IL111723A - Nimesulide salt/cyclodextrin inclusion complexes, process for their preparation and pharmaceutical compositions containing them - Google Patents

Abstract

Antiinflammatory and analgetic highly soluble inclusion complexes of nimesulide alkali and alkaline earth metal salts of the formula where A stands for an alkali and alkaline earth ion with cyclodextrins and cyclodextrin derivatives. 3096 ח' בטבת התשס" ב - December 23, 2001

Description

111723/2 NIMESULIDE SALT CYCLODEXTRINE INCLUSION COMPLEXES, PROCESS FOR THEIR PREPARATION AND PHARMACEUTICAL COMPOSITIONS CONTAINING THEM EUROPHARMACEUTICALS S.A.

CYCLOLAB LTD. - 2 - 111723/2 The invention relates to highly soluble, physiologically acceptable inclusion complexes of nimesulide- salts with cyclodextrins, to the preparation thereof, and to pharmaceutical compositions containing the same.

More particularly the invention relates to inclusion complexes of nimesulide alkali and alkaline earth salts of general formula (I) with cyclodextrins and cyclodextrin derivatives.

In this specification in the general formula A N - so2Me -A always stands for an alkali and alkaline earth ion.

NiroeEulide [ 4-nitro-2-phenoxy-methane-sulfonanilide J is known to ^be a potent non-steroidal antiinflammatory drug successfully used for tlve treatment of different painful inflammatory conditions, rheumatoid arthritiB and it possesses antipyretic activities too: (Belgian Patent N* 001812). Solutions of nimesulide sodium salts were prepared from nimesulide with sodium carbonate in acetone and they were used without isolation as intermediates to prepare N-substituted nimesulide derivatives (Belgian Patent N* 801812). Probably due to the high pH value of their solutions the nimesulide alkali and alkaline earth salts were not used practically ae pharmaceuticals. Recently it has been confirmed that based on its mechanism of action in pain relief, nimesulide can be also considered to represent a new type of useful analgesic agents. In case of such drugs a quick onset of action of the. orally administered formulation is a very important factor. 7 From patent W/O 91/17^4 there are known certain nimesulide complexes. However the solubility of said complexes is much lower than those of the present invention.

Compared to other non-steroidal antiinflammatories, nimesulide has a favorable therapeutic index, minimal acute gastrointestinal toxici^p. and shows good general tolerability . It is chemically different from other drugs of its class, because its functional acidic group is a sulfonanilide moiety.

Nimesulide is a very hydrophobic drug substance practically insoluble in water, its aqueous solublity is about o.oi mg/mi at room temperature. The very poor aqueous solubility and wettability of the drug present problems, for the preparation of pharmaceutical formulations with good release and non-variable bioavailability, To overcome the disadvantages connected with the very poor aqueous solubility and wettability the increase of aqueous solubility is an essential aim.

Nimesulide is a weak acid type compound therefore its aqueous solubility in acidic medium, e.g. at the pH of the gastric juice is particularly poor. Orally administered nimesulide is likely to be absorbed only in the lower part of the gastrointestinal tract, probably this explains the rather protracted onset of its biological effect.

Co plexation of nimesulide with cyclodextrins is described preferably with β-cyclodextrin in 1:1 molar ratio whereby faster absorption and higher plasma levels of nimesulide are shown in animal tests as compared with administration of nimesulide per se (Patent Applicat and DE 4116659).

For solid complex preparation three different known methods are exemplified: a. precipitation from water and organic solvent mixture by shaking overnight, the preferred solvent being methylene-chloride, b. freeze- or spray- drying from homogeneous aqueous ammonium hydroxide solution. c. stirring in aqueous suspension for several days at 60 °C and isolating the complex by evaporation under reduced pressure.

