HK1178822B - Novel bandage including agglomerates of particles suitable for rapidly gelling or solubilising - Google Patents

Description

The present invention relates to a new re-placing bandage comprising an adhesive hydrocolloidal mass for the treatment of wounds such as effusion wounds, burns, superficial, deep, chronic or acute dermoepidermal lesions and in particular for the treatment of the bulb.

Hydrocolloid-containing dressings have been known for more than 20 years. They consist of a support on which an adhesive mass containing hydrocolloids is placed. Examples include products marketed under the names Algoplaque® by URGO Laboratories and Comfeel® by Coloplast. Dressings containing an adhesive mass containing hydrocolloids, specifically for the treatment of the ampoule, are also known and marketed, for example, under the names Urgo Ampoules® by URGO Laboratories and Compeed® by Johnson & Johnson.

To allow for good absorption of exudate from the wound, these dressings contain relatively large amounts (in the range of 20 to 50% by mass) of hydrocolloids.

The adhesive mass of these known dressings is usually a continuous hydrophobic phase in which a discontinuous phase of hydrocolloid particles is dispersed to absorb exudate from the wound.

The absorption of exudate by hydrocolloids causes the adhesive to gels, which allows painless removal of the bandage from the wound after use.

To ensure that their absorption capacity and cohesion are maintained over time when removed, these dressings have a high initial adhesive power.

To increase the adhesive power of these dressings, work has been done: The Commission has therefore decided to initiate the procedure laid down in Article 85 (2) of the Treaty.

Such dressings and their compositions are well known and described, for example, in documents EP 264 299, EP 503 029, EP 1 020 198 and FR 2 495 473.

However, because of their high adhesive power, these bandages cannot be easily repositioned when they are placed on the patient's skin, as removal of these bandages is very painful as the bandage adheres to the wound or bulb until it has absorbed exudate, which may require a relatively long time of about 15 minutes or more.

However, repositioning the bandage when it is put in place is very often necessary, for example when the surface of the body on which the bandage is to be applied is not flat, and this problem is well known to healthcare professionals.

In addition, these dressings are all the more difficult to install because they are generally very thin and, in the case of dressings for the treatment of the bulb, small in size and must be placed in difficult to access places: toes, soles, heels, etc.

Many users have already faced this repositioning problem, especially in the case of bandages intended for the treatment of the bulb which are also desirable for reasons of discretion and aesthetics, for example to avoid the formation of creases or to hide behind the shoelace.

Although many applicator systems have been developed over the last twenty years to facilitate the application of these dressings, these systems do not, however, allow a satisfactory solution to the problem of repositioning, and in particular there is no ideal solution to the problem of painless removal of an adhesive bandage immediately after first placement.

Document EP 0 621 042 describes a hydrocolloidal dressing whose adhesive layer consists of a three-dimensional mesh consisting of polymer filaments coated with an adhesive material insoluble in water and connected to each other inside which hydrocolloids are dispersed.

The problem of painless removal of the bandage immediately after application, in order to allow its repositioning, while maintaining its adhesion, cohesion and absorption properties over time, is not addressed in any way in this previous document, nor is the use of specific soluble and soluble polymers.

In these circumstances, the present invention aims to solve the new technical problem of providing a newly designed adhesive hydrocolloidal bandage which can be removed without pain immediately after application and repositioned once or several times, while retaining its adhesion, cohesion and absorption properties over time.

It was discovered, and this is the basis of the present invention, that it was possible to solve this technical problem in a relatively simple and industrially usable manner by modifying the skin-contact surface of a traditional hydrocolloidal adhesive dressing by depositing preconstituted particle aggregates which can dissolve or gelle when in contact with wound exudates very considerably completely and in a short time, preferably less than 10 seconds, and preferably even less than 1 second.

