as by sliding or rotating, between a first position in which movement of the actuator, such as the lever arm, is substantially prevented, and a second position in which the lever arm is free to pivot. The switch may be located on the applicator body or head (e.g., on the head assembly including the applicator head), the pump assembly and actuator, adjacent the free end of the pull rod arm (e.g., between the pull rod arm and the body), or on the pull rod arm. Indicia may be provided on the switch or on the applicator body, on the head or pull rod arm adjacent the switch, or any combination thereof to indicate the locked and unlocked positions.

In one arrangement, the actuator lock may be integral with a switch comprising the movement limiting means of the dose selector. In this way, the user may select one of the three switch positions, (i) to prevent any movement of the actuator, (ii) to limit the extent of movement of the actuator so as to dispense a smaller amount of medicament or (iii) to permit unrestricted movement of the actuator so as to dispense a maximum dose of medicament.

The aforementioned actuator lock provides an alternative solution to the rotatable plunger option described above, in which upon actuation of the plunger, the plunger may be rotated to a position in which no interaction with the or each pump chamber occurs.

In another variation of the applicator having a plurality of dispensing nozzles and a nozzle selector mechanism for selecting single or multiple nozzle dispensing, the pump assembly may comprise an integral chamber, for example in the form of a cylinder, having a first fluid outlet on a distal end thereof for expelling medicament to one of the nozzles and a second fluid outlet at an intermediate position along the cylinder for expelling medicament to the remaining nozzles, wherein in a first mode of operation the first and second outlets are open to the chamber so that medicament can be expelled from both the first and second fluid outlets, and in a second mode of operation the second fluid outlet is blocked by a piston in the cylinder so that medicament can be expelled from only the first fluid outlet.

In this arrangement, the nozzle selector mechanism may comprise advancing the actuator rod from a first position in which the piston is fully retracted to allow full expulsion of medicament from the cylinder through both outlets to a second position in which the piston is partially advanced to a position in which the second fluid outlet is blocked by the piston, in which position the cylinder contains a reduced volume of medicament ready for expulsion to a single nozzle. Nozzle selection thus also automatically selects the dose. When switching from multi-nozzle dispensing to single-nozzle dispensing, a certain amount of medicament will be dispensed when the piston is advanced to the second position. This "excess" medicament can simply be wiped off the nozzle outlet and on the next and subsequent operation of the actuator, the correct dose is dispensed from only one nozzle.

In another arrangement, the dose selector mechanism includes a nozzle shut-off (lockout) valve for preventing fluid flow to all but a single nozzle, and a slide switch is included on the pull rod of the actuator mechanism for limiting the extent of permitted movement (rotation) of the pull rod. In operation, when dispensing from only a single nozzle is required, the lockout valve is activated and the actuator switch is slid upward toward the fulcrum to reduce the travel of the pull rod and, thus, the distance the piston can be advanced.

In another alternative arrangement, rather than providing a switch on the actuator lever to limit its movement, a switch may be provided on the applicator body or head which is movable from a first position in which movement of the actuation lever is permitted to displace a first predetermined dose of medicament to a second position in which the switch limits movement of the actuation lever to displace a second smaller predetermined dose of medicament. The switch effectively acts as a wedge between the pull rod and the applicator body or head in order to control the degree of rotation of the actuator pull rod.

In this arrangement, it is desirable that the applicator further comprises a locking valve for preventing medicament from being expelled to all but one dispensing nozzle. Thus, for single nozzle operation, the body switch slides to its second position and the lockout valve is activated; in this way, smaller doses may be dispensed from the applicator. Most preferably, the dose dispensed from a single nozzle will be proportional to the total number of nozzles on the applicator. For a three nozzle applicator, the dose dispensed from a single nozzle will be one third of the dose dispensed when all three nozzles are open.

Of course, there are many other arrangements that permit switching between single-nozzle and multi-nozzle dispensing and actually prevent dispensing altogether. For example, an alternative arrangement may include a plurality of lockout valves operable to block flow to some or all of the nozzles, rather than a single lockout valve preventing flow of medicament to all but one of the nozzles. In the latter case, the valves may be provided on an integrated valve switch, whereby the valve switch is moved in one direction to close each valve in turn. Thus, in one extreme position all valves are closed, in the opposite extreme position all valves are open, and in the intermediate position at least one valve is open while the other valve is closed. This integrated valve switch may be linked to the actuation lever, whereby the lever position determined by the dose selector sets the dispensed dose (determined by the degree of movement allowed) and the number of nozzles effectively closed (determined by the position of the valve switch). Also, as mentioned above, the applicator cover for concealing the application face and nozzle when the applicator is not in use may contain an actuator lock in the form of an arm or the like which acts as a wedge behind the actuator pull rod to prevent movement of the actuator pull rod.

In another example, the actuation lever is simply adapted to provide audible or tactile feedback to the user. Thus, when the pull rod is pressed towards the applicator body, sequential contact may be made between the pull rod and the series of projections so as to produce a sound, typically a "click", which indicates the dose dispensed. Thus, at a first "click" the user will know that a first dose has been dispensed, if the pull rod is further pushed a second "click" will be heard indicating that a double dose of the first dose has been dispensed, and at a third "click" a triple dose of the first dose has been dispensed, and so on. Furthermore, if a separate lockout valve is provided (e.g., a lockout valve closing two of the three nozzles), the user may activate the lockout valve and dispense one, two, or three doses from a single nozzle corresponding to the number of clicks. This arrangement does of course rely on the close attention of the user to dispense the desired dose.

In addition to the applicator for self-administration of a medicament as described above, the present invention is further a method of delivering a semi-solid medicament to the scalp or other body area, the method comprising: loading an applicator body of an applicator with a medicament, the applicator further comprising an applicator head fixed relative to the applicator body and having one or more elongate dispensing nozzles for passing through hair and contacting the scalp, a pump assembly comprising at least one pump chamber having one inlet for receiving a dose of medicament from the applicator body and one or more outlets for discharging medicament to the or each dispensing nozzle, and an actuator operable on the or each pump chamber for pumping the dose of medicament in the chamber through the or each outlet; priming the applicator by operating the actuator to transfer medicament from the applicator body to the pump chamber and the or each nozzle; and thereafter delivering the medicament by contacting the or each nozzle with the scalp or other body area and operating the actuator to pump a dose of the medicament from the chamber through the nozzle onto the scalp or other body area.

It will be appreciated that the loading and priming steps need only be performed initially, before the medicament is first delivered from a new medicament supply to the scalp or body area of the patient. Once filled and primed, the applicator can then be used to deliver a further dose of medicament simply by operating the actuator.

The step of loading an applicator with medicament preferably comprises inserting a dispensing end of a cartridge containing medicament into a cartridge port on the applicator, the cartridge port being in fluid communication with the inlet of the pump chamber.

Additionally, the present invention is further an applicator system characterized by the applicator described above, said applicator having: a cartridge port for receiving a dispensing end of a cartridge, the port being in fluid communication with the or each inlet of a respective pump chamber of a pump assembly; and a cartridge containing the medicament.

The present invention also encompasses a dispenser system for semi-solid formulations, that is, formulations having properties intermediate between solid and liquid, including but not limited to gels, ointments, creams, and the like. In particular, the invention may also be expressed as a system for dispensing a semi-solid formulation comprising: a dispensing head and a cartridge for the formulation, the cartridge having a dispensing nozzle for engagement with the dispensing head; and a plunger for advancing along the cartridge when dispensing the formulation, wherein the dispensing head comprises a cartridge port containing a stopper for insertion therein and sealing against the cartridge nozzle when the cartridge is engaged with the cartridge port, the stopper having a bore therethrough for permitting flow of formulation from the cartridge to the dispensing head via an inlet valve during a dispensing operation, and wherein the stopper bore is provided with a vent, and the dispenser head contains a passageway having a constriction section in fluid communication with the vent, whereby formulation displaced by the stopper when inserted into the cartridge nozzle is forced into the bore and out through the vent into the constriction passageway whereupon the pressure necessary to force formulation further into the passageway becomes greater than the pressure necessary to move the cartridge plunger, and any further displacement of formulation is accommodated in the cartridge by reverse movement of the plunger.

It will be appreciated that with the foregoing dispensing system, when the stopper of the dispensing head is inserted into the cartridge nozzle (as would occur on the assembly of the two components), air in the nozzle above the formulation fill line is purged through the vent and flows freely through the passageway, including through the constricted section, prior to displacement of any formulation. In this way, air is thus purged from the cartridge and dispensing head assembly, facilitating efficient subsequent dispensing. In particular, the need to prime the resulting assembly is substantially avoided or at least significantly reduced. Furthermore, a large amount of formulation is not lost from the cartridge when the system is assembled, as the constricted passage effectively ensures that the displaced formulation is largely retained within the cartridge by expanding the volume of the cartridge when the plunger is forced rearwardly. The presence of a constricted passageway means that only a relatively small volume of formulation can be expelled from the cartridge.

Cartridges of the type described are typically subjected to an automated filling process, but manufacturing tolerances in formulation density, variations in filling lines and component dimensions may all affect the resulting filling level of formulation in the cartridge. Thus, the volume of air above the fill level that needs to be displaced in the cartridge nozzle before the formulation can flow into the dispensing head can vary considerably. The length of the stop is therefore preferably such that, when fully inserted into the cartridge nozzle, its front end projects beyond the minimum filling level of the cartridge. In this way, the stopper ensures that, once assembled, the air above the filling line is displaced substantially together with a certain volume of formulation. In a particularly preferred arrangement, the stop extends substantially the entire length of the cartridge nozzle when fully inserted.

