CN1787810B - Cladribine formulations for improved oral and transmucosal delivery - Google Patents

Abstract

The present invention provides a composition of cladribine and cyclodextrin which is particularly suitable for oral and buccal administration of cladribine.

Description

Cladribine formulations for improved oral and transmucosal delivery

technical field

The present invention relates to compositions comprising cladribine-cyclodextrin complexes formulated into solid oral dosage forms or transmucosal dosage forms, and to methods of enhancing the oral and transmucosal bioavailability of cladribine.

Background technique

Cladribine is an acid-labile drug that has the chemical structure described below:

It is also known as 2-chloro-2'-deoxyadenosine or 2-CdA.

Cladribine is an antimetabolite used in the treatment of lymphoproliferative disorders. It has been used in the treatment of experimental leukemias such as L1210, clinically in hairy cell leukemia and chronic lymphocytic leukemia, and in Waldenstrom's macroglobulinemia. It has also been used as an immunosuppressant and as a drug to treat a variety of autoimmune diseases, including rheumatoid arthritis, inflammatory bowel disease (e.g., Crohn's disease, ulcerative colitis) and multiple Sexual sclerosis (see eg, J. Liliemark, Clin. Pharmacokinet, 32(2):120-131, 1997). It has also been studied experimentally or clinically, for example in lymphoma, Langerhans cell histiocytosis, lupus erythematosus, chronic plaque psoriasis, Sezary syndrome, Bing-Neel syndrome, recurrent glia tumors and solid tumors.

Oral delivery of drugs is often preferred over parenteral delivery for a number of reasons, starting with patient compliance, or because of cost or therapeutic considerations. Oral dosage forms can reduce repeated visits to healthcare personnel, or the discomfort of injections or the number of prolonged infusions associated with some active drugs, thereby enhancing patient compliance. In an era of increasing healthcare costs, the cost reductions associated with oral or transmucosal administration relative to the cost of parenteral administration become even more important. The cost of parenteral administration is much higher because of the need for a health care professional to administer cladribine at the health care provider's site, including all additional costs associated with this administration. Moreover, in some cases, therapeutic considerations, such as the need for sustained release of cladribine over an extended period of time, can only practically be met by oral or transmucosal delivery.

However, to date, oral and transmucosal delivery of cladribine has the following disadvantages: low bioavailability (see, for example, J. Liliemark et al., J. Clin. Oncol., 10 (10): 1514-1518, 1992 ), and suboptimal interpatient variability (see, eg, J. Liliemark, Clin. Pharmacokinet, 32(2):120-131, 1997). See also, Poor absorption and pH-dependent instability reported by A. Tarasuik et al. (Arch. Immunol. et Therapie Expert., 42:13-15, 1994).

Cyclodextrins are cyclic oligosaccharides composed of cyclic α-(1→4) linked D-glucopyranose units. Cyclodextrins with 6-8 units have been named α-, β- and γ-cyclodextrins, respectively. The number of units determines the size of the conical cavity, which characterizes the cyclodextrin and entraps the drug, forming a stable complex. A number of α-, β- and γ-cyclodextrin derivatives are known in which one or more of the hydroxyl groups has been replaced by ether or other groups. Thus, these compounds are known as complexing agents and have previously been used in the pharmaceutical field to form inclusion complexes with water-insoluble drugs, thereby rendering them soluble in aqueous media.

More recently, Schultz et al. have described complexation and solubilization of cladribine with cyclodextrins in US Patent No. 6,194,395B1. The Schultz et al. patent primarily addresses the previously described problems inherent in aqueous formulations of cladribine, particularly for subcutaneous and intramuscular injections. Schultz et al. have found that cladribine is not only significantly more soluble in aqueous media when formulated with cyclodextrins, but also more stable to acid-catalyzed hydrolysis when combined with cyclodextrins. The latter finding is particularly useful for formulating solid oral dosage forms, where compounds would normally undergo hydrolysis in the acidic pH of gastric contents. Schultz et al. do not appear to describe any actual work with solid oral dosage forms. In fact, they describe only one method of making a solid dosage form, a melt extrusion method in which cladribine and cyclodextrin are mixed together with other optional additives and then heated until melted. Also, the broad dosage ranges listed in this patent of 1 mg to 15 mg cladribine and 100 mg to 500 mg cyclodextrin indicate the specific amount of cyclodextrin that should be present relative to a given amount of cladribine in a solid oral dosage form Not critical. Indeed, these dosage ranges include many combinations which may be suitable as mixtures but not for complex formation. For example, the ratio of 1 mg cladribine to 500 mg cyclodextrin contains too much cyclodextrin so that the drug cannot easily leave the complex and fulfill its therapeutic function. On the other hand, 15 mg of cladribine and only 100 mg of cyclodextrin is insufficient to complex this amount of cladribine.

Although the patent of Schultz et al. proposes to improve the stability of cladribine in the oral dosage form by combining/complexing with cyclodextrin, it does not propose to improve the oral bioavailability of the drug in this way; in fact, the patent does not describe Or propose a method of enhancing or maximizing the bioavailability of cladribine from a solid oral dosage form of cladribine and cyclodextrins or a composition specially designed for this purpose. Furthermore, Schultz et al. do not propose a cladribine/cyclodextrin combination for transmucosal administration, that is, in a form intended for administration through the mucosa lining the nasal, oral, vaginal, or rectal cavities rather than the orogastric route. , not to mention enhanced bioavailability of the drug when administered in this dosage form.

Many people have studied the solubility of specific drugs in water containing different concentrations of selected cyclodextrins to demonstrate that increasing the concentration of cyclodextrins can increase the solubility of the drug at selected temperature and pH levels, as for example in the patent of Schultz et al. reported in. Phase solubility studies have also been performed by various persons to elucidate the nature of complex formation, e.g., whether cyclodextrin and drug form a 1:1 complex or a 1:2 complex; see, e.g., U.S. Patent No. 4,497,803, which relates to inclusion complexes of lankacidin antibiotics with cyclodextrins, and U.S. Patent No. 4,478,995 to Shinoda et al., which relates to (2′-benzyloxycarbonyl)phenyltrans-4-guanidinomethyl A complex of acid addition salt of cyclohexanecarboxylate and cyclodextrin.

In the pharmaceutical field, it has become routine technique to use excess cyclodextrin in solid dosage forms where cyclodextrins are used to enhance drug dissolution, unless the solubility would make the excess cyclodextrin result in a dosage form that is too large. Common sense suggests that for solid oral dosage forms, especially acid labile drugs such as cladribine, an excess of cyclodextrin is expected to protect the drug in the acidic environment of the stomach and ideally transport it across the intestinal wall/gastric mucosa, still Protected as a complex with cyclodextrin. In the bloodstream, away from the deleterious effects of gastric acid, the drug is expected to dissociate from the complex and perform its therapeutic function.

Although Schultz et al. teach that a cladribine-cyclodextrin complex increases the aqueous solubility and acid stability of cladribine, the prior art does not suggest that the complex should be administered in a solid oral or transmucosal dosage form. , how to maximize or enhance the benefit of the compound in terms of bioavailability and interpatient variability.

Summary of the invention

It has now been found that an excess of cyclodextrin inhibits the absorption of cladribine in solid oral or transmucosal dosage forms containing cladribine-cyclodextrin complex, solid Oral or transmucosal dosage forms can improve oral and/or transmucosal bioavailability and/or achieve lower inter- and/or intra-patient variability of the drug.

The present invention provides a pharmaceutical composition comprising a saturated cladribine-cyclodextrin complex formulated into a solid oral dosage form or a transmucosal dosage form substantially free of cladribine exceeding the maximum amount of cladribine in the complex. The minimum amount of cyclodextrin required for oxidization. In a particular aspect of the invention, the pharmaceutical composition comprises a saturated cladribine-cyclodextrin complex formulated into a solid oral dosage form or a transmucosal dosage form substantially free of more than substantially all of the cladribine maintained in the complexed form. The minimum amount of cyclodextrin required in the product. This composition provides cladribine in its highest thermodynamically active state when in contact with the gastric mucosa (in the case of oral dosage forms) or the rectal, vaginal, oral or nasal mucosa (in the case of transmucosal dosage forms).

The present invention also provides a method of increasing the oral or transmucosal bioavailability of cladribine comprising administering to a subject in need thereof a pharmaceutical composition comprising saturated cladribine-cyclodextrose prepared in a solid oral dosage form or a transmucosal dosage form The refined complex substantially does not contain more than the minimum amount of cyclodextrin required to maximize the amount of cladribine in the complex. In a specific aspect of the invention, the composition administered comprises a saturated cladribine-cyclodextrin complex formulated into a solid oral or transmucosal dosage form substantially free of more than maintaining substantially all of the cladribine at The minimum amount of cyclodextrin required in the complex.