Thus, according to the first aspect, the present invention concerns a dressing comprising an adhesive mass comprising hydrocolloids characterized by the fact that it contains, on at least one part of the surface of the adhesive mass intended to come into contact with the wound in the position of use, a plurality of aggregates consisting of interconnected particles, preferably in a multilayer configuration, the said particles being at least 90% and preferably at least 95% of one or more of the following: selected from polysaccharides and in particular starch, modified starches, maltodextrin, gum, including gum arabic,xanthan gum or acacia gum, pullulan, dextrans, cellulose, cellulosic derivatives such as in particular methylcellulose, hydroxypropylmethylcellulose, hydroxypropylcellulose, hydroxyethylcellulose, sugars, pectin, alginates, carrageenans, agar-agar proteins and in particular gelatine, albumin, collagen and casein; super-absorbent synthetic polymers and in particular polyacrylates; synthetic polymers and in particular polyvinyl alcohol; The stages of solubilization or gelling should be less than 10 seconds and preferably less than 1 second when in contact with wound exudates.

As is understood, by rapidly dissolving or gelling in contact with the exudate of the wound, the above-mentioned particulate aggregates will form an intermediate non-adhesive layer immediately (a few seconds at most) after the first placement of the dressing, thus allowing, if necessary, the dressing to be removed from the wound without pain and repositioned.

It was found that despite the presence of these water-soluble or gellifiable particle aggregates, the dressing retains the same adhesion profile at withdrawal, the same absorption properties as a dressing of the same composition but not including these aggregates. In particular, no migration of exudates beyond or around the part of the surface of the adhesive mass covered by the layer formed after gelling or solubilising of the aggregates was observed with these new dressings which could have altered the adhesive properties or the absorption and cohesion properties of the dressing by creating an absorption differential between these two areas.

Depending on the particular characteristic, these aggregates may contain particles of active substances which will be rapidly released and which will facilitate the healing of the blister or wound.

The bandage according to the present invention can be easily obtained by simply depositing preformed particle aggregates on the wound contact surface of an adhesive bandage containing hydrocolloids.

The adhesives containing hydrocolloids which may be used for the manufacture of the bandage according to the invention are those which are normally used by the artisan for the manufacture of hydrocolloid adhesive bandages.

In general, the adhesive masses of the dressings of the invention have an adhesive strength of at least 150 cN/cm, and preferably between 200 cN/cm and 8 N/cm measured on a steel plate according to European standard EN 1939 (90° measurement, 100 mm/min speed).

In general, these adhesives will consist of an elastomer matrix containing hydrocolloidal particles and one or more compounds intended to give adhesive properties to the said mass known as tactifiants .

elastomeric matrix means a composition comprising one (or more) elastomers selected from the poly-styrene-olefin-styrene sequence copolymers, the olefin sequences of which may consist of isoprene, butadiene, ethylene-butylene, ethylene-propylene units and their mixtures.

The present invention prefers poly (styrene-isoprene-styrene) triblocal copolymers (abbreviated: poly (SIS)) and mixtures of poly (SIS) triblocal copolymers and poly (SIS) diblocal copolymers, and in particular poly (SIS) containing between 14 and 52% styrene and preferably between 14 and 30% by weight in relation to the weight of the said poly (SIS).

Such products are well known to the art world, for example, they are marketed by Kraton under the name KRATON®D or by Dexco Polymers LP under the name VECTOR®.

The preferred poly (SIS) tribloid copolymers include in particular products marketed under the names KRATON®D-1111CS, KRATON®D-1107 or KRATON®1161, VECTOR®4114 and VECTOR®4113.

Poly (styre-butadiene-styrene) tribloid copolymers may also be used in the context of the invention.

These poly (styrene-butadiene-styrene) copolymers include the product marketed as KRATON®D-1102 by Kraton.

The elasmometers forming the elastomer matrix shall preferably be present in the adhesive mass of the dressings according to the invention in an amount of 10 to 30% by weight and preferably 15 to 25% by weight of the total adhesive mass.

Generally, the above-mentioned elastomer matrix incorporates one (or more) hydrocolloids.

hydrocolloid here means any compound usually used by the artisan for its ability to absorb hydrophilic liquids such as water, physiological serum or exudates from a wound.

Err1:Expecting ',' delimiter: line 1 column 489 (char 488)

It should be noted that these compounds are present in the elastomeric mass and although they may gell upon contact with the exudate, their eventual gelling is likely to occur only after a relatively long time, up to several hours, so that these compounds are not likely to solve the problem of repositioning the bandage.