In practice, the volume of displaced formulation will depend on the actual fill level, but the volume of the passage (at least the portion of the passage before (upstream) the constriction section) is to be determined to contain a relatively small volume of formulation, preferably a volume that is less than the total volume of formulation that would be displaced by the stopper if the cartridge was filled only to the minimum fill level. The capacity of the passageway (containing the provided chamber) preferably exceeds about 0.5cm3, which is a typical volume difference between the minimum and maximum fill levels, and therefore will displace about the maximum volume of air. In dispensers having a pump chamber for dispensing a dose of about 0.05cm3 of formulation, this access capacity means that at least 10 aspirations of the dispenser during a filling operation can be avoided.

Preferably, the inlet valve is provided in the stopper bore, for example there may be a valve seat projecting from the inner bore wall into the bore against which the valve member rests to close the valve. The valve seat preferably comprises an inclined surface and the valve closing member preferably comprises a ball. The inlet valve is preferably spring loaded and the spring assembly, which is preferably also housed within the stopper bore, may be integral with or separate from the valve closure member (e.g. a ball).

It will be appreciated that it is critical that those components of the dispensing system which come into contact with the formulation are made of materials which are compatible with the formulation. In this way, contamination of the preparation and any deterioration of the dispenser parts can be avoided. This is particularly important for valves as any incompatibility with the valve closure member or spring can lead to failure of the valve and leakage of the formulation from the dispenser. The beads are therefore preferably metal or plastic beads, for example made of low-density polyethylene (LDPE) or fluorocarbon elastomers (FKM rubber), and the springs can also be made of metal or plastic, LDPE being particularly preferred. In the case where the beads are spherical and made of molded plastic, the beads may have to be post-processed after removing any defects around the mold lines that might otherwise compromise the integrity of the beads. Alternatively, the ball may be molded with an integral peg of a spring, and in such a case, post-processing of the spherical surface of the ball may not be required. Further preferred details regarding the valve are provided elsewhere herein, it being understood that those details and the above details apply equally to the dispenser system and pump applicator described in accordance with the various aspects of the present invention.

In a preferred arrangement, the vent is located adjacent the inlet valve. By such means, the bore can substantially fill the formulation upstream of the inlet valve as the stopper is advanced into the cartridge nozzle. More preferably, the bore contains an internal tube of restricted diameter and length (that is, diameter and length less than that of the bore) extending from the inlet valve. For example, the inner tube may extend from the valve seat into the borehole. Most preferably, the inner tube extends into the bore beyond the vent opening but terminates substantially before the end of the stopper, preferably before the midpoint of the stopper. When the dispenser head and cartridge are assembled, the restricted diameter of the inner tube means that the formulation displaced by the stopper flows along the bore as far as the inner tube, thus forcing the formulation around the outside of the inner tube to the vent opening and beyond the passage of the vent opening. In other words, the inner tube functions in the manner of a straw.

The length of the inner tube is desirably, for example, of small volume, so that after assembly of the cartridge and dispenser head, a first actuation of the dispenser (for example by pumping) will cause any residual air to be purged from the inner tube and cause the formulation to be drawn into the inner tube to the inlet valve. In this way, the valve closing member (typically a ball) will be immediately wetted by the formulation, resulting in an improved seal and thus more efficient filling of the dispenser.

Preferably, air and formulation are expelled to a first pathway section, permitting free flow of the expelled air and formulation, followed by a second section that is constricted relative to the first section, permitting free flow of air, but providing resistance to formulation flow, and thereby creating a backpressure when formulation is flowed into it. The counter pressure causes the plunger to move in the cartridge in the opposite direction in order to accommodate more displacement of the formulation.

The passageway may comprise a continuous space formed between the stopper and the distribution head manifold, which together preferably define the cartridge port, or may comprise one or more channels between the stopper and the manifold. For example, the passageway of the tightening segment may be provided in the form of one or more channels of smaller cross-section than in the first segment, more preferably in the form of complementary threaded segments between the stop and the manifold, effectively creating an elongate helical channel. The continuous change in direction of the pathway provided by the helical channel creates a constriction that prevents the formulation from flowing and creates a backpressure when the formulation is forced along the channel.

In a preferred arrangement, the stopper may comprise a double-walled component, wherein the inner wall provides a central bore through which the formulation passes from the cartridge to the dispenser head, for example via an inner tube in the bore as described above, and the outwardly directed surface of the outer wall seals against the inner wall of the cartridge nozzle, for example by means of a lip seal or the like. The gap between the inner stopper wall and the outer stopper wall forms a substantially U-shaped cylindrical channel which is closed at the front end to force the formulation into the central bore when the stopper is inserted into the cartridge nozzle. In this arrangement, a vent is provided through the inner wall of the stopper, whereby air and formulation displaced by advancing the stopper in the cartridge nozzle is first forced along the bore towards the vent and then out of the vent of the passageway.

The passageway is most conveniently provided by a gap or space between the retainer and the manifold. For example, the channel of the double-walled retainer may be adapted to receive and accommodate a tubular portion of a dispenser head manifold, and the tubular portion and the cylindrical channel are dimensioned relative to each other, e.g., to form a passage therebetween through which air and agent are forced through the vent. For example, the passageway follows a path that first follows the outwardly facing surface of the inner retainer wall down, along the base of the channel, and up the outwardly facing surface of the outer retainer wall. Advantageously, the constricted section of the passageway is formed by complementary threaded sections on the inwardly directed face of the external stopper wall and on the outwardly directed face of the manifold tubular portion, preferably adjacent the open end of the U-shaped channel.

Advantageously, the dispensing head further comprises a chamber into which the displaced air can be contained, this chamber preferably being provided downstream of the tightening channel, for example at the end of the aforementioned threaded section. The chamber is preferably sealed by the cartridge nozzle when the cartridge is assembled with the dispensing head. In this way, the formulation within the dispenser is effectively contained within the sealed system and any loss of effectiveness of the formulation due to oxidation is substantially avoided. In a preferred arrangement, the manifold may comprise a continuous wall depending into the chamber, said wall sealing against the nozzle when the cartridge is in the fully inserted position. The manifold seal wall is preferably concentric with the tubular portion that extends into the channel of the double wall retainer.

The manifold may additionally comprise a connection feature for securing the cartridge to the dispensing head, for example having a threaded portion for screwing the dispensing head onto a complementary threaded portion on the cartridge, preferably around the base of the cartridge nozzle. Preferably, the manifold and cartridge are provided with a one-way locking mechanism to permit assembly of the dispenser head with the cartridge but prevent separation thereof once assembled. For example, the manifold may include one or more, preferably opposed, pairs of head locking clips that press against an engagement rib on the cartridge (e.g., provided on an outer ring, concentric with the nozzle) when the cartridge is screwed onto the dispenser head, but that act as a barrier to the rib when an attempt is made to unscrew the assembly.

When the manifold forms part of an applicator head as described above, the manifold may incorporate the pump chambers of the pump assembly. Similarly, the manifold may house the outlet valve of the pump assembly.

It will be appreciated that the dispensing system according to this further aspect of the invention may be incorporated into the applicator described above, but is not limited to use in such an applicator. In particular, the dispensing system may be deployed with any form of dispensing head, whether the formulation is dispensed from a nozzle or other form of opening in the dispenser head, and whether the dispenser head is adapted to deliver a dose volume of formulation, for example from a pump chamber, or otherwise. Of course, the dispensing system of the present invention is particularly suitable for use in applicators according to other aspects of the present invention, and it will be appreciated that the dispensing system according to this further aspect may include some or all of the necessary optional and preferred features of the applicator set out herein. Likewise, applicators according to other aspects of the invention may include some or all of the necessary optional and preferred features of the dispensing system.

For the avoidance of doubt, the term semi-solid formulation as used herein with respect to a dispensing system is intended to encompass both pharmaceutical and non-pharmaceutical formulations which may flow or be extruded or spread, including but not limited to gels, creams, ointments and the like.

Drawings

The invention will now be described, by way of example only, with reference to the following drawings, in which:

figures 1a to 1d are views of a single nozzle scalp applicator with a cartridge according to a first aspect of the present invention;

FIG. 2 is a perspective view of the applicator of FIGS. 1a to 1d without the bobbin;

FIGS. 3a to 3e are views of a three nozzle scalp applicator with a cartridge according to another aspect of the present invention;

FIG. 4 is a perspective view of the applicator of FIGS. 3a to 3e without the bobbin;

figures 5a to 5c are views of a switchable applicator with a cover;

figures 6a to 6c are views of a cartridge with a closure for use with an applicator according to the present invention;

fig. 7a to 7c are views of the cartridge of fig. 6a to 6c without the cover;

FIG. 8 is a cross-section of the applicator according to FIGS. 3a to 3e with the cartridge but with the pump assembly, plunger and dial omitted;

FIG. 9 is a partial cross-section of the applicator according to FIGS. 3a to 3e including a pump assembly, plunger and dial;

fig. 10 is an enlarged cross-section of the applicator head of the applicator of fig. 3a to 3 e;

FIG. 11 is an enlarged partial cross-section of the pump assembly of the applicator of FIGS. 3a to 3 e;

FIG. 12 is a perspective view of the pump assembly of the switchable nozzle scalp applicator;

FIG. 13 is a perspective view of the pump assembly of the single or three nozzle scalp applicator;

fig. 14 is an exploded perspective view of the switching mechanism of the switchable three nozzle scalp applicator;

15 a-15 c show the locked position, single nozzle pump position, and three nozzle pump position, respectively, of the switching mechanism of FIG. 14;

FIG. 16 is a perspective view from the rear of an insert of the switching mechanism of FIG. 14; and

fig. 17a to 17c are cross sections through the plunger body and insert of the switching mechanism of fig. 14 in various relative positions.

