Title of Invention

A METHOD FOR THE PREPARATION OF FENOFIBRATE-CYCLODEXTRIN INCLUSION COMPLEX

Abstract

A method for the preparation of fenofibrare-cyclodextrin inclusion complex comprising: Formula 1 a) wetting cyclodextrin or cyclodextfin derivative having an average particle size of 10 m to 250 m with a solvent selected from the group consisting of water, acetone, C1-C4 aliphatic alcohol other than ethanol or rectified spirit, and mixtures thereof, in an amount sufficient to form a semisolid mixture; b) mixing the resulting semisolid mixture with micronized fenofibrate of the formula 1 having an average particle size of 1 m to 40 n thereby forming a mixed fenofibrate-cyclodextrin inclusion complex; and c) drying said mixed inclusion complex at 40°C to 80°C, wherein the molar ratio of fenofibrate to cyclodextrin or cyclodextrin derivative is 1 : 0.5 to 1:4' and the molar ratio of the solvent to cyclodextrin or cyclodextrin derivative is 1 : 1.5 to 1:4.

Full Text

F O R M 2 THE PATENTS ACT 1970 As amended by the Patents (Amendment) Act, 2002 COMPLETE SPECIFICATION (See Section 10; Rule 13) TITLE A method for the preparation of fenofibrate-cyclodextrin inclusion complex APPLICANTS USV Limited, BSD Marg, Govandi, Mumbai 400088, Maharashtra, India, an Indian Company INVENTORS Dr Gidwani Suresh Kumar and Singnurkar Shashikant Purushottam, USV Limited, BSD Marg, Govandi, Mumbai 400088, Maharashtra, India, both Indian Nationals The following specification particularly describes the nature of this invention and the manner in which it is to be performed ORIGINAL 519/MUMNP/2004 GRANATED 4-2-2004 This invention relates to a method for the preparation of fenofibrate-cyclodextrin inclusion complex. This invention also relates to a method for the preparation of a pharmaceutical formulation of fenofibrate-cyclodextrin inclusion complex. CROSS-REFERENCE TO COPENDING PATENT APPLICATION The present application claims the benefit of US provisional application No 60/382,997, filed on May 23, 2002 which is incorporated herein by reference in its entirety. BACKGROUND OF THE INVENTION Fenofibrate corresponds to the nomenclature of 2-[4-(4-chlorobenzoyl)phenoxy]-2-methyl propionate and is insoluble in water. Fenofibrate has the formula: With an aqueous solubility of less than 0.5 mg/liter, the dissolution of fenofibrate likely represents the rate limiting steps before the drug becomes adsorbed in the body. Fenofibrate is a neutral, lipophilic compound having a lipid water distribution coefficient, log P = 5.24, and is a well-known hypolipemiant from the family of fibrates, which is commercially available in various doses (100 and 300 mg for example Secalip® ) but in a form leading to poor bioavailability of the active ingredient. Bioavailability is the degree to which or rate at which a drug or other substance is absorbed or becomes available at the site of physiological activity after administration. Drugs having a high dissolution profile have a higher bioavailability than drugs that have a low dissolution profile. A hypolipemiant is a drug that reduces the amount of lipids (fats) in the blood. Lipophilic is a substance having affinity for, tending to combine with, or capable of dissolving in lipids. Fenofibrate is both hypolipemiant and lipophilic. Due to its poor hydrosolubility (solubility in water), however, fenofibrate is poorly absorbed in the digestive tract and consequently its bioavailability is incomplete, irregular and often varies from one person to another. As a result, commercially available doses must be of higher strength and require application several times a day. EPA-0330532 to Curtet et al., describes a method for improving bioavailability of fenofibrate by co-micronizing fenofibrate with a surfactant, for example sodium lauryl sulphate, in order to improve fenofibrate solubility. According to this invention, 200 mg of co-micronized fenofibrate was found to be bioequivalent to 300 mg of non-mi cronized fenofibrate. However, this improvement in dissolution and bioavailability is not satisfactory because the technique of co-micronizing with a surfactant still leads to incomplete dissolution of fenofibrate. US 6,277,405 B 1 to Stamm, et al, describes a fenofibrate pharmaceutical composition having enhanced bioavailability. It comprises spraying a suspension of a micronized fenofibrate with hydrophilic polymer, for