The hydrocolloids of choice for the purpose of the present invention are the alkaline metal salts of carboxymethylcellulose, and in particular sodium carboxymethylcellulose.

The amount of hydrocolloids incorporated in the elastomer matrix will be adjusted according to the desired absorption level.

In the present invention, a quantity of hydrocolloids (which are preferably between 20 and 50% by weight of the total adhesive mass) is used if an absorbent bandage of the type described in EP 1 061 965, EP 1 165 717 and EP 0 927 051 is to be made.

Err1:Expecting ',' delimiter: line 1 column 559 (char 558)

In general, one or more tactifiers may be used which are incorporated into the hydrocolloidal mass in a large proportion of the order of 1 to 70% by weight relative to the total weight of the adhesive mass, which will be determined according to the nature and relative proportion of the other constituents of the latter, in order to obtain the desired adhesive power for the final composition.

Preferably, the tactifying product (s) will account for 10 to 40% by weight of the total hydrocolloid mass.

The tactifying products which may be used in the present invention may be selected from tactifying resins, low molecular weight polyisobutylene, low molecular weight polybutene or mixtures thereof.

The tackifying resins which may be used according to the invention include modified polyterpene or terpene resins, rosin resins, hydrocarbon resins, cyclic, aromatic and aliphatic resin mixtures, etc., or mixtures thereof.

Such products are marketed as: by GOODYEAR under the name WINGTACK®, such as in particular the synthetic resin formed from C5/C9 copolymers (WINGTACK® 86) or the resin based on synthetic polyterpene (WINGTACK® 10); or by HERCULES under the name KRISTALEX®, such as in particular the resin based on alpha-methylstyrene (KRISTALEX® 3085).

These adhesive resins may be used alone or in combination with other adhesive resins, preferably in a proportion of 20 to 50% by weight, and in particular 25 to 35% by weight, in relation to the total weight of the adhesive mass.

The low molecular weight polybutenes that may be used according to the invention include, for example, products marketed by BP CHIMIE under the name NAPVIS® and in particular the product marketed under the name NAPVIS® 10.

These polybutenes may be used alone or in combination with other tactifiers, preferably in a proportion of 5 to 30% by weight, and in particular of 8 to 15% by weight, in relation to the total weight of the adhesive mass.

Low molecular weight polyisobutylene that can be used according to the invention includes polyisobutylene with a molecular weight of 40 000 to 80 000 daltons, such as products marketed by BASF under the name OPPANOL® and in particular products marketed under the names OPPANOL®B12 and OPPANOL®B15.

These polyisobutylene may be used alone or in combination with other tactifiers, preferably in a proportion of 5 to 30% by weight, and in particular of 8 to 15% by weight, in relation to the total weight of the adhesive.

Various additional compounds may be added to the elastomer matrix containing the above tachycinnate and hydrocolloidal compounds to obtain hydrocolloidal adhesive masses with optimized elasticity, adhesion, time stability and cohesion properties.

Such compounds are for example stabilisers, such as antioxidants, plasticizers, such as polybutenes or plasticizing oils, or cohesion enhancers, such as butyl rubbers or high molecular weight polyisobutylene.

High molecular weight polyisobutylene that can be used according to the invention to improve adhesive mass cohesion include polyisobutylene with a molecular weight of 400 000 to 2 000 000 daltons, such as products marketed by BASF under the names Oppanol®B12 SFN or Oppanol®B30 SF.

These high-molecular-weight polyisobutylene may be used alone or in a mixture, preferably in a proportion of 2 to 20% by weight, and in particular 5 to 15% by weight, in relation to the total weight of the adhesive mass.

Stabilizer means any compound capable of providing stability to oxygen (antioxidant), heat, ozone and ultraviolet radiation of compounds used in the formulation of adhesive hydrocolloidal masses, in particular tachycinnate resins and sequence copolymers.

The antioxidant compounds that may be used according to the invention include phenolic antioxidants, such as products marketed by CIBA-GEIGY under the names IRGANOX®1010, IRGANOX®565 and IRGANOX®1076, and sulphuric antioxidants, such as zinc dibutyldiothyocarbamate marketed by AKZO under the name PERKACIT®ZDBC.