The present invention also provides a method of increasing the bioavailability of cladribine from a solid oral dosage form or a transmucosal dosage form in a mammal in need of treatment with cladribine, the method comprising: (a) determining and selecting an amount of cladribine the minimum amount of cyclodextrin required to complex and maintain said selected amount of cladribine in the complex; (b) combine more than said selected amount of cladribine with said minimum amount of cyclodextrin combined in an aqueous medium; (c) removal of uncomplexed cladribine from the complexed medium; (d) removal of water from the resulting solution to obtain a dry saturated cladribine-cyclodextrin complex; (e) The dry saturated cladribine-cyclodextrin complex is formulated into a solid oral or transmucosal dosage form substantially free of more than the minimum amount required to maximize the amount of cladribine in the complex and (f) administering the dosage form orally or transmucosally to a mammal. In a specific aspect of the method, step (e) comprises preparing said dried saturated cladribine-cyclodextrin complex into a solid oral or transmucosal dosage form substantially free of more than substantially all of the Cladribine maintains the minimum amount of cyclodextrin required in the complex.

The invention also provides a method of treating a condition in a mammal responsive to administration of cladribine by administering a composition of the invention. Also provided is the use of cladribine in the manufacture of a pharmaceutical composition of the invention for administration to treat the symptoms of a cladribine responsive disorder and to enhance the oral or transmucosal bioavailability of cladribine.

In a specific embodiment, the present invention provides a new and particularly advantageous 1:2 complex of cladribine:γ-cyclodextrin. In a related embodiment, there is provided a mixture of a 1:1 cladribine:γ-cyclodextrin complex and a 1:2 cladribine:γ-cyclodextrin complex, wherein the 1:2 complex is dominant.

Description of drawings

A more complete appreciation of the present invention, and its many additional advantages, can be more readily understood by reference to the following detailed description and accompanying drawings, in which:

Figure 1 is a graphical representation of the results of a phase solubility study in which different cyclodextrin (CD) molar concentrations are plotted against different cladribine molar concentrations, with (♦) representing hydroxypropyl-β-cyclodextrin, (■) represents hydroxypropyl-β-cyclodextrin with added hydroxypropylmethylcellulose, and (▲) represents γ-cyclodextrin.

Figure 2 shows the plasma profile of cladribine following administration of a single 5 mg dose of cladribine to dogs, the data show the mean concentration of cladribine in plasma (pg/ml) ± standard deviation of 5-6 animals/group , plotted against time (hours), administering the following cladribine formulations: (◇) intravenous (i.v.) bolus injection; (*) saturated buccal cladribine γ-cyclodextrin complex; ( ×) saturated oral cladribine-hydroxypropyl-β-cyclodextrin complex; (●) saturated oral cladribine-γ-cyclodextrin complex; (○) cladribine with 10 Oral capsules of physical mixture of 1-fold excess of γ-cyclodextrin; (□) oral capsules of cladribine complex with 10-fold excess of γ-cyclodextrin; (▲) saturated oral cladribine-hydroxypropyl and (Δ) oral capsules of a physical mixture of cladribine and a 10-fold excess of hydroxypropyl-β-cyclodextrin.

Figure 3 compares the plasma profiles of cladribine after administration of a single dose of 5 mg to dogs, and the data show the mean concentration (pg/ml) ± 5-6 standard deviation of animals/group, versus time (hours) Graphing, administration of the following cladribine formulations: (◆) intravenous (i.v.) bolus injection, (●) saturated oral cladribine-γ-cyclodextrin complex, and (▲) saturated oral Cladribine-hydroxypropyl-β-cyclodextrin complex.

Figure 4 compares the plasma profile of cladribine after oral administration of a single dose of 5 mg cladribine to dogs, the data shows the standard deviation of the mean concentration (pg/ml) ± 5-6 animals/group, versus time ( hours) plotting, administering the following cladribine formulations: (●) saturated oral cladribine-γ-cyclodextrin complex; (○) cladribine with a 10-fold excess of γ-cyclodextrin Oral capsules of physical mixture; and (□) Oral capsules of cladribine complex with 10-fold excess of γ-cyclodextrin.

Figure 5 compares the plasma profile of cladribine after oral administration of a single dose of 5 mg to dogs, and the data show the standard deviation of the mean concentration (pg/ml) ± 5-6 animals/group, versus time ( hours) plotted with the following cladribine formulations administered: (▲) saturated oral cladribine-hydroxypropyl-β-cyclodextrin complex; and (△) cladribine with a 10-fold excess of hydroxy Oral capsule of a physical mixture of propyl-beta-cyclodextrin.

Figure 6 illustrates the mean cumulative area under the curve (AUC) (pg x h/ mL), where each logo is shown in Figure 2.

Detailed description of the invention

In the specification and claims, the following definitions and general descriptions apply.

Patents, published applications, and scientific literature cited herein build upon the knowledge of those skilled in the art and are hereby incorporated by reference in their entirety to the same extent as if each had been specifically and individually indicated to be incorporated by reference. In the event of any conflict between any document cited herein and the specific teachings of this specification, the latter shall prevail. Similarly, if there is any conflict between an art-understood definition of a word or phrase and a specifically taught definition of a word or phrase in this specification, the latter shall prevail.

The term "complex" as used herein refers to an inclusion complex in which the hydrophobic portion (nitrogen-containing ring system) of the cladribine molecule is inserted into the hydrophobic cavity of the cyclodextrin molecule.

As used herein, the terms "comprises" and "comprising," whether in transitional phrases or within the body of a claim, are to be read in an open sense. That is, the term should be understood as being synonymous with the phrases "having at least" or "comprising at least". When used in the context of a method, the term "comprising" means that the method includes at least the recited steps, but may also include other steps. When used in the context of a composition, the term "comprising" means that the composition includes at least the recited features or components, but may also include other features or components.

The terms "consisting essentially of" have a semi-closed meaning, that is, they do not allow the inclusion of steps or features or components that would materially alter the essential characteristics of the method or composition; for example, would significantly A step or feature or component that interferes with the intended properties of the compositions described herein, ie, that the method or composition is limited to the specified steps or materials and that does not materially affect the essential novel characteristics of the invention. The essential novel feature here is that a saturated cladribine-cyclodextrin complex in a solid oral or transmucosal dosage form is provided substantially free of more than the amount of cladribine in the complex is maximized The minimal amount of cyclodextrin required to provide improved bioavailability and/or lower inter-patient variability after administration. In a particular embodiment of the invention, the essential novel feature herein is that there is provided a saturated cladribine-cyclodextrin complex in a solid oral or transmucosal dosage form substantially free of more than substantially The minimum amount of cyclodextrin required to maintain all cladribine in the complex provides particularly enhanced bioavailability and/or low inter-patient and/or low intra-patient variability after administration.

The terms "consisting of" and "consisting of" are closed terms allowing only the stated steps or features or components to be included.

As used herein, the singular forms "a", "an" and "the" specifically include plural forms of the terms to which they refer, unless the context clearly dictates otherwise.

The term "about" is used herein to mean approximately, around, roughly or around. When the term "about" is used in conjunction with a numerical range, it modifies that range by extending the boundaries above and below the numerical values recited. Generally, the term "about" or "approximately" is used herein to modify a numerical value by a deviation of 20% above and below the stated value.

When used in conjunction with complexes of cladribine in cyclodextrins, the term "saturated" means that the complex is saturated with cladribine, that is, the complex contains Maximum amount of cladribine complexed with a given amount of cyclodextrin. Phase solubility studies can be used to provide this information, as described in more detail below (conditions for complexation are also described in more detail below). Alternatively, saturated complexes can be obtained empirically by simply adding cladribine to an aqueous solution of the cyclodextrin of choice until a precipitate (of uncomplexed cladribine) forms; finally, the precipitate is removed and frozen The solution is dried to obtain a dry saturated complex.

The expression "substantially", as in "substantially free" or "substantially all", means within 20% of the exact calculated amount. In the case of the expression "substantially free of more than the minimum amount of cyclodextrin required to maintain substantially all of the cladribine in the complex", from phase solubility studies as explained in more detail below, it follows that The minimum amount of cyclodextrin required to maintain cladribine in the complex. The actual amount of cyclodextrin should be within ±20% of this minimum value, preferably within ±10% of this minimum value, even more preferably within ±5% of this minimum value, and should be at least 90% or more, preferably at least 95% or more of the drug is maintained in the complex. On the other hand, when using the expression "substantially free of cyclodextrin in excess of the minimum amount required to maximize the amount of cladribine in the complex", a lower amount of cyclodextrin may be used, resulting in Greater amounts of uncomplexed cladribine may be present in the dosage form. This phenomenon occurs by using lower concentrations of cyclodextrin solutions for the complexation reaction and/or by performing complexation at the upper end of the temperature range described below. However, it is believed to be particularly beneficial to use sufficient cyclodextrin to maintain substantially all of the cladribine in the complex, thereby minimizing the amount of uncomplexed cladribine in the dosage form.

The term "inter-patient variability" refers to variability among patients to which a drug is administered. The term "within-patient variability" refers to the variance experienced by the same patient when the drug is administered at different times.

As used herein, recitation of numerical ranges for variables is intended to indicate that the invention can be practiced with the variable equivalent to any value within the range. Thus, for a variable that is discrete in nature, the variable can be equal to any integer value within the range, including the end values of the range. Similarly, for a variable that is essentially continuous, the variable can be equal to any real value within the numerical range, including the end values of the range. As an example, a variable described as having a value between 0-2 may be 0, 1, or 2 for an essentially discrete variable, or 0.0, 0.1, 0.01, 0.001 for an essentially continuous variable or any other real value.