example, polyvinyl pyrrolidone onto an inert carrier. Following granulation, the granulate formed consists of crystals of, for example, lactose, which are isolated and particles of micronized fenofibrate and PVP adhere to the crystal surface. The granulate obtained is compressed to form tablets. This composition has been shown to have a dissolution of at least 10% in 5 minutes, 20% in 10 minutes, 50% in 20 minutes and 75% in 30 minutes as measured by using the rotating blade method at 75 rpm, in a dissolution medium constituted by water with 2% by weight polysorbate 80 or with 0.025 M sodium lauryl sulphate. Although the composition described in the '405 patent appears to show improved bioavailability, its method of preparation is complex and expensive. For example, the process described by Stamm et al. involves spray coating of fenofibrate with polyvinylpyrrolidone.onto an inert carrier. This process not only involves the material loss of fenofibrate but also requires expensive equipment such as a fluidized bed coater / granulator that is difficult to scale up for a commercial product. US 6,294,192 To Patel, et al, describes triglyceride free compositions and methods for improved delivery of hydrophobic therapeutic agent, for example fenofibrate. Prepared by simple physical mixing, the compositions include a hydrophobic therapeutic agent and a carrier, where the carrier is formed from a combination of a hydrophilic surfactant and a hydrophobic surfactant. Upon dilution with an aqueous solvent, the composition forms a clear aqueous dispersion of the surfactant containing a hydrophobic therapeutic agent. Patel et al. also refer to fenofibrate as one of the hydrophobic therapeutic agent but do not provide any bioavailability improvement data on fenofibrate. The carrier described in Patel et al. further comprises cyclodextrin or cyclodextrin derivatives as an additional solubilizer to enhance the solubility of the hydrophobic therapeutic agent and not as the carrier itself. Further, Patel et al. do not provide any information or data for the use and effect of such solubilizers and their concentrations. By gently mixing or shaking the cyclodextrin with the carrier, the drug employed in the compositions of Patel et al. gains only marginal improvement in solubility (dissolution) and/or bioavailability. This invention provides an inclusion complex of fenofibrate with cyclodextrin, the complex having enhanced bioavailability as compared to either fenofibrate alone or a suspension of a micronized fenofibrate with hydrophilic polymer, such as PVP. As such, the present invention overcomes the limitations still existing in available fenofibrate products so as to improve the dissolution profile, improve absorption characteristics improve bioavailability of fenofibrate and reduce the dose . required for administration to attain a desired effect as compared to that for a fenofibrate pharmaceutical composition that is not part of a complex with cyclodextrin. Thus, there is still a need to provide fenofibrate pharmaceutical compositions and dosage forms having enhanced bioavailability where the dissolution of fenofibrate in the body is increased to a level of 100% within a short period of time after administration in comparison to a level of dissolution that fenofibrate has by itself, before it forms an inclusion complex with cyclodextrin. That is, the fenofibrate pharmaceutical composition has a characteristic that allows a dosage form of the inclusion complex of fenofibrate with cyclodextrin to be completely dissolved within a short time after administration. SUMMARY OF THE. INVENTION An aspect of the present invention resides in providing an immediate release pharmaceutical composition comprising an inclusion complex of fenofibrate with cyclodextrin which complex shows rapid and complete dissolution of fenofibrate, resulting into enhanced bioavailability. Another aspect of the invention resides in a method for the preparation of an inclusion complex of fenofibrate with cyclodextrin which is efficient and economical, simple and less time consuming than conventional techniques, and which is suitable for manufacture of a product on commercial scale. Preferably, the complex of fenofibrate with cyclodextrin renders the active drug fenofibrate highly soluble and/or rapidly dissoluble in physiological fluids including gastric fluid. Dissolution