These compounds may be used alone or in combination, preferably in a ratio of 0 to 2% by weight, and in particular between 0.1 and 0.6% by weight, in relation to the total hydrocolloid mass.

The combination of IRGANOX®1010 and PERKACIT®ZDBC is preferred for the present invention.

The plasticizing compounds which may be used in accordance with the invention include plasticizers commonly used by the artisanal public for the preparation of hydrocolloidal adhesive masses and in particular polybutenes, such as products marketed by BP CHEMICALS under the name NAPVIS® 10, plasticizing oils and phthalate derivatives such as diocylphthalate.

The use of plasticizing oils is particularly preferred in the present invention.

plasticizing oil refers to mineral or vegetable oils commonly used by artists to plasticize the styrene-olefin-styrene-type sequential copolymers used in the composition of hydrocolloidal adhesives.

These mineral oils are generally composed of mixtures in varying proportions of paraffinic, naphthenic or aromatic compounds.

The plasticising oils which may be used in accordance with the invention include the products marketed by SHELL under the names ONDINA® and RISELLA® which are composed of mixtures based on naphthenic and paraffin compounds or under the name CATENEX® which are composed of mixtures based on naphthenic, aromatic and paraffin compounds.

The mineral plasticizing oil marketed as ONDINA®68 will be used in preference for the present invention.

These plasticizers may be used alone or in combination, preferably in a proportion of 5 to 20% by weight, and in particular 7 to 15% by weight, in relation to the total hydrocolloid mass.

The hydrocolloidal adhesive mass of dressings according to the invention may also contain one or more surfactants in an amount of 10% or less by weight, preferably 5% or less by weight, relative to the total hydrocolloidal mass.

A surfactant preferred in the present invention is the compound marketed as AcResin®.

Another surfactant preferred in the present invention is polysorbate 80, as for example the product marketed by SEPPIC under the name MONTANOX® 80.

For the purposes of this specification, the expression particle agglomerate means a set of small particles, i.e. having an average dimension between 500 nm and 1000 μm, preferably between 1 μm and 500 μm, bound together, preferably in a multilayered arrangement, e.g. in the shape of a raspberry.

Each agglomerate is generally of an average size of 5 to 2 000 μm and will therefore consist of approximately 10 to 10 000 particles, preferably about 100 to 1000 particles.

Such particle aggregates can be prepared, as a matter of course, by wet granulation processes, particularly by spray drying or in a fluidized air bed, generally using water or an aqueous mixture as a binder.

In general, the particles forming the aggregates are composed mainly, i.e. at least 90%, and preferably at least 95%, of a material selected from polysaccharides, proteins and synthetic polymers, and capable of solubilizing or gelling in less than 10 seconds and preferably in less than 1 second in contact with wound exudates.

The expression material capable of solubilizing means any material capable of dissolving in the exudate of the wound to form a homogeneous solution.

The term gelling material means any material capable of forming a gel on contact with wound exudates, i.e. a substance with a viscosity higher than that of water, e.g. greater than 10-3 Pa and preferably greater than 10-2 Pa.

Polysaccharides which may be used according to the invention include starch, modified starches, maltodextrin, gum such as gum arabic, xanthan gum or acacia gum, pullulan, dextrans, cellulose, cellulosic derivatives such as methylcellulose, hydroxypropylmethylcellulose, hydroxypropylcellulose, hydroxyethylcellulose, sugars, pectin, alginates, carraghenan, agar-agar.

Excellent results were obtained using maltodextrin particles which is therefore a preferred material for the implementation of the invention.

Proteins that may be used according to the invention include gelatin, albumin, collagen and casein.

The synthetic polymers which may be used according to the invention include superabsorbent polymers, such as polyacrylates, and water-soluble synthetic polymers, such as polyvinyl alcohol.

The agglomerates used in the present invention may be made of particles of different nature, depending on the degree of solubility, mechanical strength or temperature resistance desired.

Depending on a particular embodiment of the invention, the agglomerates contain one (or more) active substances.

Where more than one active substance is used, these may be incorporated either individually in separate agglomerates or as a mixture within the same agglomerate.