FIGS. 18a and 18b are views of an alternative single nozzle applicator for application to the scalp and other body areas; FIG. 18c is a view of a similar fully disposable applicator;

FIG. 19 is a partial cross-section of the applicator head, pump assembly and actuator of the applicator of FIGS. 18a and 18 b;

FIG. 20 is a partial cross-section of an applicator head of the applicator of FIGS. 18a and 18b equipped with an alternative pump assembly and actuator;

FIG. 21 is a perspective view of a single nozzle applicator having a first configuration;

FIG. 22 is a perspective view of a single nozzle applicator having a second configuration;

FIG. 23 is a perspective view of a single nozzle applicator having a third configuration;

FIG. 24 is a perspective view of a single nozzle applicator having a fourth configuration;

FIG. 25 is a perspective view of a single nozzle applicator having a fifth configuration;

FIGS. 26a and 26b are partial cross-sections of a fully disposable applicator showing first and second pull rod actuator positions;

figures 27a to 27d are perspective views of an alternative valve for an applicator according to the present invention;

28a and 28b are schematic partial cross-sections through the head assembly and cartridge illustrating a first filling arrangement;

FIGS. 29a and 29b are schematic partial cross-sections through a head assembly and a cartridge illustrating an alternative filling arrangement;

FIGS. 30a to 30c are schematic cross-sections through a cartridge with a cartridge cover for another filling arrangement;

FIGS. 31a to 31c are perspective views of an alternative cap for a single nozzle applicator in accordance with the present invention;

figures 32a to 32d are cross-sectional views of another alternative applicator incorporating a dispenser system according to another aspect of the present invention;

figures 33a to 33d illustrate an assembly sequence of the applicator/dispenser head and cartridge of the applicator of figures 32a to 32 d;

FIG. 34 is an enlarged partial cross-section from FIG. 32d illustrating the displaced air and formulation flow path;

FIG. 35 is a cross-sectional view of a cartridge with a cap for use with the applicator/dispenser of FIGS. 32a to 32 d;

fig. 36 is a perspective view of the applicator/dispenser head and cartridge of the applicator/dispenser of fig. 32a through 32d, illustrating a one-way locking arrangement; and

fig. 37 is a cross-section through the assembled applicator/dispenser of fig. 36 in a locked configuration.

Detailed Description

In fig. 1a to 1d, an applicator 10 is shown having an applicator body 12 and an applicator head 14. The applicator body 12 is closed at its lower end by an end cap 22, the end cap 22 being part of a cartridge 20 mounted on the applicator. Fig. 2 shows the open end of the applicator body 12 into which the cartridge 20 is inserted.

A single nozzle 40 projects from the inclined applicator face 16 on the applicator head 14, said nozzle comprising a nozzle stem 42, the nozzle stem 42 terminating in a nozzle tip 44 of softer material than the stem. The nozzle bar 42 tapers outwardly where it engages the applicator face 16 to provide strength and a smooth profile for easy cleaning. The nozzle tip 44 has a pair of opposed side ports 45 through which the medicament is dispensed to the scalp.

The applicator 10 includes an actuator 30 in the form of a pull rod arm 32 and an actuator rod 39, the actuator 30 being pushable in by the pull rod arm 32 to press a plunger 34 (not visible) within the applicator body 12 against a pump chamber 50 (not visible) of the pump assembly. The applicator 10 has a dial 70 with a tab 72, the tab 72 being interlockable with a recess on the rear side of the pull rod arm 32 at its distal end to prevent accidental actuation, for example during storage or transport of the applicator. The dial 70 is rotatable about the central axis from a locked position to an unlocked position as shown in fig. 1c, in which the actuator rod 39 can be pushed in by pressing the pull rod arm 32 towards the applicator body 12 in order to dispense a dose of medicament from the nozzle 40.

Fig. 3a to 3e show an alternative applicator 10 having an enlarged applicator head 14 compared to the applicator of fig. 1 and 2, this time with three nozzles 40, 40a extending from the applicator face 16. Fig. 4 shows the applicator 10 without the cartridge 20 assembled. The nozzles 40, 40a are arranged in a triangular arrangement on the applicator face 16, the uppermost nozzle 40a on the applicator face 16 having a nozzle stem length greater than the other two lower nozzles 40, the two lower nozzles 40 being of equal length. The nozzle tips 44 of all three nozzles are positioned in the same plane so that they all contact the scalp of the user when the medicament is dispensed through all three nozzles 40 at the same time. When the applicator 10 is held at a different angle relative to the scalp, it is possible that only the longer nozzles 40a contact the scalp, with the scalp being oriented for dispensing from only the longer nozzles 40 a.

The applicator 10 also has a pull rod arm 32 and an actuator rod 39, the actuator rod 39 being pushed in by the pull rod arm 32 to press the plunger 34 (not visible) within the applicator body 12 against the pump chamber 50 (not visible) of the pump assembly. Similarly, there is a dial 70 having a tab 72 for interlocking with a recess on the rear side of the lever arm 32 to provide protection against accidental dispensing of medicament. The dial 70 is rotatable about the central axis from a locked position as shown in fig. 3d to a first unlocked position as shown in fig. 3e (in which the actuator rod 39 can be pushed in to dispense a dose of medicament from all of the nozzles 40, 40a by pressing the pull rod arm 32 towards the applicator body 12) and further to a second unlocked position (not shown) (in which the actuator rod 39 operates to dispense medicament from only the longer nozzles 40 a).

Figures 5a to 5c show a switchable applicator 10 fitted with a cap 18 to protect the nozzle 40, 40a of the applicator when not in use, for example for storage or transport. The cap 18 has a thickened rim (not shown) which is caught and held by a corresponding recess (not shown) around the periphery of the applicator head 14 to hold the cap 18 in place. The cap 18 is made of a flexible material so that it can be pried away from the applicator head 14 when the applicator 10 is ready for use. A series of ribs 19 on opposite sides of the lid 18 provide a gripping function for assisting the user in removing the lid.

Fig. 6a to 6c show a cartridge 20 for all variants of the scalp applicator 10, including the variants of fig. 1 and 3. The cartridge 20 is provided with a cover 24 or top which is removed prior to assembly in the applicator 10.

Fig. 7a to 7c correspond to fig. 6a to 6c, with the cover 24 removed. The dispensing or outlet end 26 of the cartridge 20 includes a locking flange 28 which interlocks with a corresponding recess in the cartridge port 80 adjacent the applicator, as will be seen in fig. 8. The cartridge 20 may thus be fitted to the applicator 10 by: the cartridge cover 24 is first removed, the cartridge 20 is inserted such that the outlet end 26 enters the cartridge port 80 and the flange 28 abuts the shoulder 82 of the cartridge port 80 to indicate that the cartridge is fully inserted, whereupon the cartridge 20 is twisted 90 ° such that the locking flange 28 is in interlocking relationship with the recess adjacent the cartridge port 80.

Fig. 8 shows the cartridge 20 assembled to the applicator 10 and, for simplicity, the pump assembly and dial etc. are not shown. When fully inserted, the end cap 22 of the cartridge 20 abuts the open end of the applicator body 12, effectively forming a continuous sealed outer surface that is easily wiped off, thereby maintaining the applicator in a clean, sanitary condition.

Fig. 9 provides a more detailed cross-section of the applicator 10 of fig. 3a to 3e in the region of the applicator head 14 and upper applicator body 12. The applicator 10 is of the type having two rolling diaphragms 51 (only one visible) of different volumes for the pump chamber 50, each diaphragm 51 being housed in a casing 52 of suitable dimensions, the casing 52 having a central aperture 53 through which a respective chamber pin 55 protrudes 53. The chamber pins 55 are held in outwardly directed recesses 56 on their respective diaphragms 51, the recesses 56 having ribs 57, the ribs 57 engaging with the grooves 54 on the chamber pins 55.

The outlet 66 (visible in figure 9) for the medicament expelled from the diaphragm 51 (but shown in more detail in figure 11) leads only to the uppermost nozzle 40a, i.e. the longer of the three nozzles on the applicator head 14.

Fig. 10 provides more detail of the nozzle configuration and the fluid path leading from the pump chamber 50 (diaphragm 51). The nozzle stem 42 has an end port 43 and a nozzle tip 44 having opposite side ports 45 is fitted over the end of the nozzle stem 42. A nozzle tip 44 of elastomeric material is retained on the nozzle stem 42 by stretching over the end of the stem whereupon internal ribs on the internal rim of the tip 44 spring into corresponding grooves around the stem end.

As shown in fig. 11, the rolling diaphragm 51, the clapper inlet valve 61 and the outlet valve 62 may be provided as a unit by moulding a resilient material to provide the necessary shape of the diaphragm and the outlet valve, and then stamping the material to provide the clapper inlet valve 61.