levels of fenofibrate can reach from about 80% to about 100% in a relatively short amount of time from about 10 to about 30 minutes, preferably from about 10 to about 20 minutes. A further aspect of the present invention is to provide pharmaceutical compositions of an inclusion complex of fenofibrate with cylodextrin, which renders the active drug fenofibrate highly soluble and/or rapidly dissoluable and safe for use as a pharmaceutical. Still another aspect of the present invention is to provide a method for the preparation of pharmaceutical compositions having an inclusion complex of fenofibrate with cyclodextrin, which results in a product safe for use as a pharmaceutical and which renders the active drug fenofibrate highly soluble in physiological as well as in gastric fluid pH. Other improvements which the present invention provides over the prior art will be identified as a result of the following description which sets forth the preferred embodiments of the present invention. The description is not in any way intended to limit the scope of the present invention, but rather only to provide a working example of the presently preferred embodiments. The scope of the present invention will be pointed out in the appended claims. BRIEF DESCRIPTION OF THE DRAWING Fig 1A is a DSC thermogram of fenofibrate Fig 1B is a DSC thermogram of beta cyclodextrin. Fig 1C is a DSC thermogram of a physical mixture of fenofibrate with beta cyclodextrin. Fig 1D is a DSC thermogram of an inclusion complex of fenofibrate with beta cyclodextrin. DETAILED DESCRIPTION OF THE INVENTION According to the present invention there is provided a inclusion complex of 2-[4-(4-chlorobenzoyl)phenoxy]-2-methyl propanoic acid, commonly known as fenofibrate of the formula 1 below with cyclodextrin. In the inclusion complex of the invention, fenofibrate is in micronized form of average particle size from about 1 m to about 40 n, preferably from about 2 m to about 20 m and cyclodextrin has an average particle size of from about 10 m to about 350 n, preferably from 10 m to about 250 m. In the inclusion complex of the present invention the molar ratio of fenofibrate to cyclodextrin is from about 1 : 0.5 to about 1:4. According to the invention there is provided a method for the preparation of fenofibrate-cyclodextrin inclusion complex comprising: a) wetting cyclodextrin or cyclodextrin derivative having an average particle size of 10 m to 250 m with a solvent selected from the group consisting of water, acetone, C1-C4 aliphatic alcohol other than ethanol or rectified spirit, and mixtures thereof, in an amount sufficient to form a semisolid mixture; b) mixing the resulting semisolid mixture with micronized fenofibrate of the formula 1 Formula 1 having an average particle size of 1 m to 40 n thereby forming a mixed fenofibrate-cyclodextrin inclusion complex; and c) drying said mixed inclusion complex at 40°C to 80°C, wherein the molar ratio of fenofibrate to cyclodextrin or cyclodextrin derivative is 1 : 0.5 to 1:4 and the molar ratio of the solvent to cyclodextrin or cyclodextrin derivative is 1 : 1.5 to 1:4. According to the present invention there are also provided a method for the preparation of a pharmaceutical formulation of fenofibrate-cyclodextrin inclusion comp'ex comprising mixing an inclusion complex of fenofibrate of the formula 1 Formula 1 and cyclodextrin with pharmaceutically acceptable excipient, wherein said fenofibrate is in micronized form having an average particle size of 1 m to 40 n, said cyclodextrin is in an average particle size of 10 m to 250 m and the molar ratio of fenofibrate to cyclodextrin is 1 : 0.5 to 1 : 4. According to the invention there is also provided a method for the preparation of a pharmaceutical composition of a cyclodextrin inclusion complex of fenofibrate in combination with pharmaceutically acceptable excipients, wherein the fenofibrate is in a micronized form having an average particle size of 1.0 m to 40 n and cyclodextrin or cyclodextrin derivative is having an average particle size of 10 n to 250 m, and the molar ratio of fenofibrate to cyclodextrin or cyclodextrin derivative is 1 : 0.5 to 1 : 4, which method comprises mixing the inclusion complex with .the excipients, and if desired, converting the resulting mixture into a desired pharmaceutical dosage form. Preferably the average particle sizes of