In the specification and claims, singular forms include plural forms unless the context clearly dictates otherwise. As used herein, unless specifically stated otherwise, the word "or" is used in the "inclusive" sense of "and/or" rather than the "exclusive" meaning of "is/is".

Unless otherwise defined, technical and scientific terms used herein have the meanings commonly understood by those skilled in the art to which this invention belongs. Reference is made herein to various methodologies and materials known to those of skill in the art. Standard texts describing the fundamentals of pharmacology include Goodman and Gilman, The Pharmacological Basis of Therapeutics, 10th Edition, McGraw Hill Companies Inc., New York (2001).

Reference is made in greater detail below to specific embodiments of the invention. While the invention will be described in conjunction with these specific embodiments, it will be understood that it is not intended to limit the invention to these specific embodiments. On the contrary, it is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. The present invention may be practiced without some or all of these specific details. In other instances, well known process operations have not been described in detail in order not to unnecessarily obscure the present invention.

The present invention provides compositions and methods of making and using pharmaceutical compositions for achieving desirable pharmacokinetic properties. Such a composition arises from the discovery that cladribine is in its highest thermodynamic state when presented to the mucosa (gastric, nasal, rectal, buccal, sublingual or vaginal) through which it is to be absorbed A solution of cyclodextrin and cladribine was associated with improved cladribine absorption, as reflected by higher bioavailability and/or lower interpatient variability.

Without wishing to so limit the invention, it is assumed that upon dissolution (e.g., by contact with fluids such as body fluids), a dry composition of saturated cladribine-cyclodextrin complex without excess cyclodextrin will form partially saturated cladribine Cladribine solution, in which cladribine is in the highest thermodynamically active (HTA) state, thereby facilitating absorption. Cladribine has a rather low (though not negligible) intrinsic water solubility. Free cladribine formed upon dissociation from the complex in saturated aqueous solution exhibits a more stable activity level, and if excess cyclodextrin is present, cladribine seeks greater stabilization by recomplexing with cyclodextrin sex. By controlling the amount of cyclodextrin so that the dosage form contains substantially no more cyclodextrin than is required to maintain cladribine in the complex, cladribine in a partially saturated solution cannot readily combine with cyclodextrin recombine. Therefore, the cladribine will seek lower thermodynamic activity through absorption through the gastric mucosa (in the case of solid oral dosage forms) or through the nasal, buccal, vaginal or rectal mucosa (in the case of transmucosal dosage forms) / Greater stability state. Among other things, it is demonstrated below that this regimen improves bioavailability, possibly by avoiding or minimizing inhibition of cladribine absorption due to the presence of excess cyclodextrin. In the presence of a large excess of cyclodextrin, it is expected that cladribine in solution will recombine with the cyclodextrin. This would not achieve optimal bioavailability because if cladribine is to fulfill its therapeutic function, the drug must be removed from the complex that encapsulates it.

In view of the above, it is evident that optimal pharmaceutical compositions should be produced for solid oral or transmucosal dosage forms which are formulated to release a partially saturated solution of cladribine, wherein cladribine is in the form of its HTA status. In order to provide such a partially saturated solution in vivo, it is important to first identify the optimal ratio of cladribine to cyclodextrin, referred to herein as the HTA ratio, to be used in the solid dosage form. In the case of buccal dosage forms, by dissolving the saturated compound in a minimum amount of water, a highly concentrated solution is made which can be placed in the oral cavity to achieve the same effect.

The HTA ratio was determined empirically and identified as the ratio of cladribine to a particular cyclodextrin, which corresponds to the maximum amount of cladribine that can be complexed with a given amount of cyclodextrin. The HTA ratio can be determined using empirical methods such as phase solubility studies to examine the saturating concentration of cladribine that is soluble with different concentrations of cyclodextrin solutions. From this, the method can identify the concentration at which a saturated cladribine-cyclodextrin complex is formed. It should be noted that the molar ratios represented by the points on the phase solubility diagram indicate how many moles of cyclodextrin are the minimum required to maintain the drug in the complex under given conditions; this can then be converted to a weight ratio. For example, if the phase solubility diagram shows that 9 moles of a given cyclodextrin are required to maintain substantially all of cladribine in a saturated complex, then by multiplying moles of cladribine x its molecular weight and The proportion of moles x its molecular weight can be obtained as appropriate to optimize the weight ratio of the product. Phase solubility studies also provide information on the nature of the cladribine-cyclodextrin complex formed, e.g., whether the complex is a 1:1 complex (1 molecule of drug complexed with 1 molecule of cyclodextrin) or a 1:2 complex Complex (1 molecule of drug compounded with 2 molecules of cyclodextrin).

According to the invention, it is possible to start with either cyclodextrin or cladribine as a fixed variable, to which an excess of the other is added to identify different HTA data points (indicating a saturated cladribine-cyclodextrin complex), and Plot the resulting HTA line. Typically, cladribine is added to an aqueous solution containing a known concentration of cyclodextrin under conditions empirically found to promote complex formation. Concentrated solutions, eg, about 27% gamma-cyclodextrin and about 40% hydroxypropyl-beta-cyclodextrin, are particularly beneficial in one embodiment. Typically, compounding is performed at room temperature or with slight heating (up to about 50°C or even as high as 60°C). Excess cladribine that may be present is then removed and the concentration of cladribine in the complex is subsequently measured. The measured concentrations represent the saturation concentration of cladribine for a given cyclodextrin concentration. This method was repeated for different known concentrations of cyclodextrin until several data points were obtained. Each data point represents the saturation concentration of cladribine dissolved in a known concentration of cyclodextrin. The data points are then plotted showing the saturation concentration of cladribine for the different cyclodextrin concentrations used. This figure is a phase solubility diagram that can be used to determine the saturating amount of cladribine under given complexing conditions for any specific concentration of cyclodextrin used to form a saturated cladribine-cyclodextrin complex .

Those skilled in the art will appreciate that the concentration (and thus the HTA ratio) that saturates the cladribine-cyclodextrin complex formation can be identified by a number of alternative methods. Accordingly, any method known in the art suitable for identifying these concentrations is within the scope of the present invention.

It has been found that desirable pharmacological properties (improved bioavailability and/or lower inter- and/or intra-patient variability) are associated with the inclusion complexes of the invention.

Cyclodextrins within the scope of the present invention include the natural cyclodextrins α-, β- and γ-cyclodextrins and their derivatives, more particularly in derivatives in which one or more hydroxyl groups are substituted, for example by an alkane radical, hydroxyalkyl, carboxyalkyl, alkylcarbonyl, carboxyalkoxyalkyl, alkylcarbonyloxyalkyl, alkoxycarbonylalkyl or hydroxy-(mono- or polyalkoxy)alkyl; and Wherein each alkyl or alkylene group preferably contains up to 6 carbons. Substituted cyclodextrins are generally available in different degrees of substitution, for example, from 1 to 14, preferably from 4 to 7; the degree of substitution is the approximate average number of substituents on the cyclodextrin molecule, for example, in the hydroxypropyl - in the case of a β-cyclodextrin molecule, the approximate number of hydroxypropyl groups, all such variations are within the scope of the invention. Substituted cyclodextrins that may be used in the present invention include polyethers, eg, as described in US Patent No. 3,459,731. Other examples of substituted cyclodextrins include ethers wherein one or more hydrogens of the cyclodextrin hydroxyl groups are replaced by C _1-6 alkyl, hydroxy-C _1-6 alkyl, carboxy-C _1-6 alkyl Or C _1-6 alkoxycarbonyl-C _1-6 alkyl, or a mixed ether thereof. More specifically, such substituted cyclodextrins are ethers in which the hydrogens of one or more cyclodextrin hydroxyl groups are replaced by C _1-3 alkyl, hydroxy-C _2-4 alkyl or carboxy-C _{1- 2} alkyl, or more specifically replaced by methyl, ethyl, hydroxyethyl, hydroxypropyl, hydroxybutyl, carboxymethyl or carboxyethyl. The term "C _1-6 alkyl" is intended to include linear and branched saturated hydrocarbon groups having 1-6 carbon atoms, such as methyl, ethyl, 1-methylethyl, 1,1- Dimethylethyl, propyl, 2-methylpropyl, butyl, pentyl, hexyl, etc. Other cyclodextrins for use herein include glucosyl-β-cyclodextrin and maltosyl-β-cyclodextrin. Particularly useful in the present invention are beta-cyclodextrin ethers such as dimethyl-beta as described by M. Nogradi (1984) in Cyclodextrins of the Future, Vol.9, No.8, p. - Cyclodextrins, randomly methylated β-cyclodextrins, and polyethers such as hydroxypropyl-β-cyclodextrin, hydroxyethyl-β-cyclodextrin, hydroxypropyl-γ-cyclodextrin , and hydroxyethyl-γ-cyclodextrin, and thiobutyl ether, especially β-cyclodextrin thiobutyl ether. In addition to simple cyclodextrins, branched cyclodextrins and cyclodextrin polymers can also be used. Other cyclodextrins are described, for example, in Chemical and Pharmaceutical Bulletin 28: 1552-1558 (1980); Yakugyo Jiho No. 6452 (28 March 1983); Angew. Chem. Int. Ed. Engl. 19: 344-362 (1980) ; US Patent Nos. 3,459,731 and 4,535,152; European Patent Nos. EP 0 149 197A and EP 0197 571A; PCT International Patent Publication No. WO90/12035; and British Patent Publication GB2,189,245. Other documents that describe cyclodextrins for use in compositions according to the invention and provide guidance for the preparation, purification and analysis of cyclodextrins include the following: Jozsef Szejtli, Kluwer Academic Publishers (1988) in the chapter Cyclodextrin in Pharmaceuticals MLBender et al., Cyclodextrin Chemistry of Springer-Verlag, Berlin (1978); Advances in Carbohydrate Chemistry, Volume 12, edited by ML Wolffrom, Chapter "The Schardinger Dextrins" of Academic Press, New York, Dexter French, No. 189- 260 pages; J. Szejtli, Akademiai Kiado, Budapest, Hungary (1982) Cyclodextrin and their Inclusion complexes; I. Tabushi, Acc. Chem. Research, 1982, 15, pp. 66-72; W. Sanger, Angewandte Chemie, 92 , pp. 343-361 (1981); AP Croft et al., Tetrahedron, 39, pp. 1417-1474 (1983); Irie et al., Pharmaceutical Research, 5, pp. 713-716 (1988); Pitha et al., Iht.J. Pharm. 29, 73 (1986); US Patent Nos. 4,659,696 and 4,383,992; German Patent Nos. DE 3,118,218 and DE-3,317,064; and European Patent No. EP 0 094157A. Patents describing hydroxyalkylated derivatives of β- and γ-cyclodextrins include US Patent Nos. 4,596,795 and 4,727,064 to Pitha, US Patent Nos. 4,764,604, 4,870,060 to Müller, and US Patent No. 6,407,079 to Müller et al.