Fig. 12 is a perspective view of a portion of a pump assembly suitable for a switchable applicator 10, specifically switchable between single nozzle dispensing and three nozzle dispensing. The dual inlet 63 provides a fluid path to two rolling diaphragms 51 (not visible) housed in respective housings 52, the housings 52 having chamber pins 55 extending therethrough. An elastically deformable outlet valve 62 is provided for each diaphragm chamber 50.

Fig. 13 shows parts equivalent to those of fig. 12, but intended for use in a single or three nozzle applicator 10. Only one rolling diaphragm 51 (not visible) is provided, the capacity of which varies depending on whether the applicator 10 is a single nozzle or a three nozzle applicator. The diaphragm 51 is housed in an associated casing 52, having a single inlet 63 for receiving medicament from the cartridge 20, one deformable outlet valve 62 and a single outlet to a single nozzle 40 a.

Fig. 14 is an exploded view of a switching (nozzle selector) mechanism for incorporation in an applicator 10 that can be operated in either a single nozzle or a three nozzle dispensing mode depending on the selection made.

The pump manifold 64 has a dual inlet 63, first and second rolling diaphragm chambers 51 (not visible), each with an associated casing 52 and chamber pin 55. The chamber fed to the single nozzle 40a has half the capacity of the other chambers fed to the remaining two nozzles 40, and therefore the enclosure 52 is also of a different size. However, the respective chamber pins 55 project to the same plane, which is parallel to the front face 38 of the plunger body 36.

The rotatable plunger body 36 is provided with spaced apart apertures 37 on its front face 38, these apertures 37 being able to receive one or two chamber pins 55 depending on the mode selected when the plunger body 36 is pushed in. An actuator rod 39 extends from the rotatable plunger body 36 and projects beyond the rear of the plunger body. The actuator rod 39 has an asymmetric cross-section that is slotted through a similarly shaped asymmetric aperture 74 in the dial 70. The insert 90 between the plunger body 36 and the dial 70 has an internal ledge 92, the internal ledge 92 preventing the actuator rod 39 from moving back and forth unless the plunger body 36 is in a correct position.

As shown in fig. 15a, if the plunger body 36 is in the "locked" position, when the actuator rod 39 is pushed, both chamber pins 55 enter the apertures 37 in the plunger body 36, and thus the pins 55 are not pushed. Since it is the pin 55 that causes its respective rolling diaphragm 51 to contract, no medicament is dispensed from this position.

Fig. 15b shows the plunger body 36 in the dispensing position of the single nozzle 40a, in which one of the pump pins 55 enters the aperture 37 in the plunger body 36 when the actuator rod 39 is pushed, and the other pump pin 55 is pushed by the front face 38 of the plunger body 36, thereby expelling medicament from one pump chamber, obviously the pump chamber feeding the single nozzle 40 a.

Fig. 15b shows the plunger body 36 in a three nozzle dispensing position, wherein when the actuator rod 39 is pushed, the two pump pins 55 are pushed by the front face 38 of the plunger body 36, thereby expelling medicament from the two pump chambers 50 and causing medicament to be dispensed from all three nozzles 40a, 40.

Fig. 16 shows the feature of the insert 90 of fig. 14 in more detail, noting that the four equidistant internal tabs 92 act as keys for the plunger body 36, allowing the plunger body 36/actuator rod 39 to be advanced only when the plunger body 36 is in a locked (non-dispensing) position or in a single or three nozzle dispensing position. The insert 90 has a central circular aperture 94 through which the actuator rod 39 can pass.

The multiple relative positions of the plunger body 36 and insert 90, which permit three-nozzle pumping, no pumping, and single-nozzle pumping, are shown in sequence in fig. 17 a-17 c. It will be clear from fig. 17b that the insert's key 92 does permit slight movement either side of the locked position to rotate the dial 70 and thus release the pull rod arm 32 in interlocking with the tab 72 of the dial.

Fig. 18a and 18b illustrate an alternative single nozzle applicator 100 for dual use, namely for applying medicament to a body area shown oriented by the applicator in fig. 18a, and for applying medicament to the scalp shown oriented in fig. 18 b. The applicator 100 comprises an applicator body 112, the applicator body 112 being closed at its lower end by an end cap 22, the end cap 22 being part of a replaceable medicament cartridge 120. The applicator head 114 has a narrowing nozzle 140, the nozzle 140 extending from the progressively convex application face 96 and being continuous with the application face 96, being inclined relative to the longitudinal axis of the applicator body, this application face 96 being intended to spread the dispensed medicament over an area of the body outside the scalp. The medicament is dispensed by squeezing the pull rod arm 132 against the applicator body 112, which action presses a plunger (not visible) within a pump chamber (not visible) to force the medicament through the nozzle 140 and out through a nozzle tip 144 made of an elastomeric material. When used to apply a medicament to the scalp, the nozzle tip 144 is gradually pushed towards the scalp, thereby spreading the hair apart as the nozzle tip is pushed in, and once the tip is against the scalp, the lever arm 132 is squeezed, thereby dispensing the medicament from the nozzle outlet directly onto the scalp. The nozzle tip 144 is then used to spread the dispensed medicament over an adjacent area of the scalp. When only a small body area is to be treated, the nozzle tip 144 may likewise be used to diffuse dispense medicament over that area, rather than using the applicator face 96.

Fig. 18c shows an applicator similar to that of fig. 18a and 18b, but this applicator is entirely disposable. In other words, the applicator is not intended to be used with a replaceable cartridge, but instead the entire device will be discarded once the medicament reservoir is exhausted.

A partial cross-section through the applicator head 114, pump assembly and actuator of the applicator of fig. 18a and 18b is provided in fig. 19. The dispensing tip 126 of the cartridge 120 is fluidly connected to the applicator head 114 via the cartridge port 180 and is locked to the applicator by means of locking tabs 128, these locking tabs 128 interlocking with the projections 132 on the applicator body when the cartridge is inserted and then rotated. The cartridge port 180 leads to a one-way inlet valve 161 through which one-way inlet valve 161 permits medicament from the cartridge 120 to flow to the pump chamber 150. The chamber 150 has a rolling diaphragm (sometimes referred to as a diaphragm pump) 151, and a chamber pin 155 can operate on this rolling diaphragm 151, the pin being urged to reduce the volume of the chamber 150 when the lever arm 132 is squeezed. As the chamber pin is advanced, the medicament is prevented from being forced back into the cartridge by the inlet valve 161 and instead out of the chamber 150 through the outlet valve 162 and into the bore 98 of the nozzle 140, from where it is expelled through the nozzle tip 144 onto the scalp or skin of the user.

The lever arm 132 pivots about a fulcrum within the applicator head 114 behind the nozzle 140, the arm extending away from the applicator body 112 below the nozzle 140 in the manner of a trigger.

The applicator may include a vertical diaphragm pump as in fig. 20, instead of the diaphragm pump shown in fig. 19. In this arrangement, the pull rod arm 132' is substantially L-shaped, having a first arm 132' a that is substantially transverse to the longitudinal axis of the applicator body 112 and a second arm 132' b that depends substantially at right angles to the first arm. The pull rod arm 132 'pivots about a fulcrum within the applicator head 114 adjacent the rear of the applicator face 96 such that upon squeezing the second arm 132' b toward the applicator body 112, the first arm 132'a is forced downwardly against the diaphragm pump 98, which in turn is driven downwardly to reduce the volume of the pump chamber 150'. The pressure in the pump chamber thus increases which will prevent the one-way inlet valve 161 'from opening but does cause the outlet valve 162' to open, thereby expelling the medicament into the bore of the nozzle 140 which is then expelled through the nozzle tip 144 onto the scalp or skin of the user.

The angle of inclination and orientation of the application surface relative to the applicator body and nozzle can be varied, as can the position of the actuating lever. A number of variations of the applicator configuration are illustrated in fig. 21 to 25, each of which illustrates a dual function applicator suitable for both scalp and body applications.

For example, fig. 21 shows an applicator similar to that of fig. 18a and 18b, but with the application face 96 and the narrowing nozzle 140 inclined at a greater angle relative to the applicator body 112. The underside of the narrowing nozzle 140 is substantially flat, while the upwardly directed surface of the nozzle is gradually rounded and continuous with the applicator surface 96. Although the pull rod arm 132 is shown below the nozzle 140, it could equally be located on the opposite side of the applicator body 112, extending below the lower end of the applicator face 96.

In fig. 22, the applicator head 114 has a pair of opposed outwardly facing (side) application faces 96a, 96b between which a tapered nozzle 140 extends at an upwardly inclined angle relative to the applicator body 112.

The applicator of fig. 23 is more similar to the applicator of fig. 21, but differs in that the angle of extension of the application face 96 and the nozzle 140 is not so sharply inclined, and the application face 96 is substantially circular, rather than elliptical. Further, while the transition between the application face 96 and the nozzles 140 is still a smooth transition, the nozzles are angled downwardly relative to the application face.

In each of the illustrated variations of fig. 21 to 23, the tie rod 132 is located below the nozzle 140. However, FIG. 24 shows a further variation in which the pull rod 132 is not only oriented opposite the nozzle 140, but the nozzle 140 is substantially suspended above the applicator surface 96. In this variation, the lower face of the nozzle 140 is substantially flat and the upper face is circular.