fenofibrate can be from about 2 m to about 20 m. Cyclodextrin useful in the inclusion complex of the present invention include without limitation alpha cyclodextrin, beta cyclodextrin, gamma cyclodextrin, alkyl, hydroxy alkyl derivatives or mixtures thereof. Preferably cyclodextrin may be beta cyclodextrin, gamma cyclodextrin, hydroxypropyl beta cyclodextrin randomly methylated beta cyclodextrin, or mixtures thereof. As used herein, "cyclodextrin" refers to a-1,4 linked cyclic oligosaccharides composed of glucopyranose units. The number of glucoses forming the ring is not limited at all and a, (3- and y-cyclodextrins having 6 to 8 glucoses are commercially available. The cyclodextrin may have a branch. The hydroxyl group(s) in cyclodextrin may be modified; cyclodextrins having such a modifying group are included in the "modified derivatives of cyclodextrin". Illustratively, the modification includes alkylation such as methylation, hydroxyalkylation such as . hydroxypropylation, esterification such as acetylation or succinylation, glucosylation, carboxymethyl etherification, phosphoric esterification, sulfobutyl etherification and carboxymethylation. These modified derivatives are described in Loftsson et al., J. Pharmaceu. Sci., 85 : 1017 (1996); Stella et al., Pharmaceutical Res., 14 : 556 (1997). Preferably water or isopropyl alcohol can be used as a solvent, either alone or in combination with each other. Whenever combinations are used, the water and isopropyl alcohol can be in a ratio of from about 1:9 to about 9 : 1, preferably from about 1 : 7.5 to about 7.5 : 1. The inclusion complex' can be freeze dried or spray dried or dried by low temperature vacuum evaporation in a tray dryer or dried in fluidized bed dryer. Preferably the mixed inclusion complex may be dried in tray dryer. Preferably drying is carried out at temperature from about 40°C to about 60°C. The molar ratio of fenofibrate to cyclodextrin or cyclodextrin derivative is preferably from about 1 : 1 to about 1 : 2. The molar ratio of solvent to cyclodextrin or cyclodextrin derivative can be preferably be about 1 : 2.4. Useful excipients for the fenofibrate - cyclodextrin inclusion complex include without limitations lactose, microcrystalline cellulose, calcium carbonate, starch, colloidal silicone dioxide, sodium starch glycolate, talc, magnesium stearate, polyvinyl pyrrolidone, mixtures thereof, and/or other excipients known in the art. The fenofibrate - cyclodextrin inclusion complex can be administered as pharmaceutical formulation in form of tablet or in the form of granules inside a capsule. Tablets and capsules can be prepared by mixing the dried and sized fenofibrate complex with pharmaceutically acceptable excipients and compressing the resulting blend into tablets or filling it into capsules. Tablets and capsules are prepared in accordance with the invention by employing the same techniques that are well known in the art for forming tablets and capsules composed of other types of ingredients. If, desired, the compositions may be encapsulated in a hard or soft gelatin capsule, a starch capsule or an enteric coated capsule. The term "enteric coated capsule" as used herein means a capsule coated with a coating resistant to acid, especially gastric acid. The unit dose of fenofibrate contained in each tablet can be from about 100 mg to about 300 mg. The unit dose of fenofibrate in each capsule can also be from about .100 mg to about 300 mg or the amount of the unit doses may be higher or lower as determined . by a physician for use in administration to a patient in view of the patient's age, weight, and response to such administration. If desired, the capsule or tablet may be coated to enhance its appearance. In a preferred embodiment, tablets or capsules including the fenofibrate - cyclodextrin inclusion complex of the present invention can be prepared by a method which comprises : (i) wetting cyclodextrin or cyclodextrin derivative of particle sizes from about 10 m to almost 250 n with a pharmaceutical acceptable solvent such as water, acetone and/or C1 -C4 aliphatic alcohol (other than ethanol and other than rectified spirit) at room temperature to form a semisolid mixture; (ii) mixing the resulting semisolid mixture with fenofibrate of micronised particle sizes of from about 1 m to about 40 m to form a mixed fenofibrate - cyclodextrin inclusion