Cyclodextrins of particular interest for complexation with cladribine include: γ-cyclodextrin β- and hydroxyalkyl (e.g. hydroxyethyl or hydroxypropyl) derivatives of γ-cyclodextrin; - or carboxyalkyl (such as carboxymethyl or carboxyethyl) derivatives of γ-cyclodextrin; β-cyclodextrin thiobutyl ether; dimethyl-β-cyclodextrin; and randomly methylated beta-cyclodextrin. 2-Hydroxypropyl-β-cyclodextrin (HPβCD), 2-Hydroxypropyl-γ-cyclodextrin (HPγCD), randomly methylated β-cyclodextrin, dimethyl-β-cyclodextrin , β-cyclodextrin thiobutyl ether, carboxymethyl-β-cyclodextrin (CMβCD), carboxymethyl-γ-cyclodextrin (CMγCD) and γ-cyclodextrin (γCD) itself are particularly advantageous , especially gamma-cyclodextrin and hydroxypropyl-beta-cyclodextrin, most especially gamma-cyclodextrin.

As explained and exemplified herein, compositions of saturated cladribine-cyclodextrin complexes for use in the present invention can be prepared in a liquid environment under conditions that favor complex formation. The resulting liquid preparation can then be converted to a dry form suitable for administration as a solid oral or transmucosal dosage form.

A skilled artisan will appreciate that a variety of methods are available in the art for preparing the compositions described herein. One available method exemplified herein comprises the steps of mixing cladribine into an aqueous cyclodextrin solution, maintaining the complex medium at room temperature, and stirring for about 6 to about 24 hours, a time sufficient to achieve equilibrium, Uncomplexed cladribine that may be present is separated (eg, by filtration or centrifugation) and the saturated solution is lyophilized or lyophilized to form a solid saturated cladribine-cyclodextrin complex mixture.

Freeze-drying, also known as freeze-drying, consists of 3 basic stages: first the freezing stage, then the primary drying stage, and finally the secondary drying stage. Example 2 below provides details of performing the batch lyophilization as described. This can be further optimized by following the principles described in Xiaolin (Charlie) Tang and Michael J. Pikal in Pharmaceutical Research, Vol. 21, No. 2, Feb. 2004, 191-200, which are incorporated herein by reference and relied on in their entirety. method.

The pharmaceutical compositions according to the invention may optionally comprise one or more excipients or other pharmaceutically inert components. However, one of the advantages of the present invention is that the pharmaceutical form of cladribine as described herein can be prepared using the minimum amount of excipients necessary for shaping and producing a particular form (eg tablet or patch). One can choose from those excipients which do not interfere with cladribine, cyclodextrin or complex formation.

Optionally in a pharmaceutically acceptable medium and any of the well-known pharmaceutically acceptable carriers, diluents, binders, lubricants, disintegrating agents, purifying agents, flavoring agents, coloring agents and excipients Formulate dosage forms together (see Handbook of Pharmaceutical Excipients, Marcel Dekker Inc., New York and Basel (1998); Lachman et al., eds., The Theory and Practice of Industrial Pharmacy, 3rd Edition, (1986); Lieberman et al., Eds. Pharmaceutical Dosage Forms , Marcel Dekker Inc., New York and Basel (1989); and The Handbook of Pharmaceutical Excipients, 3rd ed., American Pharmaceutical Association and Pharmaceutical Press, 2000); see also Rermington's Pharmaceutical Sciences, 18th ed., Gennaro, Mack. Publishing , Easton, PA (1990) and Remington: The Science and Practice of Pharmacy, Lippincott, Williams & Wilkins, (1995)). A simple solid oral or transmucosal dosage form consists of a saturated cladribine-cyclodextrin complex compressed with a small amount (eg about 1% by weight) of a suitable binder or lubricant such as magnesium stearate.

In a specific embodiment, a saturated cladribine-cyclodextrin complex is used for transmucosal or oral administration of cladribine.

As used herein, "mucosal membrane" refers to the epithelial membrane lining the nasal, oral, vaginal, and rectal cavities, as well as the epithelial membrane lining the stomach (gastric mucosa). As used herein, mucosal and transmucosal are used interchangeably. Methods and forms of transmucosal delivery are well known in the art. They include buccal and sublingual tablets, lozenges, adhesive patches, gels, solutions or sprays (powder, liquid or aerosol) and suppositories or foams (for rectal or vaginal administration). Transmucosal delivery methods and forms exclude methods and forms for oral use, which are intended to be swallowed, referred to herein simply as oral dosage forms, although they ultimately deliver the drug through the gastric mucosa. When the transmucosal form is a liquid, it can be obtained by dissolving the saturated complex in a minimum amount of water, e.g. dissolving 500 mg of the saturated complex with HPβCD in 0.5 ml of water (50% w/w solution), or dissolving 500 mg of saturated γCD complex was dissolved in 1.0 ml of water. A few drops of such a solution may be placed in the oral cavity and left there for about 2 minutes to allow absorption through the oral mucosa. However, solid transmucosal dosage forms are generally preferred over liquid forms.

In some cases, by adding different excipients and additives to increase solubility or enhance penetration, for example by modifying the microenvironment, or by adding mucosal-adhesive excipients to improve the contact between the delivery system and the mucosal tissue, Oral or mucosal absorption can be further enhanced.

Oral drug delivery can be achieved by placing the buccal dosage unit between the lower gingiva and the opposing oral mucosa of the individual receiving the drug. Excipients or vehicles suitable for buccal administration of the drug can be used, including any such material known in the art, for example, any liquid, liquid, Gels, solvents, liquid diluents, solubilizers, etc. The solid dosage unit is formulated to gradually dissolve over a predetermined period of time to produce a substantially saturated solution of the drug in oral saliva, allowing transmucosal absorption of cladribine, wherein drug delivery is provided substantially throughout that time period. Buccal dosage units may also contain lubricating agents, for example, magnesium stearate, and the like, to facilitate production. Other components that may be included in the buccal dosage unit include, but are not limited to, flavorings, penetration enhancers, diluents, binders, and the like. The remainder of the buccal dosage unit may comprise a bioerodible polymeric carrier and any excipients that may be required, such as binders, disintegrants, lubricants, diluents, flavoring agents, coloring agents, etc., and/or other active drugs.