In fig. 25, the applicator head 114 is offset relative to the applicator body 112, and the application face 96 and nozzle 140 extend substantially parallel to the longitudinal axis of the applicator body. The applicator surface 96 and the underside of the nozzle together provide a continuous surface for spreading the medicament over the body area.

Fig. 26a and 26b show a partial cross-section of a fully disposable applicator according to another aspect of the invention, in which the head assembly 214 is mounted to a cartridge 220. The cartridge port of the head assembly 214 includes a stop 282, the stop 282 having a lip seal 284 that seals against the inner wall of the cartridge neck 222. The upper discharge end of the bobbin neck 222 has an inwardly directed flange 224 which prevents the lip seal 284 from returning over the flange once the bobbin 220 has been inserted and thus prevents the bobbin neck 222 from separating from the head assembly 214. The head assembly 214 includes an actuator including a horizontal force pump having a piston 260 with a lip seal 262 in sealing contact with the interior cylinder wall of the pump chamber 250. The plunger 260 carries a button 255 at its end against which the lever arm 232 of the actuator acts to drive the plunger 260 along the cylinder against the force provided by the spring 256. Fig. 26a shows the head assembly 214 prior to actuation by the actuator pull rod 232, and in this position, the pump chamber 250 is loaded with medicament from the cartridge 220. When the pull rod 232 is pressed, for example by squeezing towards the cartridge, the piston 260 is advanced through the pump chamber 250 in order to dispense the medicament, as illustrated in fig. 26 b. Specifically, due to the pressure of the medicament being evacuated from the pump chamber 250, the inlet valve 261 remains closed, but the outlet valve 263 is forced open, allowing medicament to pass therethrough to the nozzle 240 whereupon a dose of medicament is expelled from the nozzle tip.

Figures 27a to 27d are perspective views of alternative valves for an applicator according to the present invention, for example for an applicator as shown in figures 26a and 26 b. Each of the valves of fig. 27a to 27c includes a valve member, a spring and an anchor portion, while the valve of fig. 27d includes only a ball 330 and a spring 333. In fig. 27a there is shown a unitary valve moulding 310 comprising a substantially hemispherical valve member 320, this valve member 320 being urged in use against a valve seat (not shown) by a spring portion 322. The valve member 320 includes an extension 321, the extension 321 remaining captured in the fluid path, ensuring that the valve member does not become misaligned relative to the valve seat. The valve of figure 27a comprises an anchor portion 325, the anchor portion 325 being substantially cross-shaped, the outer portion of each arm being able to be captured between opposing surfaces in the cartridge port or pump chamber. In fig. 27b, where the valve is again a unitary moulding 310, rather than the spring portion depending from the anchor portion, the valve member 320 is suspended in this figure on a resilient arm 327, the resilient arm 327 extending generally from the annular anchor portion 326 and lying parallel to the annular anchor portion 326. When a force is applied to the valve member 320, for example when medicament is forced out of the pump chamber (in the case of an outlet valve) or when medicament is drawn from the cartridge into the pump chamber (in the case of an inlet valve), the valve member is urged upwardly against the return force exerted by the resilient arm 327, thereby opening the valve. The valve of fig. 27c is similar to the valve of fig. 27b, but is not a unitary moulding.

Fig. 28a and 28b are schematic cross-sections through the head assembly 214 and the cartridge 220, illustrating a first filling arrangement in which air seeps through the interface between the head assembly and the cartridge. The head assembly 214 includes a stop 282, the stop 282 attached to a cap 288, and an integral valve molding 310, generally of the type shown in fig. 27a and 27b, anchored therebetween. The stop 282 has an external spiral lip seal 340 that allows air to escape when the stop is pushed into the cartridge neck 222 during assembly of the cartridge 220 onto the head assembly 214. When the head assembly 214 becomes fully engaged with the cartridge 220, the stopper 282 applies pressure to the medicament in the cartridge once all air has been evacuated. When the medicament enters the thread-like channel 344 formed by the spiral seal 340, the resulting backpressure acts to push the cartridge plunger (not shown) back down the cartridge body, thereby avoiding spillage of the medicament. To lock and seal head assembly 214 to cartridge 220, the cartridge is twisted at least several turns to compress flange seal 346 on stop 282 between the upper end face of the cartridge neck portion and cartridge cover member 288 when groove 348 on cover member 288 engages external thread 350 of the cartridge neck portion.

An alternative filling arrangement is shown in fig. 29a and 29b, in which a chamber 360 formed between two walls 362a, 362b of the cartridge neck 222 is used to receive any medicament that escapes as the stopper 282 is advanced into the neck. In this arrangement, the stop 282 comprises a cap portion 388 (rather than a separate cap member), the cap portion 388 providing a seal against the outer neck wall 362 a. The cap portion 388 has two concentric walls 390a, 390b for sealing against the inner and outer neck walls 362a, 362b, respectively, once the stopper 282 has been fully advanced, thereby isolating any medicament 400 spilled into the chamber 360. In this arrangement, the insert 380 captured within the retainer 282 serves to anchor the inlet valve 310 and provides the valve seat 316. The head assembly 214 is fitted to the cartridge 220 in a manner similar to the arrangement shown in figures 28a and 28b, i.e. by first pushing the head assembly onto the cartridge and then by twisting the cartridge to lock and seal the head to the cartridge.

Another dispensing arrangement is shown in fig. 30a to 30c, which are schematic cross-sections through a cartridge 220 having a cartridge cap 226, the cartridge cap 226 also serving as a dispensing insert. Fig. 30a shows a double-walled lid 226 to be screwed onto the neck of the cartridge 220 during storage. The lid 226 includes a recessed portion 228, the recessed portion 228 extending into the cartridge neck 222, thereby limiting the amount of air trapped in the cartridge 220 after filling and securing the lid. The outer wall 230a of the lid 226 is contoured and lies flush with the outer wall of the cartridge at its open end. The inner wall 230b of the cartridge cover 226 has a threaded portion that engages a complementary threaded portion on the inner wall of the cartridge neck.

Fig. 30b shows the cartridge 220 fitted to the applicator head assembly 214 after the cap 226 has been removed. The assembled applicator still contains a large volume of air at the neck of the cartridge which must be vented before the applicator can dispense the dose of medicament. Figure 30c shows how the applicator can be filled for use by inserting the cartridge cap 226 (smaller circumference first) into the non-discharge end of the cartridge. Advancing the cap 226 into the rear end of the cartridge 220 pushes the cartridge plunger 221 further into the cartridge, thereby displacing residual air at the neck of the cartridge. The extent to which the filler insert/cap 226 can be inserted is limited by the shoulder portion 227 formed by the different outer cap diameters. Thus, the cap 226 can be inserted generally enough to vent all air from the assembled applicator. After filling, the cap/insert 226 may be removed from the rear end of the cartridge 220 and discarded, or left in place as desired.

Fig. 31a to 31c are perspective views of alternative hoods 370a, 370b, 370c for use with single nozzle applicators. In fig. 31a, the hood 370a shields the nozzle and the application face of the applicator, thereby keeping the applicator in a hygienic condition ready for use. The cover 370a includes tabs 371 that a user can press or pull on the tabs 371 when attaching or detaching the cover to or from the applicator. The cover 370a may have a projection (not shown) on its underside, adjacent the tab 371, for engagement in a corresponding recess in the applicator head to prevent the cover from otherwise disengaging.

The cover of fig. 31b has a similar profile to that of fig. 31a, except that this cover extends to cover the actuator pull rod 232 to prevent accidental actuation when the applicator is not in use, and also to protect the actuator pull rod from possible damage, such as might occur if the pull rod were to hang from any object.

The cover of fig. 31c does not conceal the actuator pull rod but instead includes a pair of opposed arms 375, 375', each terminating in a projection 376, 376', which projections 376, 376' wedge behind the pull rod when the arms are clamped around the pull rod 232 when the cover is mounted on the applicator. The wedges 376, 376' effectively prevent the actuator pull rod 232 from being pressed towards the applicator body or cartridge, thereby acting as a pull rod lock to prevent accidental actuation.

In fig. 32a to 32d, an applicator according to a further aspect of the invention is shown, namely comprising a dispensing head 514 of the type having a stop 582, the stop 582 being for displacing air and formulation from a cartridge nozzle 522 on the assembly. The retainer 582 is provided with a lip seal 584 around its insertion end to seal against the inner wall of the cartridge nozzle 522. The retainer 582 is double walled with a central bore 590 that houses an inlet valve 561 including a ball 630 and a spring 633. A suction tube or inner tube 592 extends from the valve seat 516 into the bore 590, and a vent 594 is provided through the inner wall of the bore 590 at its uppermost end, beyond the lowermost end of the inner tube 592. The vent 594 opens into a passage 596 in the form of a space in the U-shaped channel between the stop 582 and the tubular portion 602 of the manifold 600, providing a flow path for air and formulation up to the constricted threaded section 604, which constricted threaded section 604 prevents formulation flow while allowing air to pass through.

A chamber 610 is provided in the manifold 600 beyond the threaded section 604, and a wall 612 in the bobbin port 580 of the manifold seals against the upper end of the bobbin nozzle 522 so that air from the nozzle displaced by the stop 582 is eventually trapped in the chamber 610.