complex; (iii) drying the mixed fenofibrate - cyclodextrin inclusion complex at from about 40°C to about 80°C to form the fenofibrate-cyclodextrin inclusion complex, the molar ratio of fenofibrate to cyclodextrin or cyclodextrin derivative being 1 : (0.5 - 4), and the molar ratio of solvent to cyclodextrin or cyclodextrin derivative being 1 : (1.5 -4); (iv) mixing the dried and sized fenofibrate complex with pharmaceutically acceptable excipients, and compressing the resulting blend into tablets or filling it into capsules. The fenofibrate - cyclodextrin inclusion complex of the invention is unreported hitherto and is novel. According to the invention, a the fenofibrate is in micronized form having an average particle size suitable for interaction with cyclodextrin. The micronized fenofibrate has increased surface area for better interaction with cyclodextrin or cyclodextrin derivatives. The solvent used is in considerably less quantity then previously known in the art. For example, a solvent to cyclodextrin molar ratio of from about 1 : 1.5 to about 1:4 is sufficient to wet the cyclodextrin and result in a semisold reaction mixture. The semisolid mixture of cyclodextrin is amenable to shear mixing with fenofibrate because of which it has been possible to obtain an inclusion complex in which the .fenofibrate is uniformly distributed and dispersed in cyclodextrin matrix. The shear mixed inclusion complexes prepared by the method of the invention show rapid and high aqueous solubility of fenofibrate. For example, the shear mixed inclusion complexes show a 95% dissolution at physiological pH of 6.8 within 15 minutes and 100% dissolution in within 30 minutes. 70% dissolution in neutral pH of water within 30 minutes and 45% dissolution in pH of 1.2 (gastric fluid) within 30 minutes. Shear mixing is provided by methods well known in the art, for example by using a high shear mixer as manufactured by Diosna Mixer, West Germany or its equivalent. The following experimental examples are illustrative of the best mode of the invention but not limited to the scope thereof. All the materials used in the examples below are commercially readily available. Example 1 The purpose of this example was to prepare of an inclusion complex of fenofibrate and beta cyclodextrin. Beta cyclodextrin (504 gm) having an average particle size from about 10 m to about 70 m was mixed with 216 ml of demineralised water. The water : beta cyclodextrin ratio was 1 : 2.33. The reaction mixture was mixed in a suitable high shear. mixer available from Diosna Mixer, West Germany or its equivalent to obtain a semisolid mixture. To the semisolid beta cyclodextrin mixture, fenofibrate (160 gm) milled to an average particle size of from about 2 n to about 40 m was added and mixed in a high shear mixer for 1 hour. The fenofibrate : beta cyclodextrin molar ratio was 1:1. The resulting semisolid mass was dried at from about 40°C to about 60°C to obtain a solid inclusion complex of fenofibrate with beta cyclodextrin. EXAMPLE 2 An inclusion complex of fenofibrate and beta cyclodextrin was prepared according to a procedure analogous to that of Example 1. A mixture of isopropyl alcohol (80 ml) with water (120 ml) was used instead of demineralised water. The mixture of isopropyl alcohol and water was mixed with 504 gm of beta cyclodextrin to obtain an inclusion complex having a molar ratio of fenofibrate : beta cyclodextrin of about 1:1. The molar ratio of isopropyl alcohol with water mixture to beta cyclodextrin was 1 : 2.52. EXAMPLE 3 The procedure of Example 1 was followed using beta cyclodextrin (1008 gm) to obtain an inclusion complex which had a molar ratio of fenofibrate : beta cyclodextrin of 1 : 2 and a molar ratio of water to beta cyclodextrin of 1 : 2.33. EXAMPLE 4 The procedure of Example 1 was followed using hydroxypropyl beta cyclodextrin (670 gm) as manufactured by Cerestar Inc., USA to obtain an inclusion complex having a molar ratio of fenofibrate : hydroxypropyl beta cyclodextrin of 1 : 1 and a molar ratio of water to hydroxypropyl beta cyclodextrin of 1 : 3.72. EXAMPLE 5 The procedure of Example 1 was followed using gamma cyclodextrin (575 gm) (Cerestar Inc., USA) to obtain an inclusion .complex wherein the molar ratio of fenofibrate : gamma cyclodextrin was 1 : 2 and the molar ratio of water : gamma cyclodextrin ratio was> 1 : 2.21. EXAMPLE 6 The procedure