其它合适的聚合物包括但不限于水解的聚乙烯醇、聚氧化乙烯(例如，Sentry

聚丙烯酸酯(例如，

乙烯基聚合物和共聚物、聚乙烯吡咯烷酮、葡聚糖、瓜尔胶、果胶、淀粉和纤维素聚合物，例如羟丙基甲基纤维素(例如，羟丙基纤维素(例如，羟丙基纤维素醚、羟乙基纤维素、羧甲基纤维素钠、甲基纤维素、乙基纤维素、乙酸-邻苯二甲酸纤维素、乙酸-丁酸纤维素等。剂量单位仅仅需要含有饱和的克拉屈滨-环糊精复合物。但是，在有些情况下，它可理想地包含一种或多种前述的载体和/或一种或多种其它组分。例如，可以包含润滑剂来方便生产该剂量单位的工艺过程；润滑剂还可以优化蚀解速率和药物流出。如果存在润滑剂，其量级为剂量单位的0.01重量％至约2重量％、优选约0.01重量％至1.0重量％。合适的润滑剂包括但不限于硬脂酸镁、硬脂酸钙、硬脂酸、硬脂酰延胡索酸钠、滑石、氢化植物油和聚乙二醇。The buccal carrier may comprise a polymer of sufficient viscosity to ensure that the dosage unit adheres to the oral mucosa for the period of time necessary during which cladribine is delivered to the oral mucosa. In addition, the polymeric carrier is gradually "bioerodible", that is, the polymer hydrolyzes at a predetermined rate upon exposure to moisture. Any polymeric carrier that is pharmaceutically acceptable, provides a suitable degree of adhesion and the desired drug release profile and is compatible with the cladribine and any other ingredients that may be present in the buccal dosage unit to be administered can be used. Typically, polymeric carriers include hydrophilic (water-soluble and water-swellable) polymers that adhere to the wetted surfaces of the oral mucosa. Examples of polymeric carriers used herein include acrylic acid polymers and copolymers, for example, those known as "carbomers", for example,

Other suitable polymers include, but are not limited to, hydrolyzed polyvinyl alcohol, polyethylene oxide (e.g., Sentry

Polyacrylate (eg,

Vinyl polymers and copolymers, polyvinylpyrrolidone, dextran, guar gum, pectin, starch and cellulosic polymers such as hydroxypropylmethylcellulose (e.g., Hydroxypropyl cellulose (eg, Hydroxypropyl cellulose ether, hydroxyethyl cellulose, sodium carboxymethyl cellulose, methyl cellulose, ethyl cellulose, cellulose acetate-phthalate, cellulose acetate-butyrate, etc. Dosage units need only contain saturated cladribine-cyclodextrin complex. However, in some cases it may be desirable to comprise one or more of the aforementioned carriers and/or one or more of the other components. For example, a lubricant may be included to facilitate the process of manufacturing the dosage unit; the lubricant may also optimize the rate of erosion and drug efflux. Lubricants, if present, will be present in the order of 0.01% to about 2%, preferably about 0.01% to 1.0% by weight of the dosage unit. Suitable lubricants include, but are not limited to, magnesium stearate, calcium stearate, stearic acid, sodium stearyl fumarate, talc, hydrogenated vegetable oils and polyethylene glycols.

According to the invention, the saturated cladribine-cyclodextrin complex can also be administered in the form of suppositories or foams for vaginal or rectal administration. These compositions may be prepared by known methods, for example, in the case of suppositories, by mixing the saturated complex with suitable non-irritating excipients or binders, which are solid at ordinary temperatures, But it is a liquid at vaginal or rectal temperature, so it will melt in the vagina or rectum, releasing the medicine. Such materials include cocoa butter and polyethylene glycols. Traditional binders and carriers include, for example, polyalkylene glycols or triglycerides [eg PEG 1000 (96%) and PEG 4000 (4%)]. Such suppositories may be formed from mixtures containing the active ingredient in the range of about 0.5% to about 10%, preferably about 1% to about 2%, w/w.

For intranasal use, a saturated powder spray or ointment of the complex may be used, preferably in powder form.

Also, for human use, buccal dosage forms, particularly buccal tablets or wafers or discs, advantageously have a disintegration time of about 15-30 minutes, or buccal patches (in which the drug is only released from adhering to the oral cavity The side on the mucosa that releases, while the other side is impermeable), is of interest. Oral administration may utilize the invention of Nagai et al. described in US Pat. Nos. 4,226,848 and 4,250,163, incorporated herein by reference in their entirety and relied upon. Thus, for use herein, oral mucosa-adherent tablets can be prepared comprising: (a) a water-swellable and mucosa-adherent polymeric matrix comprising from about 50% to about 95% by weight of fibers plain ether and about 50% to about 95% by weight of an acrylic acid homopolymer or copolymer or a pharmaceutically acceptable salt thereof, and (b) a suitable amount of cladribine dispersed therein as a compound with 2-hydroxypropyl- Saturated complexes of β-cyclodextrin or γ-cyclodextrin. Ideally, for storage stability, the tablet is anhydrous.

The methods and pharmaceutical compositions described herein can provide new therapeutic modalities for the treatment of patients in need of treatment with cladribine. As demonstrated herein, the present invention addresses the problem of poor bioavailability traditionally associated with oral cladribine. Alternatively, the orogastric route can be avoided entirely by administering a transmucosal delivery form.

The compositions of the invention are particularly useful as a therapy for any cladribine-responsive disease. Several disease states that respond to cladribine are well documented in the literature (see below). For any disease state of interest, an effective amount of the optimized cladribine-cyclodextrin complex is used (eg, an amount effective for treating multiple sclerosis, rheumatoid arthritis, or leukemia).

The terms "therapeutically effective amount" or "effective amount" are used to denote treatment at a dose effective to achieve the therapeutic result sought. Therapeutically effective dosages described in the literature include therapeutically effective amounts for hairy cell leukemia (0.09 mg/kg/day for 7 days), multiple sclerosis (about 0.04 to about 1.0 mg/kg/day) 5,310,732 (inflammatory bowel disease); 5,401,724 (rheumatoid arthritis); 5,424,296 (malignant astrocytoma ); 5,510,336 (Histiocytosis); 5,401,724 (Chronic Myelogenous Leukemia); and 6,239,118 (Atherosclerosis).

Additionally, different dosages and administration regimens have been described in the literature for the treatment of multiple sclerosis; see, eg, Romine et al., Proceedings of the Association of American Physicians, Vol. 111, No. 1, 35-44 (1999) ; Selby et al., The Canadian Journal of Neurological Sciences, 25, 295-299 (1998); Tortorella et al., Current Opinion in Investigational Drugs, 2(12), 1751-1756 (2001); Rice et al., Neurology, 54, 1145-1155 (2000); and Karlsson et al., British Journal of Haematology, 116, 538-548 (2002); all of which are hereby incorporated by reference and relied upon in their entirety.

Furthermore, the route of administration of the therapeutically effective dose as taught in the literature should be taken into account. Although the compositions of the present invention optimize the bioavailability of cladribine following oral or transmucosal administration, it should be understood that even optimal bioavailability from oral or transmucosal dosage forms cannot be expected to approach that obtained in intravenous Bioavailability obtained after administration, especially at earlier time points; see, eg, Figure 3, infra. Thus, it is often necessary to increase the doses recommended for intravenous administration in order to achieve suitable doses for incorporation into solid oral or transmucosal dosage forms. It is currently considered that for the treatment of multiple sclerosis, 10 mg of cladribine in this solid dosage form as a saturated cladribine-cyclodextrin complex is administered once daily for 5-7 days in the first month, Repeat for another 5-7 days for two months, then 10 months without treatment. Alternatively, patients are administered a dose of 10 mg once daily, 5-7 days per month, for 6 months, followed by 18 months of no treatment. For additional dosing information, see also U.S. Provisional Patent Application No. [IVAX0021-P-USA/Attorney's Docket No. 033935-011], and U.S. Provisional Patent Application No. [IVAX0022-P-USA/Attorney's Docket No. 033935-012 ], both titled "Cladribine Regimen for Treating Multiple Sclerosis", filed March 25, 2004, which are hereby incorporated by reference in their entirety.

Furthermore, the skilled person will appreciate that the therapeutically effective amount of cladribine administered herein can be lowered or increased by fine-tuning and/or by administering cladribine according to the invention together with other active ingredients. Thus, the present invention provides methods of tailoring administration/treatment to the particular circumstances of a given mammal. A therapeutically effective amount can be readily determined, for example, empirically starting with relatively small amounts and increasing them while evaluating beneficial effects.

即一种单克隆抗体；阿仑单抗人源化的抗-CD52单克隆抗体；4-氨基吡啶(也称作4-AP和氨吡啶)，即一种能阻断神经元中的钾通道的药物；和金刚烷胺，即一种可以改善肌肉控制和减少肌肉僵硬且用于减轻多发性硬化中的疲劳症状的抗病毒药物，为此目的，还可以使用匹莫林和L-肉毒碱(一种草药制品)。在毛细胞白血病的治疗中，其它的活性成分可包括干扰素α，喷司他丁，氟达拉滨，美罗华(一种抗-CD 20单克隆抗体)和抗-CD22重组免疫毒素BL 22；其它附加的活性成分在其它类型的白血病中可能是适当的。在类风湿性关节炎的治疗中，可以选择许多其它的活性成分。它们包括NSAIDS(非甾体抗炎药)，其有3种类型：水杨酸盐例如阿司匹林，传统的NSAIDS例如布洛芬和吲哚美辛，和COX-2抑制剂例如塞来昔布罗非考昔美洛昔康

伐地考昔

lumiracoxib

和艾托考昔

可以与本发明联合使用的用于治疗类风湿性关节炎的其它药物包括DMARDS，糖皮质激素，生物反应调节剂和非-NSAID的止痛剂。DMARDS是疾病调节性抗风湿药，其包括氨甲蝶呤，氯喹，来氟米特柳氮磺吡啶，金，青霉胺，环孢霉素，甲基环磷酰胺和硫唑嘌呤。糖皮质激素包括地塞米松，泼尼松龙，曲安西龙和许多其它药物。生物反应调节剂(其能恢复免疫系统的与疾病斗争的能力)包括依那西普一种肿瘤坏死因子抑制剂，英夫利昔单抗其也是一种抗-TNF药，阿那白滞素