The active substances that may be used in the present invention may be selected from antifungals, antimicrobials or antibacterials such as sulfadiazine argentin, pH regulators, healing accelerators such as hyaluronic acid, vitamins, moisturizers, trace elements, local anaesthetics, odor trappers, menthol, methyl salicylate, hormones, anti-inflammatories and mixtures thereof.

A preferred active substance in the context of the invention is hyaluronic acid.

The agglomerates of the invention are arranged, whether uniformly or not, on the surface of the hydrocolloidal adhesive mass intended to come into contact with the wound, i.e. these agglomerates will not be present inside the hydrocolloidal adhesive mass.

In general, the aggregates will cover between 5% and 90% and preferably between 10% and 60% of the surface of the adhesive mass coming into contact with the wound, depending on the intended application, so that the surface coverage of the adhesive mass coming into contact with the wound will be in the range of 10% to 50% for a bandage for the treatment of the bulb and in the range of 20% to 70% for a bandage for the treatment of a scar or ulcer.

These aggregates may be incorporated into the bonding according to the invention by any process which allows them to be deposited on the surface of the hydrocolloidal adhesive.

For example, this operation can be carried out advantageously by spraying the agglomerates on the surface of the hydrocolloidal adhesive mass by means of a powder dispenser known to the professional.

According to a preferred embodiment of the invention, the preformed aggregates will be arranged only at the level of the area of the dressing intended to come into contact with the area of the wound to be treated.

For example, the agglomerates may be deposited at the level of the zones intended to form the central part of the dressings or distributed evenly or not evenly on the surface of these zones.

The agglomerates may be deposited in any geometric shape, such as a square, rectangular, oval or striped shape, by means of a stencil to obtain the desired shape.

The amount of aggregates deposited can vary widely and will generally be between 5 and 500 grams per square metre of dressing, preferably between 10 and 150 g/m2.

The bandages of the invention may be of different types but preferably include a support.

The adhesive mass bearing the aggregates may be assembled on a support of the type used in dressings marketed by Laboratoires Urgo under the name Algoplaque®, or by Convatec under the name Duoderm®, or by Coloplast under the name Comfeel®.

In general, the choice of support will be made according to the required properties (sealing, elasticity, etc.) in the desired application.

Thus, the bandage according to the invention may include a support such as a film consisting of one or more layers and of a thickness varying from 5 to 150 μm; a nonwoven or foam with a thickness of 10 to 500 μm on which the hydrocolloidal adhesive mass has been coated, continuously or non-continuously.

These supports made of synthetic or natural materials are well known to the artistic man.

The foam media used in the present invention include, for example, polyethylene, polyurethane and PVC foams.

The nonwoven media used in the present invention include nonwoven materials of polypropylene, polyethylene, polyurethane, polyamide, or polyester, for example.

In the present invention, the preferred medium is film, and in particular polyurethane films, such as films marketed by Smith and Nephew under the name LASSO® made from polyurethane marketed by BF GOODRICH under the name ESTANE®; low-density polyethylene films, such as films marketed by SOPAL; films based on thermoplastic polyether-polyester copolymer, such as products marketed by DUPONT DE NEMOURS under the name Hytrel®; or complex films combining polyurethane film and a nonwovens.

According to one embodiment of the invention, the dressing may have an absorbent layer placed between the support and the adhesive hydrocolloidal mass. This absorbent layer may be made of any type of absorbent material such as foam (such as polyurethane foam in particular), nonwoven, super-absorbent polymer layer, or a combination of these materials.

The bandages made from the hydrocolloidal adhesive mass of the invention may be of any geometric shape, e.g. square, rectangular, circular or oval, and may be of any size and will be adapted to the surface of the part to be treated or protected. For example, a bandage for the treatment of the bulb will be of a rectangular shape about 7 cm long and 4 cm wide, while a bandage for the treatment of ulcers will be of a square shape about 10 cm sideways.

It is practical to cover the surface of the hydrocolloidal adhesive mass containing the agglomerates with a protective film or film to be removed, for example by peeling, before applying the dressing to the wound and/or skin.

The resulting assembly can itself be wrapped in a watertight protective package, for example, made of polyethylene-aluminium complexes or in blisters.

The invention will be illustrated by the following non-limiting examples.