of Example 1 was followed using randomly methylated beta cyclodextrin (590 gm) (Cerestar Inc., USA) to obtain an inclusion complex having a molar ratio of fenofibrate : gamma cyclodextrin of 1:1, and a ratio of water : gamma cyclodextrin of 1 : 2.10. EXAMPLE 7 The procedure of Example 1 was followed using isopropyl alcohol (230 ml) (MERCK KgaA, Germany) instead of demineralized water to obtain an inclusion complex. The isopropyl alcohol : beta cyclodextrin ratio was 1 : 2.19. The fenofibrate : beta cyclodextrin molar ratio was 1:1. EXAMPLE 8 The procedure of Example 9 was followed using isopropyl alcohol (460 ml) and beta cyclodextrin (1008 gm) to obtain an inclusion complex wherein the molar ratio of fenofibrate : beta cyclodextrin was 1 : 2, and the molar ratio of isopropyl alcohol : beta cyclodextrin was 1 : 2.19. EXAMPLE 9 The procedure of Example 6 was followed using hydroxypropyl beta cyclodextrin (670 gm) (Cerestar Inc, USA) and isopropyl alcohol. The resulting inclusion complex had a molar ratio of fenofibrate : hydroxypropyl beta cyclodextrin of 1:1, and a molar ratio of isopropyl alcohol: hydroxypropyl beta cyclodextrin of 1 : 3.72. EXAMPLE 10 A pharmaceutical composition in tablet form comprising 160 mg of fenofibrate was prepared by homogeneously mixing the inclusion complex of Example 1 with the excipients set forth in Table 1 below : TABLE 1 The ingredients set forth in Table .1 above are easily commercially available. Subsequently, the resulting pharmaceutical composition was directly compressed into tablets by methods well known in the art. For example, the tablet can be obtained on an alternating compression medicine (e.g. Korsch EKO) or a rotary machine (e.g. Fette Perfecta 2). EXAMPLE 11 The fenofibrate tablets obtained in Example 13 were film coated with a film coating having the composition set forth in Table 2 below: TABLE 2 The above ingredients are easily commercially available. To coat the fenofibrate tablets, film coating procedures well known in the art were used. Tablets were coated in an Accela Coater by spraying the coating solution of the above composition at a flow rate of about 40 to about 80 ml per minute and a pressure of from about 4 to about 6 Kg / square cm. During coating the tablet bed temperature was kept at from about 35°C to about 45°C with air blower under exhaust throughout the coating process. EXAMPLE 12 A pharmaceutical composition in capsule form comprising 160 mg of fenofibrate was prepared by homogeneously mixing the inclusion complex of Example 1 with the additives set forth in Table 3 below, before being filled into hard gelatin capsule of size 0, according to methods well known in the art. All ingredients listed below are easily commercially available from services as listed in Table 1. Table 3 Ingredients Contents in Tablet Inclusion complex of Example 1 664 mg Microcrystalline cellulose 32 mg Sodium starch glycolate 12 mg Talc 8 mg Crosspovidone 12 mg Colloidal silicone dioxide 4mg Magnesium stearate 10 mg EXAMPLE 13 160 gm of fenofibrate was mixed with 504 gm of beta cyclodextrin to provide a mixture containing 160 mg of fenofibrate per 664 mg of mixture wherein the molar ratio of fenofibrate : beta cyclodextrin was 1:1. EXAMPLE 14 In this example, the inclusion complex of Example 1 was characterized by high pressure liquid chromatography (HPLC) and differential scanning calorimetry (DSC). A. Quantitative determination of fenofibrate form inclusion complex by HPLC The potency of inclusion complex was calculated by HPLC with the following parameters 'as listed in Table 4 below: TABLE 4 The retention of fenofibrate was found to be 12.5 minutes for 32 mg of the inclusion complex of Example 1 which contained 5.01 mg of fenofibrate. This assay level proved that fenofibrate was uniformly dispersed through out the inclusion complex. B. Differential Scanning Calorimetry Study Thermogram of fenofibrate, beta cyclodextrin, a physical mixture of fenofibrate and beta cyclodextrin in a molar ratio 1 : 1 and the fenofibrate - beta cyclodextrin inclusion complex of the invention were as shown in figures 1A, 1B, 1C and 1D respectively. The thermograms were taken with Mettler TC11K- DSC, manufactured by Mettler Instruments AG, Switzerland. The peak at 80.1°C in Figure 1A was due to the melting of fenofibrate. Figure 2B showed an endothermic peak at ' 303.3°C corresponding to