即一种选择性的IL-1阻断剂，和

即一种人单克隆抗体，其是另一种抗-TNF药。非-NSAID的止痛剂包括对乙酰氨基酚以及麻醉性的止痛剂例如氢可酮，羟考酮和右丙氧芬。一般而言，其作用机理与克拉屈滨不同的那些药物对于和本文所述的克拉屈滨组合物一起治疗是特别有益的。可以将单一剂型的经口或透粘膜施用途径有效的、且与本发明克拉屈滨复合物相容的那些药物整合进本剂型中；另外，它们当然可以以适合它们的量、频率和施用途径分开地施用。As mentioned in the preceding paragraphs, the administration of cladribine according to the invention may be accompanied by the administration of one or more other active ingredients for the treatment of cladribine-responsive conditions. The other active ingredients are administered in a route of administration, dosage and frequency appropriate for each other active ingredient and the condition being treated. For example, in the treatment of multiple sclerosis, other useful drugs include interferon beta Identical to the naturally occurring protein found in the human body; glatiramer acetate That is, random chains (polymers) of the amino acids glutamic acid, lysine, alanine, and tyrosine; natalizumab

a monoclonal antibody; alemtuzumab A humanized anti-CD52 monoclonal antibody; 4-aminopyridine (also known as 4-AP and fampridine), a drug that blocks potassium channels in neurons; and amantadine, a Antiviral drugs that improve muscle control and reduce muscle stiffness and are used to reduce symptoms of fatigue in multiple sclerosis, also pemoline for this purpose and L-carnitine (an herbal preparation). In the treatment of hairy cell leukemia, other active ingredients may include interferon α, pentostatin, fludarabine, rituximab (an anti-CD 20 monoclonal antibody) and anti-CD22 recombinant immunotoxin BL 22; Other additional active ingredients may be appropriate in other types of leukemia. In the treatment of rheumatoid arthritis, many other active ingredients can be selected. They include NSAIDS (non-steroidal anti-inflammatory drugs), which come in 3 types: salicylates such as aspirin, traditional NSAIDS such as ibuprofen and indomethacin, and COX-2 inhibitors such as celecoxib Rofecoxib Meloxicam

Valdecoxib

lumiracoxib

and etoricoxib

Other drugs for the treatment of rheumatoid arthritis that may be used in conjunction with the present invention include DMARDS, glucocorticoids, biologic response modifiers and non-NSAID analgesics. DMARDS are disease-modifying antirheumatic drugs, which include methotrexate, chloroquine, leflunomide Sulfasalazine, gold, penicillamine, cyclosporine, methylcyclophosphamide, and azathioprine. Corticosteroids include dexamethasone, prednisolone, triamcinolone, and many others. Biological response modifiers (which restore the immune system's ability to fight disease) including etanercept A tumor necrosis factor inhibitor, infliximab It is also an anti-TNF drug, anakinra

i.e. a selective IL-1 blocking agent, and

That is, a human monoclonal antibody that is another anti-TNF drug. Non-NSAID analgesics include acetaminophen and narcotic analgesics such as hydrocodone, oxycodone, and dextropropoxyphene. In general, those drugs whose mechanism of action differs from that of cladribine are particularly beneficial for treatment with the cladribine compositions described herein. Those drugs which are effective for the oral or transmucosal route of administration of a single dosage form and which are compatible with the cladribine complexes of the invention can be incorporated into the present dosage form; in addition, they can of course be formulated in amounts, frequencies and routes of administration suitable for them. Administered separately.

As used herein, "treating" refers to alleviating, preventing, arresting the development of, controlling, alleviating, and/or treating symptoms in an individual to whom a compound of the invention has been administered, as compared to symptoms in an individual not treated according to the invention or reverse its symptoms. Practitioners will appreciate that subsequent treatment, using the compounds, compositions, dosage forms and methods described herein, will be determined based on sequential clinical evaluation by the skilled operator (physician or veterinarian). Such an evaluation would assist and inform the justification of whether to increase, decrease or continue a particular therapeutic dose and/or alter the administration regime.

The methods of the invention are intended for any subject/patient who may benefit from the methods of the invention. Thus, according to the present invention, the terms "subject" and "patient" include human and non-human subjects, especially domestic animals.

Any suitable materials and/or methods known to those of skill can be used in the practice of the present invention. However, preferred materials and methods are described. Materials and reagents, etc., mentioned in the following description and examples can be obtained from commercial sources unless otherwise stated.

The following examples are intended to further illustrate certain preferred embodiments of the invention and are not intended to be limiting. Those skilled in the art will recognize, or be able to ascertain, using no more than routine experimentation, many equivalents to the specific materials and methods described herein.

Example

Embodiment 1 phase solubility research

Phase solubility studies were performed as follows. Excess cladribine was added to cyclodextrin solutions of various concentrations of γ-cyclodextrin (γCD) or hydroxypropyl-β-cyclodextrin (HPβCD) and complexed as described in Example 2 below. Additionally, in one set of experiments, the effect of hydroxypropylmethylcellulose (HPMC) on compounding was investigated. Remove excess undissolved cladribine by filtration. Data points were obtained by detecting the amount of cladribine in the complex solution. The method was repeated using different known concentrations of cyclodextrin until several data points were obtained. These data points are then plotted, each data point representing the maximum amount of cladribine that can be complexed with a particular concentration of cyclodextrin, ie each point represents a saturated cladribine-cyclodextrin complex. Points on the line generated from the data points represent HTA ratios. Any point on this line represents a specific, unique saturated cladribine-cyclodextrin complex. Those skilled in the art will recognize that the same result can be obtained if an excess of cyclodextrin is added to a known concentration of cladribine solution.

As an example, cyclodextrin solutions at different concentrations were prepared and saturated with cladribine by providing an excess of cladribine. Table I below lists saturated cyclodextrin solutions of a given cyclodextrin for a given cyclodextrin concentration.

Table I

The molar concentration of cladribine to cyclodextrin in Table I is plotted and represented as Fig. 1 . The lines drawn for cladribine-HPβCD, cladribine-HPβCD and 0.1% HPMC and cladribine-γCD represent the maximum cladribine dissolution under the experimental conditions, i.e. the HTA ratio of cladribine concentration to cyclodextrin concentration . The area above each graph line represents the presence of excess insoluble cladribine. The area under each graph line represents the amount of cyclodextrin in excess of that required to maintain the complex in solution. Clearly, the data in Table I and Figure 1 show that HPMC, a known complex accelerator, has no effect at lower concentrations and has a negative effect at higher concentrations.

The HTA plot of cladribine-HP[beta]CD shown in Figure 1 is approximately linear; this is indicative of a 1:1 complex where 1 molecule of drug is complexed with 1 molecule of cyclodextrin. Figure 1 also shows that additional cyclodextrin is required to maintain cladribine in the complex. For example, in the case of γ-cyclodextrin, about 0.10 moles of γCD are required to maintain about 0.01 moles of cladribine in its saturated complex; Molar cladribine maintains its saturated complex. However, in the case of γCD, drug solubility increased significantly at higher concentrations of cyclodextrin; the slope of the line changed for approximately 0.15 molar concentrations of γCD, indicating that a 1:2 ratio of cladribine to cyclodextrin was formed. The complex, that is, 1 molecule of cladribine complexed with 2 molecules of γ-CD, which substantially surrounds and protects the cladribine molecule.

It is thought that at high cyclodextrin concentrations, 2 molecules of γ-CD hydrogen bond to each other and pack the cladribine molecule into the cavity between them. This is believed to be a stepwise process in which first a 1:1 complex is formed and then a second γ-CD molecule hydrogen bonds to the γ-CD in the 1:1 complex to form a 1:2 complex. Of course, mixtures of 1:1 and 1:2 complexes are often obtained, but it is advantageous that the 1:2 complex predominates. Thus, in the case of gamma-CD, about 0.20 molar concentration of cyclodextrin can maintain about 0.017 molar cladribine in its saturated complex. However, at higher cyclodextrin and drug concentrations, the amount of cyclodextrin required for a given amount of cladribine differed less between γCD and HPβCD, and γ-CD was more effective than HPβCD. Dissolve proportionally more cladribine. Since the 1:2 complex formed at a higher concentration of γCD is a stronger complex than the 1:1 complex, when such a 1:2 complex releases the drug in a body fluid at the mucosa in a saturated solution The cladribine of ® is less stable, ie has a higher thermodynamic activity than cladribine released from the 1:1 complex, favoring a stronger movement of the drug through the mucosa. Complexes with γCD are also advantageous because γCD is a natural cyclodextrin and thus presents less tissue relative toxicity. Moreover, in the case of solid oral dosage forms, it is believed that the 1:2 complex with γ-CD can better protect cladribine from gastric acid attack, because it can substantially surround the drug molecule with cyclodextrin, so it can Uniquely well suited for the purposes of the present invention.

Example 2 Preparation of cladribine-cyclodextrin complex

Part A: Cladribine was complexed with HPβCD or γCD by the following general method.

An excess aqueous suspension of cladribine and a concentrated solution of cyclodextrin (about 27% for γ-cyclodextrin; about 40% for HPβCD) were mixed with stirring at room temperature for about 9 hours. This will strike a balance. Excess uncomplexed cladribine that may be present is removed by filtration. To form a solid saturated cladribine-cyclodextrin complex, the aqueous cladribine-cyclodextrin solution was lyophilized prior to incorporation into solid buccal or oral tablets. The freeze-drying method comprises: the complex solution is rapidly dropped to a temperature of about -40°C to about -80°C for about 2 to 4 hours, preferably about 3 to 4 hours of freezing stage, for example, the temperature of about -45°C is maintained for about 200 minutes , followed by a primary drying stage at about -25°C for about 80-90 hours, typically at reduced pressure, followed by a secondary drying stage at about 30°C for about 15-20 hours.