EXAMPLE 1: Preparation of a standard hydrocolloid dressing

A hydrocolloidal adhesive mass was prepared consisting of the following compounds (quantity expressed in weight per 100 grams of mass).

N°	Composés	Quantité (en poids pour 100 grammes)
1		14,144
2		3,536
3		12,376
4		6,542
5		26,521
6		35,714
7		0,460
8		0,354
9		0,354

This hydrocolloidal adhesive mass was prepared by applying the following process:

In a Z-arm blender at a set temperature of 140°C, compounds 1, 2, 3, 8 and 9 were introduced.

In the 30th minute, we added compound 4.

In the 40th minute, we added the compound 7.

In the 45th minute, we added the compound 5.

In the 60th minute, we added compound 6.

The mixer was emptied in the 80th minute.

The adhesive hydrocolloid mass was heated to a temperature of 110 to 130°C and then coated on a support consisting of a polyurethane film 30 μm thick. The complex formed from the hydrocolloid mass and the support was then cut into individual dressings, covered at the free adhesive hydrocolloid surface with protective siliconated polyester fins.

EXAMPLE 2: Preparation of a pasturage according to the invention (a) Preparation of maltodextrin based agglomerates

Maltodextrin agglomerates were prepared by spraying an aqueous solution on a maltodextrin powder in a fluidised air bed granulator.

Err1:Expecting ',' delimiter: line 1 column 173 (char 172)

(b) Deposition of agglomerates on the surface of a hydrocolloidal adhesive mass

The hydrocolloidal adhesive mass prepared in example 1 was heated to a temperature of 110 to 130°C and then coated on a support consisting of a polyurethane film 30 μm thick. The complex formed by the hydrocolloidal adhesive mass and the polyurethane film was cut into individual dressings.

The hydrocolloidal adhesive mass of the maltodextrin agglomerates was then deposited on the free surface (not bound to the support).

These agglomerates were deposited in a quantity of between 100 and 150 g/m2.

These agglomerates were deposited in the centre of the dressing covering a substantial 15% of the free surface of the adhesive.

The surface of the adhesive hydrocolloidal mass containing the agglomerates was covered with protective silicone polyester fins.

EXAMPLE 3: Demonstration of the properties of the bandage according to the invention

The adhesion of the dressings as prepared in examples 1 and 2 was measured after contact with physiological serum to simulate wound exudation to assess the difference in withdrawal behaviour between a dressings comprising a traditional hydrocolloid adhesive (example 1) and a dressings according to the invention comprising a hydrocolloid adhesive (example 2) with a surface intended to come into contact with the skin containing clumps.

Err1:Expecting ',' delimiter: line 1 column 88 (char 87)

The equipment

Specifically, this method was implemented by means of the apparatus shown in Figure 1.

This apparatus consists essentially of: a cylindrical probe 1 with a finely polished end capable of moving longitudinally (from bottom to top in the example shown) through a probe 2 guide consisting of a cylinder with a free hole drilled in its centre allowing the probe to pass freely without friction; an electronic dynamometer comprising a movable jaw 4 which can be connected to probe 1 by a chain 5 and a base 6 on which a plate 7 can be mounted; the said dynamometer being furthermore connected to a system for the acquisition and recording of data such as in particular the pressure downward of the probe, the probe's docking speed on the adhesive, the time between contact and the adhesive and the speed of the probe upwards.

Samples Standard filling

Following the experimental protocol in example 1, a substantially square bandage with a side of 20 cm was prepared.

This bandage was covered with double-sided adhesive tape on the side forming the support.

Circular samples of the same surface as the probe were cut into the whole of the above-mentioned bandage and tape using a circular 30 mm diameter strip.

The invention of the gasket

A second set of samples of the same nature and size was prepared.

Maltodextrin agglomerates such as those prepared in example 2 were deposited on the surface of these samples (excess agglomerates having been removed to cover the sample surface evenly).

Method of operation:

The 7th tray was mounted on the dynamometer's 6th stand.The 5th probe chain was fixed in the dynamometer's 4th movable jaw.The 1st probe was cleaned with a solvent (this operation being repeated before each measurement).A sample (double side) was applied as previously prepared to the probe.50 μl of physiological serum was deposited on the 7th tray in the middle of the area bounded by the probe guide.The parameters of the dynamometer (descent speed, pressure to touch, contact time and climb speed) were programmed.The following measurement was carried out: where F = Force expressed in N and S = Area expressed in m2.