beta cyclodextrin and one peak at 96°C due to themoisture content of beta cyclodextrin. The physical mixture showed endothermic peak of both fenofibrate at 79.8°C and beta cyclodextrin at 299.9°C as in Figure 1C. The inclusion complex showed an drastic reduction in the intensity of the fenofibrate peak at 79.4°C as in Figure ID, indicating the formation of inclusion complex. EXAMPLE "l 5 In this example, in-vitro dissolution studies of the fenofibrate inclusion complexes of the invention and fenofibrate (micronized form) were performed using the rotating blade method at 75 rpm according to the USP24, in a dissolution medium constituted by water with 0.025 M sodium lauryl sulphate and water with 2% by weight polysorbate - 80. The results were as shown in Table 5 below: WE CLAIM 1. A method for the preparation of fenofibrare-cyclodextrin inclusion complex comprising: Formula 1 a) wetting cyclodextrin or cyclodextfin derivative having an average particle size of 10 m to 250 m with a solvent selected from the group consisting of water, acetone, C1-C4 aliphatic alcohol other than ethanol or rectified spirit, and mixtures thereof, in an amount sufficient to form a semisolid mixture; b) mixing the resulting semisolid mixture with micronized fenofibrate of the formula 1 having an average particle size of 1 m to 40 n thereby forming a mixed fenofibrate-cyclodextrin inclusion complex; and c) drying said mixed inclusion complex at 40°C to 80°C, wherein the molar ratio of fenofibrate to cyclodextrin or cyclodextrin derivative is 1 : 0.5 to 1:4' and the molar ratio of the solvent to cyclodextrin or cyclodextrin derivative is 1 : 1.5 to 1:4. 2. The method according to claim 1, wherein the fenofibrate is in micronized form having an average particle size of 2 n to 20 j m. 3. The method according to claim 1 or 2, wherein the solvent is water, isopropyl alcohol or mixtures thereof, wherein the molar ratio of water to alcohol is 1 : 9 to 9:1. 4. The method according to any one of claims 1 o 3, wherein the cyclodextrin of the inclusion complex is beta cyclodextrin, gamma cyclodextrin, hydroxypropyl beta cyclodextrin, randomly methylated beta cyclodextrin or mixtures thereof. 5. The method according to any one of claims 1 to 4, wherein the molar ratio of fenofibrate to cyclodextrin is 1 : 0.5 to 1 : 3. 6. A method for the preparation of a pharmaceutical formulation of fenofibrate-cyclodextrin inclusion complex comprising mixing an inclusion complex of fenofibrate of the formula 1 Formula 1 and cyclodextrin with pharmaceutically acceptable excipient, wherein said fenofibrate is in micronized form having an average particle size of 1 m to 40 said cyclodextrin is in an average particle size of 10to 250 m and the molar ratio of fenofibrate to cyclodextrin is 1 : 0.5 to 1: 4. 7. The method according to claim 6, wherein said fenofibrate is in a micronized form having an average particle size of 2 to 20 8. The method according to claim 7, wherein said cyclodextrin of the inclusion complex is beta cyclodextrin, gamma cyclodextrin, hydroxpropyl beta cyclodextrin, randomly methylated beta cyclodextrin or mixtures' thereof. 9. The method according to claim 7 or 8, wherein the molar ratio of fenofibrate to cyclodextrin is 1 : 1 to 1:2. 10. The method as claimed in any one of claims 7 to 9, wherein the pharmaceutical formulation is in tablet form. 11. The method as claimed in any one of claims 7 to 9 wherein the pharmaceutical formulation is in capsule form. Dated this 21st day of May 2003 (Jose M A) of Khaitan & Co Agent for the Applicants

Documents:

519-mum-2003 cancelled pages(4-2-2004).pdf

519-mum-2003 claims(granted)-(4-2-2004).pdf

519-mum-2003 correspondence(ipo)-(13-4-2007).pdf

519-mum-2003 correspondence1(15-7-2003).pdf

519-mum-2003 correspondence2(6-6-2006).pdf

519-mum-2003 form 1(22-5-2003).pdf

519-mum-2003 form 13(10-9-2003).pdf

519-mum-2003 form 19(15-7-2003).pdf

519-mum-2003 form 2(granted)(4-2-2004).pdf

519-mum-2003 form 26(10-9-2003).pdf

519-mum-2003 form 26(22-5-2003).pdf

519-mum-2003 form 3(19-2-2004).pdf

519-mum-2003 form 3(22-5-2003).pdf

519-mum-2003 form 5(13-12-2004).pdf

519-mum-2003 form 8(10-6-2003).pdf

519-mum-2003 form 8(16-6-2003).pdf

519-mum-2003 form 8(4-2-2004).pdf

519-mum-2003 petition under rule 137(13-12-2004).pdf

519-mum-2003-claims(granted)-(4-2-2004).doc

519-mum-2003-form 2(granted)-(4-2-2004).doc