The dispensing head 514 of fig. 32 a-32 d further includes dispensing nozzles 540, and the manifold 600 also houses a pump chamber 550 similar to the pump assembly shown in fig. 26a and 26 b. The dispensing head 514 is shown fitted with a head cap 570, the head cap 570 having a protrusion 572, this protrusion 572 sealing the nozzle tip to prevent oxidation of the formulation that has been pumped to the nozzle when the dispenser is not in use.

Figures 33a to 33d illustrate the effect achieved by the stop 582 during assembly of the applicator of figures 32a to 32d when the applicator/dispenser head 514 is fitted into the cartridge nozzle 522. Beginning at fig. 33a, when the cartridge nozzle 522 is brought into alignment with the cartridge port 580 of the dispenser head 514, a lip seal 584 around the front end of the stop 582 seals against the inner wall of the nozzle 522 and the stop reaches the formulation 620 in the nozzle. As illustrated here, the cartridge 520 has been filled with the maximum fill level of formulation 620. When the cartridge nozzle 522 is further inserted into the cartridge port 580, as shown in fig. 33b, the formulation 620 is displaced by the stop 582, and the formulation 620 is forced upwardly through the central bore 590 of the stop 582. The diameter of the inner tube or straw 592 is limited such that the formulation 620 is forced around the tube 592 to a vent 594 at the upper end of the stopper bore 590 upstream of the inlet valve 561. Formulation 620 is forced through vent 594 into the space between stop 582 and surrounding manifold wall 612 until thread tightening section 604, which prevents further flow of formulation. As the stop 582 is advanced still further, as shown in fig. 33c, the backpressure created by the formulation 620 entering the constriction section 604 becomes greater than the pressure required to move the plunger 521 within the cartridge 520, with the result that the plunger 521 reverses direction along the body of the cartridge, thereby expanding the volume of the cartridge 520 containing the formulation 620 with which the stop 582 is displaced from the nozzle 522. To fully insert the stop 582, the cartridge 520 is then threaded onto the dispenser head 514 via the complementary threads 640, 642 surrounding the outer base of the nozzle wall and the manifold cartridge port 580. Once the stop 582 is fully inserted, as shown in fig. 33d, the wall 612 in the cartridge port 580 seals against the end of the cartridge nozzle 522 at its top edge, creating a sealing system. Displacement air is trapped in the chamber 610 at the end of the tightening section 604.

The path taken by the air and formulation displaced by the stop 582 is shown in more detail in figure 34. Arrows a and B show the path taken by air displaced by the stop 582 on the first assembly; the formulation will also be forced along this path, but only to the threaded section 604, at which point the passageway 596 or channel becomes minimal and the pressure necessary to push the formulation 620 further through the threaded section 604 becomes higher than the pressure necessary to push the plunger (not shown) in the cartridge 520 so that no more formulation 620 is delivered and the remaining formulation remains within the cartridge 520. In addition, the stopper 582 pushes the formulation 620 to the bottom of the inner tube 592, as indicated by arrow C. The assembled applicator/dispenser is now primed to the point that when the first dispensing operation occurs by squeezing the pull rod arm 532 to advance the piston 560 in the pump chamber 550, the formulation 620 will be immediately drawn up through the inner tube 592 so as to wet the ball 630 of the inlet valve 561.

Fig. 35 illustrates, in cross-section, a cartridge 520 having a cover 524 for the dispenser head 514 shown in fig. 32 and 33. The cartridge 520 has a plunger 521, the plunger 521 sealing against the inner cartridge wall and opening out at the base to provide stability when seated in an upright position (either alone or assembled with the applicator/dispenser head 514). The cartridge 520 has an elongated nozzle 522 that is slightly narrowed at its uppermost edge to facilitate assembly of the cartridge cover 524 for storage and insertion into the stopper 582 of the cartridge port 580 when mated to the head 514. The lid 524 has an H-section for reducing the risk of damage to the spout 522 in the event that the cartridge 520 is dropped, and has threads 644 for screwing onto complementary threads 642 around the base of the spout 522. The lower section of the lid 524 (which is hollow) does not interact with a one-way locking feature (not shown) on the cartridge 520 and therefore the lid 524 is easily removed by unscrewing.

A cartridge 520 (shown with the cap removed) is illustrated in perspective view in fig. 36 along with the applicator/dispenser head 514. The cartridge 520 has an outer ring 650 concentric with the nozzle 522, the outer ring 650 extending from the cartridge shoulder and being provided with four outwardly projecting engagement ribs 532, the engagement ribs 532 interacting with locking clips 528 on the head 514 when the cartridge 520 is screwed onto the head.

Fig. 37 is a cross-section through the assembled bobbin and head, showing the interaction between the engagement rib 532 of the bobbin 520 and the locking clip 528 on the bobbin port 580 of the head 514, the engagement rib 532 and locking clip 528 together providing a one-way lock. Specifically, when the bobbin 520 is threaded onto the head 514 in a counterclockwise direction, the rib 532 presses down on the clip 528 and against the clip 528, and when an attempt is made to unscrew the bobbin 520 by moving in a clockwise direction, the rib 532 simply abuts against the protruding edge of the clip 528 to prevent further unscrewing.

Many other variations are possible, and while several examples have been chosen to illustrate the invention, it will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the invention. In addition, the applicator may be used to apply medicaments for a wide variety of skin conditions affecting the scalp and other body areas, including, for example, dermatitis and eczema, as well as psoriasis. Combinations of the features described above, whether or not exemplified, are considered to be within the scope of the present invention. Thus, the foregoing descriptions of the embodiments according to the present invention are provided for illustration only, and not for the purpose of limiting the invention.

Claims (88)

1. A hand-held applicator for targeted self-administration of a semi-solid medicament directly to the scalp and other body areas, the applicator comprising:

an applicator head comprising an elongated dispensing nozzle for contacting the scalp and other areas of the body;

an applicator body for receiving a medicament reservoir;

a pump assembly comprising a pump chamber having an inlet for receiving medicament from the medicament reservoir and an outlet for discharging medicament to the dispensing nozzle on the applicator head; and

an actuator operable on the pump chamber for pumping a dose of medicament in the chamber through the outlet and dispensing a corresponding dose of medicament from the dispensing nozzle onto the scalp or other body area,

wherein the applicator head further comprises an application face for spreading the dispensed medicament over the body area to be treated.

2. A hand-held applicator for self-administering a semi-solid medicament directly to the scalp, the applicator comprising:

an applicator head comprising one or more elongate dispensing nozzles for passing through hair and contacting the scalp in the area to be treated;

an applicator body for receiving a medicament reservoir;

a pump assembly comprising at least one pump chamber having one inlet for receiving medicament from the medicament reservoir and one or more outlets for discharging medicament to the or each dispensing nozzle on the applicator head; and

an actuator operable on the or each pump chamber for pumping a dose of medicament in the chamber through the or each outlet and dispensing a respective dose of medicament from one or more of the dispensing nozzles onto the scalp,

wherein the applicator head and applicator body are fixed relative to one another in use so that movement of the nozzle away from the scalp or other body area during actuation can be avoided.

3. A hand-held applicator for self-administering a semi-solid medicament directly to the scalp, the applicator comprising:

an applicator head comprising one or more elongate dispensing nozzles for passing through hair and contacting the scalp in the area to be treated;

an applicator body for receiving a medicament reservoir;

a pump assembly comprising at least one pump chamber having one inlet for receiving medicament from the medicament reservoir and one or more outlets for discharging medicament to the or each dispensing nozzle on the applicator head; and

an actuator operable on the or each pump chamber for pumping a dose of medicament in the chamber through the or each outlet and dispensing a respective dose of medicament from one or more of the dispensing nozzles onto the scalp,

wherein the applicator head is replaceable on the applicator body, enabling the applicator to be changed from a single nozzle applicator to a multi-nozzle applicator and vice versa.

4. A hand-held applicator for self-administering a semi-solid medicament directly to the scalp, the applicator comprising:

an applicator head comprising a plurality of elongate dispensing nozzles for passing through hair and contacting the scalp in an area to be treated;

an applicator body for receiving a medicament reservoir;

a pump assembly comprising at least one pump chamber having one inlet for receiving medicament from the medicament reservoir and one or more outlets for discharging medicament to each dispensing nozzle on the applicator head;

an actuator operable on the or each pump chamber for pumping a predetermined dose of medicament from the chamber through the or each outlet and dispensing a respective dose of medicament from one or more of the dispensing nozzles onto the scalp; and

a nozzle selector mechanism adapted to permit dispensing of medicament from all nozzles when in a first selected mode, and permit dispensing of medicament from only a single nozzle when in a second selected mode.

5. The applicator of any one of claims 2 to 4, wherein the applicator head further comprises an application face for spreading the dispensed medicament over a body area, thereby enabling the applicator to serve the dual function of a scalp and body applicator.

6. The applicator of claim 1 or 5, wherein the application face is disposed adjacent a dispensing nozzle.

7. An applicator according to any preceding claim, comprising an airless delivery system whereby medicament in the applicator is substantially free of air contact.

8. An applicator according to any preceding claim, wherein the applicator body comprises a cartridge of medicament.

9. An applicator according to any preceding claim, further comprising a cartridge port for receiving a dispensing end of a cartridge containing medicament, whereby the cartridge port is in fluid communication with the or each inlet of a respective pump chamber of the pump assembly.