The test parameters:

Application force: 1.7 kPa (aluminium probe of 121 g and diameter of 30 mm) Test speed: 300 mm/minRoll pressing: 4 kgContact time: 1 s

Measurements were made on 3 samples of each of the standard dressings and according to the invention and repeated 6 times.

Results:

The results of the measurements thus made, expressed in kPa, are given in Table I.

Essai N°	Exemple 1	Exemple 2
1	138,8	30,1
2	182,8	25,8
3	171,2	27,7
4	160,7	34,5
5	134,4	21,7
6	194	27,7

Observations of the behaviour of dressings in examples 1 and 2 in the presence of physiological serum.

Conditions	Observations après contact avec sérum physiologique
Exemple 1 + 50µl sérum physiologique	Gélification totale après 15 minutes
Exemple 2 +50µl sérum physiologique	Solubilisation en une seconde

The Commission's conclusions

The almost total solubilization of the agglomerates is very rapid (1s).

Err1:Expecting ',' delimiter: line 1 column 54 (char 53)

When the hydrocolloidal adhesive mass of the dressing contains agglomerates, the adhesion to removal of the agglomerate becomes minimal when it comes into contact with physiological serum, even in very small quantities.

Thus, a dressing according to the invention, i.e. comprising a hydrocolloidal adhesive mass bearing water-soluble or gellifiable particle aggregates at its surface intended to come into contact with the wound, can be easily repositioned after a first application within seconds of that first application.

Claims (10)

1. A wound dressing comprising an adhesive mass comprising hydrocolloids, characterized in that the dressing comprises, on a portion at least of the surface of the adhesive mass intended to come into contact with the wound in the position of use, a plurality of agglomerates composed of particles bonded to one another, preferably according to a multilayer configuration, said particles being composed, for 90% at least and preferably 95% at least of them, of one (or more) material(s);

   - chosen from

   - polysaccharides and in particular starch, modified starches, maltodextrin, gums, such as, in particular, gum arabic, xanthan gum or acacia gum, pullulan, dextrans, cellulose, cellulose derivatives, such as, in particular, methylcellulose, hydroxypropylmethylcellulose, hydroxypropylcellulose or hydroxyethylcellulose, sugars, pectin, alginates, carragheenans or agar;

   - proteins, in particular gelatin, albumin, collagen and casein;

   - superabsorbent synthetic polymers, in particular polyacrylates;

   - water-soluble synthetic polymers, in particular polyvinyl alcohol;

   and the mixtures of these compounds; and

   - capable of dissolving or gelling in less than 10 seconds and more preferably in less than 1 second on contact with the exudates from the wound.
2. The dressing as claimed in claim 1, characterized in that the abovementioned particles have a mean size of 500 nm to 1000 µm, preferably of 1 µm to 500 µm.
3. The dressing as claimed in either of the preceding claims, characterized in that the abovementioned agglomerates have a mean size of 5 to 2000 µm.
4. The dressing as claimed in one of the preceding claims, characterized in that the abovementioned agglomerates are present in an amount of 5 to 500 g per m² and preferably of 10 to 150 g per m² of dressing.
5. The dressing as claimed in one of the preceding claims, characterized in that the abovementioned agglomerates cover from 10 to 60% of the surface of the adhesive mass intended to come into contact with the wound in the position of use.
6. The dressing as claimed in one of the preceding claims, characterized in that the abovementioned material constituting the particles is maltodextrin.
7. The dressing as claimed in one of the preceding claims, characterized in that the agglomerates comprise one or more active substance(s) chosen from healing accelerators, antifungals, antimicrobials or antibacterials, moisturizing agents, local anesthetics, anti-inflammatories or a mixture of these compounds.
8. The dressing as claimed in claim 7, characterized in that the abovementioned active substance is hyaluronic acid.
9. The dressing as claimed in one of the preceding claims, characterized in that it comprises a backing.
10. The dressing as claimed in one of the preceding claims, characterized in that it comprises an absorbent layer situated between the backing and the hydrocolloid mass.