The product prepared by the aforementioned general method can be analyzed by HPLC (using a Hypersil ODS 3 micron column and an acetonitrile based mobile phase with UV detection at 264 nm) to determine the weight ratio of cladribine to cyclodextrin in the final product. By methods known in the art including, for example, by inspection of appearance, total impurity content by HPLC, water content using a Karl Fischer titrator, solubility by standard methods, such as using a USP <711> Apparatus II apparatus and UV light at 264 nm Testing, checking content uniformity and quantitative determination of active ingredients by HPLC analysis can further characterize the final product formulation.

Part B:

By the general procedure described above, 2 batches of cladribine/cyclodextrin products were prepared as follows: FD02 with γ-CD and FD03 with HPβCD:

For each batch, purified water (585 ml for FD02; 575 ml for FD03) was dispensed into 1 liter glass bottles. Gamma-cyclodextrin (116 g) and 2-hydroxypropyl-β-cyclodextrin (115 g) were weighed and added slowly to the stirring water over 30 minutes. Cladribine (2.53 g for FD02; 2.76 g for FD03) was weighed into the respective stirred cyclodextrin solutions. Sonicate the solution for 20 min. The resulting clear solution was stirred at room temperature for 9 hours. The solution was filled into 100 ml lyophilization vials (20 ml solution/vial) and the filled vials were partially stoppered. Lyophilization consisted of: freezing at -45°C for approximately 3.3 hours, a primary drying stage at -25°C under a pressure of 100 mTorr for approximately 85.8 hours, and a secondary drying stage at 30°C for approximately 17.5 hours, as follows:

freeze drying cycle

The cladribine/cyclodextrin batches FD02 and FD03 prepared by the previous method were analyzed by HPLC (using a Hypersil ODS 3 micron column and an acetonitrile-based mobile phase with UV detection at 264 nm) and were empirically found to have The following characteristics:

Complex weight: weight weight ratio Cladribine: γ-CD 2.53g: 116.0g 1:46 Cladribine: HPβCD 2.76g: 115.0g 1:42

The product was analyzed by DSR and X-ray diffraction methods to determine any free cladribine in the lyophilized product. Importantly, the samples exhibited no transitions in the region of 210 °C to 230 °C, which is associated with the melting of crystalline cladribine. In both cases, no significant thermal activity was recorded in the range of 210 °C to 230 °C, indicating that the complexes obtained at the end of lyophilization did not have any significant amount of free crystalline cladribine, considering the analysis Sensitivity of the method (up to 3% w/w). This conclusion is also supported by the absence of peaks of crystalline cladribine in the X-ray diffraction traces of the 2 batches of complexes FD02 and FD03.

As noted above, these cladribine:cyclodextrin complexes have the following cladribine:cyclodextrin weight ratios: about 1:46 for cladribine:γ-cyclodextrin; Hydroxypropyl-beta-cyclodextrin, about 1:42. Cladribine:cyclodextrin weight ratios close to these values, eg, about 1:35 to about 1:50, are most desirable. These ratios can vary depending on the particular cyclodextrin used and the amount of cyclodextrin in the compounding solution, as well as the compounding temperature.

Example 3

Pharmacokinetic Studies

The bioavailability of cladribine when complexed with γCD or HPβCD was evaluated in the beagle retriever model. Data from this model are expected to be representative for human applications.

Saturated cladribine-cyclodextrin complexes FD02 and FD03 prepared as in Example 2, part B, were used for the preparation of oral and buccal tablets. The composite material and magnesium stearate were passed through a 18 mesh (0.9 mm) screen, mixed for 5 minutes, and compressed using a 10 mm punch. The 10 mm tablet has a slightly convex upper shape and a flat beveled lower shape. The production formula is as follows:

Table II, Part A

*This amount of complex contains approximately 5 mg cladribine/tablet.

Table II, Part B

Properties of the finished tablet Cladribine: γ-CD tablet RDT-0418/C Cladribine: HP-β-cyclodextrin tablet RDT-0418/D Average weight 237.0mg 217mg Hardness 4.0Kp 6.72Kp Brittle 0.5% 0.4% thickness 3.8mm 3.3mm disintegration time 8 minutes 8 minutes

Bioavailability and pharmacokinetic studies were performed in the beagle hound model as follows.

Outbred male beagle dogs (designated PM01-PM06) obtained from IDRI (Dunakeszi, Hungary) were given laboratory diet and water ad libitum. The same dogs were used throughout the study to minimize inter- and within-subject variability. Bioavailability and pharmacokinetic studies were performed as follows.

In the first experimental session, subjects were administered 5 mg cladribine (0.25 mg/ml in isotonic saline) intravenously. Blood samples were collected at various intervals over a 48-hour period. In the second experimental phase, half of the subjects received orally tablets containing saturated cladribine-γCD or -HPβCD complexes as described above. Over 48 hours, serial blood samples were collected. The third experimental phase repeated the second experimental phase, except that subjects who previously received gamma-cyclodextrin buccal tablets now received hydroxypropyl-beta-cyclodextrin buccal tablets, and the second phase of hydroxypropyl- Beta-cyclodextrin tablet recipients are now receiving gamma-cyclodextrin buccal tablets. Fourth and Fifth Experimental Phases Experimental phases 2 and 3 were repeated, except that the tablets were administered orally.

Cladribine levels in blood were detected by HPLC and LC/MS/MS methods. Pharmacokinetic analysis of data was performed using TopFit 2.0 pharmacokinetic and pharmacodynamic data analysis system. The results of the bioavailability studies for the control (intravenous) and cladribine-cyclodextrin complexes are shown in Tables III to VII and summarized in Table VIII.

The headers for the columns in Table III are defined as follows:

C _initial is the extrapolated value at the end of the bolus;

C _first is the concentration first measured 5 minutes after dose administration;

t1/2 terminal is the terminal elimination half-life;

AUD is the area under the measured data, integrated with the linear trapezoidal rule;

AUD _ext is the extrapolated area from the last measured time point to infinity;

AUC is AUD extrapolated to infinity;

CI _tot is the overall clearance (dose/AUC); and

MRT _tot is mean dwell time.

The headers for the columns in Tables IV to VII are defined as follows:

_Cmax is the measured peak concentration;

T _max is the time to C _max ;

t1/2 terminal is the terminal elimination half-life;

AUD is the area under the measured data, integrated with the linear trapezoidal rule;

AUD _ext is the extrapolated area from the last measured time point to infinity;

AUC is AUD extrapolated to infinity;

MRT _tot is the mean dwell time; and

F is the bioavailability expressed in %.

Peak areas, calibration curves, accuracy, precision values and concentrations were determined using Analyst Software 1.1 (PE SCIEX, Foster City, US). To calculate the mean and standard deviation, Excel 5.0 software was used. A calibration curve was fitted using the concentration ratios of analytes and internal standards versus their peak area ratios. Straight lines were fitted to the experimental points by weighted least squares linear regression analysis. The weighting scheme used was 1/concentration squared (pg/ml plasma).

At early time points after intravenous administration, plasma concentrations exceeded the upper limit of the calibration curve. A smaller amount of sample was thus re-injected to confirm linear detector response. Concentrations in excess of 100 ng/ml are acceptable since the standard/internal standard ratio remains the same in appropriate detector responses. For calculation of mean, standard deviation and %CV, Excel 5.0 software was used. Levels below the limit of quantitation were not accepted. Mean and standard deviation values were calculated for concentrations measured after intravenous administration only.

Table VIII

*: excluded from the mean (because the values obtained are highly abnormal compared to other objects)

**: excluded from the mean (because the subject swallowed the drug dosage form)

a: Excess cyclodextrin, about 10 times that used for the saturated complex.

The total amount of cyclodextrin in these studies was approximately 2.5 gm for 5 mg cladribine.

Pharmacokinetic analysis was performed based on the respective plasma concentration versus time curves. The mean and standard deviation of the parameters obtained from each data were calculated. The area under the plasma concentration-time curve (AUD) from 0 to the last measured concentration was calculated using the linear-trapezoidal rule. Using the endpoint regression line, the area extrapolated to infinity (AUCt _→∞ ) is calculated in the following way: AUCt _→∞ =C _cal c/ _λz

where C _calc represents the plasma concentration estimated from the regression line at the last sampling time point at which the measured concentration was greater than the limit of quantification, and _λz represents the rate constant calculated from the regression line.

By visual determination of the linear part of the semi-logarithmic curve, the points that determine the regression line (ie the final phase) are selected. The total area under the curve (AUC) was calculated by adding together the partial areas: AUC=AUD+AUC _t→∞ . AUC values were normalized with the actual dose administered in a particular period. To calculate bioavailability, divide the buccal/oral AUC/dose value by the intravenous AUC/dose value.