10. The applicator of claim 9, wherein the cartridge port comprises a sealing member for sealing against a neck of the cartridge to prevent leakage of medicament.

11. The applicator of claim 10, wherein the sealing member comprises a stopper for insertion in the cartridge neck to displace air from the cartridge, the stopper containing a central bore for permitting medicament to flow from the cartridge to the pump chamber via the inlet.

12. An applicator according to claim 10 or claim 11, wherein the cartridge port further comprises a cap for engaging with an outer wall of the cartridge neck to secure the sealing member relative to the neck.

13. An applicator according to any of claims 8 to 11, further comprising a priming insert for advancing a cartridge plunger at a non-dispensing end of the cartridge along the cartridge body so as to displace air from the cartridge and prime medicament in the applicator prior to its first use.

14. An applicator according to any preceding claim, wherein the applicator head, pump assembly and actuator together comprise a unitary head assembly for connection with a medicament cartridge comprising the applicator body.

15. An applicator according to claim 14, wherein the head assembly is provided with a one-way mechanism for preventing disengagement of the head assembly from the cartridge once the cartridge has been fitted onto the head assembly.

16. An applicator according to any preceding claim, wherein the or each dispensing nozzle projects at an oblique angle relative to the applicator body, and wherein more than one nozzle is provided, the nozzles extending parallel to one another.

17. An applicator according to claim 16, wherein the or each nozzle extends substantially perpendicularly from the inclined face of the applicator head.

18. An applicator according to claim 16, comprising a single nozzle and an application face for spreading the dispensed medicament over a body area, wherein the nozzle and application face together constitute a substantially continuous surface of the applicator.

19. An applicator according to any preceding claim, wherein the or each nozzle is tapered, preferably in cross-section towards the nozzle tip, so as to enhance penetration of hair during scalp application.

20. An applicator according to any one of claims 1 to 17, having a plurality of, preferably three, spaced nozzles.

21. An applicator according to claim 20, wherein the nozzles are spaced apart by at least 20mm and less than 40mm, preferably between about 25mm and 35mm, more preferably 27mm to 33 mm.

22. The applicator of claim 21, wherein the tips of the nozzles are each placed on the same plane for enabling all nozzle tips to rest against a user's scalp at the same time.

23. An applicator according to any preceding claim, wherein the or each nozzle comprises a nozzle stem of substantially rigid material and a nozzle tip of material less stiff than the nozzle stem material, and preferably comprises a resilient elastomeric material.

24. An applicator according to claim 23, wherein the or each nozzle stem terminates in a terminal port and the or each nozzle tip has one or more side ports, preferably a pair of opposed side ports, in fluid communication with the stem terminal port and from which medicament can be dispensed.

25. The applicator of any one of claims 1 to 17 and 19 to 24, having a plurality of spaced nozzles, and further comprising a nozzle selector mechanism adapted to permit dispensing of medicament from all nozzles when in a first selected mode, and to permit dispensing of medicament from only a single nozzle when in a second selected mode.

26. The applicator of claim 25, wherein the nozzle selector mechanism is further adapted to prevent dispensing of medicament from all nozzles when in a third selected mode.

27. The applicator of claim 25 or 26, wherein the single nozzle is longer than the other nozzles and the nozzle tips of all nozzles are placed in the same plane for enabling all nozzle tips to rest against a user's scalp simultaneously when the nozzle selector mechanism is in the first selected mode and for enabling only the single nozzle to rest against the scalp by altering the angle at which the applicator body is held when the selector mechanism is in the second selected mode.

28. The applicator of any one of the preceding claims, further comprising an inlet valve for sealing the inlet against the medicament reservoir under positive pressure in the pump chamber and opening the inlet under negative pressure in the pump chamber to permit medicament to flow from the reservoir into the chamber.

29. An applicator according to any preceding claim, further comprising one or more outlet valves for sealing the outlet relative to the or each pump chamber under negative pressure in the pump chamber and opening the outlet under positive pressure within the pump chamber to permit medicament to flow from the chamber to the nozzle.

30. An applicator according to claim 28 or claim 29, wherein the or each inlet valve or the or each outlet valve or both comprises an integral valve moulding having a valve member for closing the inlet or outlet, an anchoring portion for securing the moulding relative to the inlet or outlet, and a spring portion between the valve member and anchoring portion for urging the valve member against the inlet or outlet to close the valve.

31. An applicator according to claim 29 or claim 30, wherein the or each outlet valve comprises resilient material permitting outward deformation away from the respective outlet of the outlet valve during application of the expelling force on the pump chamber.

32. An applicator according to any preceding claim, wherein the or each pump chamber is a collapsible chamber, preferably a rolling diaphragm chamber.

33. An applicator according to claim 32, wherein the or each collapsible chamber has an outer casing for guiding the side walls of the chamber when the actuator is operated.

34. The applicator of claim 33, wherein the outer casing has an aperture aligned with a central longitudinal axis of the chamber, and the pump assembly further comprises a chamber pin extending through the aperture such that one end of the pin is in contact with an end wall of the chamber and, upon operation of the actuator, the other end is urged by the actuator, forcing the end wall of the chamber inwardly so as to contract the chamber.

35. An applicator according to any one of claims 1 to 31, wherein the or each pump chamber comprises a cylinder.

36. The applicator of claim 35, wherein a longitudinal axis of the cylinder is substantially perpendicular to a longitudinal axis of the applicator body.

37. An applicator according to any preceding claim, wherein the actuator comprises a plunger, preferably a plunger body and an actuating rod, for displacing medicament from the or each pump chamber, and a pull rod arm rotatable about a fulcrum for advancing the plunger.

38. An applicator according to any one of claims 1 to 17 and 19 to 37, wherein the applicator head has three nozzles and the pump assembly comprises two pump chambers, one chamber having an outlet for dispensing medicament to one of the nozzles and the other chamber having an outlet for dispensing medicament to the remaining two nozzles, the applicator further comprising a nozzle selector mechanism for selectively expelling medicament from the two chambers in a first mode of operation and from only the one chamber in a second mode of operation.

39. The applicator of claim 38, wherein the volume of the one chamber is substantially half the volume of the other chamber, such that the volume of medicament dispensed in the first mode of operation is approximately three times the volume of medicament dispensed from the single nozzle in the second mode of operation.

40. The applicator of claim 38 or 39, wherein two pump chambers comprise a rolling diaphragm chamber and an associated casing, the end wall of each chamber being joined to a respective chamber pin which extends through a central aperture in each casing, and wherein the actuator comprises a plunger which is rotatable about a longitudinal axis parallel to the longitudinal axis of the pump chamber and which, when actuated, is selectively operable on one or both chamber pins depending on the rotational position.

41. The applicator of any one of the preceding claims, wherein the actuator comprises a rotatable plunger, and the applicator further comprises a dial for rotating the plunger, whereby the plunger may be rotated to a single nozzle dispensing position, wherein actuation of the plunger causes medicament to be expelled from one pump chamber, and if the applicator contains two or more pump chambers, the plunger may also be rotated to a multi-nozzle dispensing position, wherein actuation causes expulsion from all pump chambers.

42. The applicator of claim 41, wherein the plunger is rotatable by the dial to a locked position wherein actuation of the plunger does not cause medicament to be expelled.

43. The applicator of claim 41 or 42, wherein the rotatable plunger comprises a plunger body having a positive actuation face and an actuator rod of asymmetric cross-section protruding from a rear of the plunger body, and the dial has a central aperture of corresponding cross-section for receiving the actuator rod, whereby rotation of the dial causes rotation of the plunger.

44. The applicator of claim 43, comprising two or more pump chambers having chamber pins extending therefrom, and wherein the positive actuation face of the plunger body is provided with three or more apertures, the apertures being spaced apart in such a way that when rotated to a first plunger position the plunger face advances all chamber pins upon actuation of the actuator rod, thereby expelling medicament from all pump chambers, when rotated to a second plunger position the plunger face advances only the chamber pin associated with the pump chamber, the chamber pin is expelled to a single nozzle (the other chamber pin is received in an aperture such that the other chamber pin is not advanced), and when rotated to a third plunger position the plunger face does not contact the chamber pin (all chamber pins are received in respective apertures), such that no medicament is expelled when actuated.

45. The applicator of claim 44, further comprising an insert interposed between the dial and plunger body, the insert having a plurality of internal tabs that act as keys that cooperate with external tabs on the plunger body to permit reciprocating (back and forth) movement of the plunger body only when the plunger body is in a pumping (single and multi-nozzle dispensing) or locked position.

46. An applicator according to any preceding claim, further comprising a removable cover for protecting the application face and sealing the or each nozzle when the applicator is not in use.

47. The applicator of claim 46, wherein the hood further comprises an actuator lock for preventing operation of the actuator when the hood is assembled.

48. A system for dispensing a semi-solid formulation, comprising:

a dispensing head; and

a cartridge for the formulation having a dispensing nozzle for engagement with the dispensing head and a plunger for advancing along the cartridge as the formulation is dispensed,

wherein the dispensing head comprises a cartridge port comprising a stopper for insertion therein and sealing against the cartridge nozzle when the cartridge is engaged with the cartridge port, the stopper having a bore therethrough to permit flow of formulation from the cartridge to the dispensing head via an inlet valve during a dispensing operation, and

wherein the stopper bore is provided with a vent and the dispenser head contains a passageway having a constricted section in fluid communication with the vent whereby formulation displaced by the stopper on insertion into the cartridge nozzle is forced into the bore and out through the vent into the constricted passageway whereupon the pressure necessary to force formulation further into the passageway becomes greater than the pressure necessary to move the cartridge plunger and any further displaced formulation is accommodated in the cartridge by reverse movement of the plunger.

49. A dispensing system according to claim 48, wherein the stopper has a length such that when fully inserted within the cartridge nozzle, a leading end of the stopper projects beyond a minimum fill level of the cartridge, and preferably the stopper extends substantially along the full length of the cartridge nozzle when fully inserted.

50. Dispensing system according to claim 48 or 49, wherein the volume of the passage, at least the portion of the passage preceding (upstream of) the constriction section, is such as to contain a volume of formulation which is less than the total volume of formulation to be displaced by the stopper if the cartridge is filled only to the minimum filling level.

51. The dispensing system of any one of claims 48 to 50, wherein the inlet valve is provided within the stopper bore.

52. The dispensing system of any one of claims 48 to 51, wherein the inlet valve comprises an inclined valve seat projecting from an internal bore wall into the bore and a valve closure member for sealing against the valve seat.

53. The dispensing system of claim 52, wherein the valve closure member comprises a spring-loaded ball.

54. The dispensing system of any one of claims 51 to 53, wherein the vent is located adjacent the inlet valve for permitting the bore to be substantially filled with formulation upstream of the inlet valve when the stopper is advanced into the cartridge nozzle.

55. The dispensing system according to any one of claims 48 to 54, wherein the bore contains an inner tube of smaller diameter and length than the bore extending from the inlet valve, the inner tube preferably extending from the valve seat into the bore such that once the dispenser head and cartridge are assembled, formulation displaced by the stopper flows along the bore all the way to the inner tube, whereupon it is forced around the exterior of the inner tube to the vent and beyond the passage of the vent.

56. The dispensing system of claim 55, wherein the inner tube extends into the bore beyond the vent opening but terminates substantially short of an end of the stopper.

57. The dispensing system of claim 56, wherein the volume of the inner tube is such that after assembly of the cartridge and dispenser head, a first actuation of the dispenser causes any residual air to be purged from the inner tube and causes formulation to be drawn into the inner tube so as to wet the inlet valve.

58. The dispensing system of any one of claims 48 to 57, wherein the air and formulation are discharged to a first passage section, permitting free flow of discharged air and formulation, followed by a second passage section that is constricted relative to the first section, permitting free flow of air but providing resistance to flow of formulation.

59. The dispensing system of claim 58, wherein the dispensing head further comprises a manifold, and wherein the manifold and stopper together define the cartridge port.

60. The distribution system of claim 59, wherein the first passage section comprises a space, such as a continuous space or a plurality of channels, between the stopper and manifold, and the second passage section comprises one or more channels of smaller cross-section than the first section also between the stopper and manifold.

61. The dispensing system of claim 60, wherein the second passage section comprises a complementary threaded section between the stopper and manifold.

62. The dispensing system according to any one of claims 48 to 61, wherein the stopper comprises a double wall component and wherein an inwardly directed surface of the inner wall provides the central bore and an outwardly directed surface of the outer wall provides a seal for sealing against the inner wall of the cartridge nozzle when the dispenser head and cartridge are assembled.

63. The dispensing system in accordance with claim 62 in which said outwardly directed surface of said outer stopper wall includes a lip seal or the like.

64. The dispensing system in accordance with claim 62 or 63 in which the gap between the inner and outer stopper walls provides a substantially U-shaped cylindrical channel closed at the front end for forcing formulation into the central bore when the stopper is inserted into the cartridge nozzle, and in which the vent is provided through the inner stopper wall of the stopper whereby air and formulation displaced as the stopper is advanced in the cartridge nozzle when the system is assembled is forced first along the bore towards the vent and then out of the vent of the passageway.

65. The dispensing system of any one of claims 62 to 64, wherein the channel of the double wall retainer is adapted to receive and accommodate a tubular portion of the dispenser head manifold, and the tubular portion and cylindrical channel are dimensioned relative to one another, for example so as to form the passageway therebetween through which air and agent are forced through the vent.

66. The dispensing system in accordance with claim 65 in which said passageway follows a path first downwardly along the outwardly facing surface of said inner retainer wall, along the base of said channel, and upwardly along the inwardly facing surface of said outer retainer wall.

67. The dispensing system of claim 66, wherein the tightened section of the passage is created by complementary threaded sections on an inwardly directed face of the external stopper wall and an outwardly directed face of the manifold tubular portion, preferably adjacent an open end of the U-shaped channel.

68. The dispensing system according to any one of claims 48 to 67, wherein the dispensing head further comprises a chamber in which displaced air can be contained, the chamber preferably being downstream of the constricted passage.

69. The dispensing system according to claim 68, wherein the chamber is sealed by the cartridge nozzle when the cartridge is assembled with the dispensing head.

70. The dispensing system of any one of claims 48 to 69, wherein the manifold further comprises an attachment feature for securing the cartridge to the dispensing head.

71. The dispensing system in accordance with any one of claims 48 to 70 in which the dispensing head and cartridge are provided with a one-way locking mechanism which permits the dispenser head and cartridge to be assembled but prevents separation once assembled.

72. The dispensing system of claim 71, wherein the manifold includes one or more, preferably opposed, pair of head locking clips, and the cartridge includes a plurality of engagement ribs, and wherein the clips press against engagement ribs when the cartridge is screwed onto the dispenser head, but act as a stop for the ribs when an attempt is made to unscrew the assembly.

73. The dispensing system of any one of claims 48 to 72, wherein the dispensing head further comprises a pump assembly comprising a pump chamber and an outlet through which the formulation is dispensed, the dispensing head also including an actuator operable on the pump chamber for pumping formulation from the cartridge into the chamber via the inlet and out through the outlet.

74. The dispensing system according to claim 73, wherein the dispensing head further comprises one or more elongated nozzles in fluid communication with the outlet for penetrating hair and applying an agent to the scalp or other body area.

75. The dispensing system of claim 74, wherein the system comprises a hand-held applicator of any one of claims 1 to 47.

76. A cartridge for storing a medicament reservoir, the cartridge having a first dispensing end adapted to fit to a cartridge port of an applicator or dispensing head according to any preceding claim.

77. The cartridge according to claim 76, wherein the cartridge includes a locking structure for interlocking with a complementary structure on the applicator or dispensing head, whereby the locking structure cooperates to permit assembly and prevent disassembly.

78. The cartridge according to claim 77, wherein the locking structure comprises a plurality of engagement ribs on a collar surrounding the nozzle neck of the cartridge for engagement with complementary locking clips on the applicator or dispensing head.

79. The cartridge according to any one of claims 76 to 78, wherein the cartridge neck is adapted to receive and form a seal with a stopper of an applicator head assembly or manifold of a dispenser head so as to form an airtight connection upon displacement of air from the cartridge neck by insertion of the stopper.

80. The cartridge according to claim 79, wherein the inner wall of the cartridge neck is tapered at its open end, the tapered section providing a sealing surface for a manifold seal wall.

81. The cartridge according to any one of claims 76 to 81, wherein the cartridge neck is double walled to provide a secondary chamber for receiving any medicament forced away from the cartridge from between the neck and the stopper after insertion of the stopper.

82. The cartridge according to any one of claims 76 to 81 comprising a tube or the like for containing medicament and a plunger in sealing contact with an inner tube wall, the plunger being adapted to be urged upwardly along the tube wall under negative pressure generated when medicament is expelled from the or each pump chamber of the applicator.

83. The cartridge according to claim 82, further comprising a cartridge cover for sealing the dispensing end of the cartridge prior to use, and wherein the cartridge cover combines the functions of a priming insert for insertion at a non-dispensing end of the cartridge for rearward advancement of the plunger and priming of the applicator for use.

84. The cartridge according to any one of claims 76 to 83, further provided with an end cap at its non-dispensing end for sealing the open end of the applicator body when the cartridge is to be inserted into the applicator body.

85. An applicator according to any of claims 1 to 47, containing a cartridge of medicament according to any of claims 76 to 84.

86. An applicator system for applying medicament to a patient, the applicator system characterised by an applicator according to any one of claims 1 to 47 and a cartridge according to any one of claims 76 to 85.

87. A method of delivering a semi-solid medicament to the scalp or other body region, the method comprising: (i) loading an applicator body of an applicator with the medicament, the applicator further comprising an applicator head fixed relative to the applicator body and having one or more elongate dispensing nozzles for contacting scalp and other body areas, a pump assembly comprising at least one pump chamber having one inlet for receiving medicament from the applicator body and one or more outlets for discharging medicament to the or each dispensing nozzle, and an actuator operable on the or each pump chamber for pumping a dose of medicament in the chamber through the or each outlet, (ii) priming the applicator to transfer medicament from the applicator body to the pump chamber and the or each nozzle, and (iii) thereafter delivering the medicament by contacting the or each nozzle with the scalp or other body area, and (iv) operating the actuator to pump a dose of medicament from the chamber through the nozzle and to expel a dose of medicament from the nozzle onto the scalp or other body area.

88. The method of claim 87, wherein the loading step comprises inserting a dispensing end of a cartridge containing medicament into a cartridge port on the applicator, the cartridge port being in fluid communication with the inlet of the pump chamber.