Individual plasma level-time profiles were obtained. Smaller inter-individual variability was found after intravenous administration. After a very rapid initial decrease, the uneliminated half-life of cladribine is approximately 10 hours. The mean total clearance was demonstrated to be 17ml/min/kg. During buccal administration of both formulations, the cladribine:γ-cyclodextrin complex had a longer dissolution period than the cladribine:HP-β-cyclodextrin complex. While both peak concentrations and absorption profiles showed high inter-individual variability after buccal and oral administration, total exposure values (AUC) showed much lower variability. The oral bioavailability was confirmed to be good: 50±3% and 45±5% for γ-cyclodextrin and hydroxypropyl-β-cyclodextrin complex, respectively. Oral bioavailability values are low: 37±10% for the γ-cyclodextrin complex and 30±4.5% for the hydroxypropyl-β-cyclodextrin complex.

The results of a further dog pharmacokinetic study comparing the gamma-cyclodextrin complex and mixture are shown in Table IX below. The "Oral Complex" column describes the absolute bioavailability results for 5 mg cladribine in 2.5 g gamma-cyclodextrin; this is approximately 10 times the amount of cyclodextrin in the saturated complex of 5 mg cladribine. This formulation is the same as in the "Oral Composition" column, except that a complex is prepared instead of just mixing the components. The results for "Oral Mixture" and "Oral Complex" are comparable, indicating that with such a large excess of cyclodextrin, complexes can form during dissolution, interfere with dissolution, and have a negative effect on bioavailability. The same dogs and the same experimental method were used as before. These results indicate that the use of cyclodextrin in excess is undesirable, i.e. substantially free of saturated cladribine beyond the minimum amount of cyclodextrin required to maintain substantially all of the cladribine in the complex. Drubine-cyclodextrin complexes provide enhanced bioavailability and reduced interpatient variability.

Table IX

*excluded from average

a: Excess cyclodextrin, about 10 times that used for the saturated complex. The total amount of cyclodextrin in these studies was approximately 2.5 gm for 5 mg cladribine.

The results of the aforementioned pharmacokinetic studies are shown in Figures 2-6.

Figure 2 shows the plasma profile of cladribine in dogs after a single 5 mg dose of the different formulations described above, where the data are mean ± standard deviation, 5-6 animals per group. Mean drug concentrations in plasma (pg/ml) were plotted against time (hours). Although each experiment was run for 48 hours, only the first 6 hours are represented in the figure; after 6 hours, most concentrations had returned to or approached baseline and were therefore not shown. The intravenous value (◇) was considered to result in 100% bioavailability and compared to the plasma levels of the oral and buccal forms. For the meaning of the logo, see the "Description of Drawings" above. In these experiments it was found that buccal formulations with saturated complexes of γ-cyclodextrin (*) and hydroxypropyl-β-cyclodextrin (x) were not as effective as oral formulations, which can be easily seen from Figure 2 out. The results for the 5 different oral formulations can be seen more easily with reference to Figures 3-5.

Figure 3 compares the intravenous formulation (♦), the oral saturated cladribine-γ-cyclodextrin complex formulation (●), and the oral saturated cladribine-hydroxypropyl-β-cyclodextrin complex formulation (▲) The plasma curve of (shown in Figure 2). Both oral formulations offer desirable characteristics.

Figure 4 compares oral saturated cladribine-γ-cyclodextrin complex formulations (●), oral capsules of cladribine with a physical mixture of 10-fold excess of γ-cyclodextrin (○) cladribine-γCD Oral capsules of the complex with 10-fold excess of γ-cyclodextrin (□) Plasma profile shown in Figure 2. It can be seen that an excess of cyclodextrin reduces the amount of cladribine in plasma, especially in the first 1 hour after administration.

Figure 5 compares oral saturated hydroxypropyl-β-cyclodextrin complex formulations (▲) and oral capsules of a physical mixture of cladribine and a 10-fold excess of hydroxypropyl-β-cyclodextrin (△) ( Shown in Fig. 2) plasma curve. Again it can be easily seen that excess cyclodextrin reduces the amount of cladribine in the complex. In this case, the reduction was seen in the first 2 hours after application.

Figure 6 illustrates the cumulative area under the curve (AUC) (pgxh/ml) for the 8 formulations shown in Figure 2 . Again, data are the mean of 5-6 animals per group.

The Figures thus illustrate what the data in Tables III to IX show, that a solid oral or transmucosal dosage form made substantially does not contain more than that required to maintain substantially all of the cladribine in the complex. A saturated cladribine-cyclodextrin complex with a minimal amount of cyclodextrin was able to enhance bioavailability with acceptable inter-patient variability.

The foregoing is considered as illustrative only of the principles of the invention. Moreover, since many modifications and changes will readily occur to those skilled in the art, the invention should not be limited to the exact construction and operation shown and described, and therefore all suitable modifications and equivalents that may be made are included in within the scope of the claimed invention.

Claims (27)

1. make the pharmaceutical composition of saturated cladribine-cyclodextrin complexes of containing of solid oral dosage form, described compositions is substantially devoid of and surpasses the cyclodextrin that will all basically cladribines maintains minimum required in the complex, wherein cyclodextrin is a gamma-cyclodextrin, HP-, hydroxypropyl-gamma-cyclodextrin, DM-, methylated at random beta-schardinger dextrin-, carboxymethyl-beta-cyclodextrin or sulfur butyl-beta-schardinger dextrin-.

2. according to the compositions of claim 1, wherein cyclodextrin is a gamma-cyclodextrin.

3. according to the compositions of claim 1, wherein cyclodextrin is a HP-.

4. according to the compositions of claim 2, wherein complex comprises 1: 2 cladribine: the gamma-cyclodextrin complex.

5. according to the compositions of claim 2 or 3, wherein the weight ratio of cladribine and cyclodextrin is 1: 35 to 1: 50.

6. according to the compositions of claim 2, wherein the weight ratio of cladribine and gamma-cyclodextrin is 1: 46.

7. according to the compositions of claim 3, wherein the weight ratio of cladribine and HP-is 1: 42.

8. according to each the compositions in the claim 1,2 and 3, wherein cladribine corresponding with the mol ratio of cyclodextrin be arranged in the point of cladribine on the phase solubility figure of the saturated complex of the cyclodextrin of variable concentrations.

9. compositions according to Claim 8, wherein cyclodextrin is a gamma-cyclodextrin, and this point is taken from and indicated the formation cladribine: the phase solubility figure part of 1: 2 complex of gamma-cyclodextrin.

10. saturated cladribine-cyclodextrin complexes is used for the application of administration with the solid oral dosage form of the reactive condition symptoms of treatment cladribine in preparation, described dosage form is substantially devoid of and surpasses the cyclodextrin that will all basically cladribines maintains minimum required in the complex, wherein the reactive disease of cladribine is selected from multiple sclerosis, rheumatoid arthritis, inflammatory bowel and leukemia, wherein cyclodextrin is a gamma-cyclodextrin, HP-, hydroxypropyl-gamma-cyclodextrin, DM-, methylated at random beta-schardinger dextrin-, carboxymethyl-beta-cyclodextrin or sulfur butyl-beta-schardinger dextrin-.

11. according to the application of claim 10, wherein the reactive disease of cladribine is selected from multiple sclerosis, rheumatoid arthritis and leukemia,

12. according to the application of claim 11, wherein the reactive disease of cladribine is a multiple sclerosis.

13. according to each the application in the claim 10,11 and 12, wherein cyclodextrin is a gamma-cyclodextrin.

14. according to each the application in the claim 10,11 and 12, wherein cyclodextrin is a HP-.

15. according to the application of claim 10, wherein the weight ratio of cladribine and cyclodextrin is 1: 35 to 1: 50.

16. according to the application of claim 13, wherein the weight ratio of cladribine and gamma-cyclodextrin is 1: 46.

17. according to the application of claim 14, wherein the weight ratio of cladribine and HP-is 1: 42.

18. according to the application of claim 13, wherein complex comprises 1: 2 cladribine: the gamma-cyclodextrin complex.

19. saturated cladribine-cyclodextrin complexes is used for improving the application of solid oral dosage form of the oral administration biaavailability of cladribine in preparation, described dosage form is substantially devoid of and surpasses the cyclodextrin that will all basically cladribines maintains minimum required in the complex, wherein cyclodextrin is a gamma-cyclodextrin, HP-, hydroxypropyl-gamma-cyclodextrin, DM-, methylated at random beta-schardinger dextrin-, carboxymethyl-beta-cyclodextrin or sulfur butyl-beta-schardinger dextrin-.

20. according to the application of claim 19, wherein cyclodextrin is a gamma-cyclodextrin.

21. according to the application of claim 19, wherein cyclodextrin is a HP-.

22. according to claim 19,20 or 21 each application, wherein the weight ratio of cladribine and cyclodextrin is 1: 35 to 1: 50.

23. according to the application of claim 20, wherein the weight ratio of cladribine and gamma-cyclodextrin is 1: 46.

24. according to the application of claim 21, wherein the weight ratio of cladribine and HP-is 1: 42.

25. according to the application of claim 20, wherein complex comprises 1: 2 cladribine: the gamma-cyclodextrin complex.

26.1: 2 cladribines: gamma-cyclodextrin complex.

27.1: 1 cladribine: gamma-cyclodextrin complex and 1: 2 cladribine: the mixture of gamma-cyclodextrin complex, wherein 1: 2 complex is main.

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