Method a. is not acceptable for preparation of CD complexes for pharmaceutical purposes. All organic solvents form more or less stable complexes with cyclodextrins. Inclusion of methylene chloride by β-cyclodextrin is inevitable in this case, consequently the product might contain a considerable amount of toxic chlorinated solvent. This can not be removed completely even by heating in vacuo at elevated temperature for hours, it will be released only upon dissolution e.g. in the gastric juice. Method c. is the oldest known method for preparation of drug/cyclodex-trin-complexes, but the long stirring time, with the concomitant degradation makes this process technically obsolete. Method b. seems to be the best, however it is difficult to completely remove ammonia during the freeze-drying procedure.

In the said Patent Application no data are given about the attainable solubility enhancement of nimesulide with BCD or the dissolution behaviour of the complexes prepared by the three different methods described in the Patent Application.

It can be concluded that both pH alteration towards the alkaline region and complexation with BCD can enhance the solubility of nimesulide. BCD alone shows qnly a very moderate (about 5-fold) solubility enhancing effect which means 0.05 - 0.06 mg/ml dissolved nimesulide in a saturated agueous BCD solution. However, significantly higher increase in solubility can be achieved only at pH beyond the physiologically acceptable values.

The object of the present invention was to prepare highly soluble, physiologically acceptable inclusion complexes comprising salt nimesulide / and cyclodextrins . Another object of the invention was to provide efficient method(s) for producing said complexes having the said solubility or redissolving properties.

One object of the present invention are the new inclusion complexes of nimesulide alkali and alkaline earth salt of general formula (I) with cyclodextrins and cyclodextrin derivatives. These new products ensure a considerable 200-600 fold increase in solubility of nimesulide at physiological pH due to the syn-ergetic effect of pH alteration and cyclodextrin complexation.

Preferred embodiments of the invention are inclusion complexes wherein the cyclodextrins and cyclodextrin derivatives are a, B and gamma cyclodextrins, and alkyl or hydroxyalkyl derivatives of cyclodextrin, preferably methyl B-cyclodextrins or hydroxy-propyl-B-cyclodextrin .

Further products of preference are inclusion complexes wherein the metal ion in the nimesulide salt is sodium of potassium. Alkaline earth salts e.g. the calcium or magnesium salts might also be used.

A further embodiment of the invention is the process for the preparation of inclusion complexes of nimesulide alkali and alkaline earth salts and cyclodextrins or cyclodextrin derivatives reacting nimesulide alkali and alkaline earth salts in the presence of water with cyclodextrins or cyclodextrin derivatives at pH 7 to 9.5 preferably at pH 7.5 to 8.5.

When carrying out this process it is advantageous to use nime-sulide alkali or alkaline earth salts formed in situ in the reaction mixture by adjusting the suspension of nimesulide in water to a pH value of 7 to 9.5 preferably 7.5 to 8.5 by addition of alkali and alkaline earth hydroxides, alkali and alkaline earth carbonates, alkali and alkaline earth hydrogen carbonates, alkali and alkaline eai;th phosphates, preferably sodium hydroxide, disodium phosphate and/or sodium hydrogen carbonate. Buffers may be used to adjust the desired pH-values.

After formation of the complex water may be removed by freeze-drying, spray-drying, low temperature vacuum evaporation, vacuum drying or other known methods. Aqueous solutions of the complexes or solutions containing the complex formed in situ from the ingredients nimesulide salt and cyclodextrins or cyclodex-trin derivatives are also objects of the present invention.

The inclusion complexes according to the present invention were prepared with α, β and gamma-cyclodextrin or with highly soluble hydroxy alkylated and methylated B-cyclodextrin derivatives preferably with randomly methylated β-cyclodextrin, DIMEB or TRIMEB.

The inclusion complexes according to the invention can easily be redissolved in distilled water or physiological saline to obtain clear or slightly opalescent solutions at physiological pH values of 200-600 times higher dissolved nimesulide concentration than its aqueous solubility.

Further objects of the invention are new pharmaceutical compositions containing as active ingredient the highly soluble, physiologically acceptable inclusion complex of nimesulide alkali and alkaline earth salt and cyclodextrins or cyclodextrin derivatives as stated above.

Pharmaceutical compositions of particular importance are those containing as active ingredient the inclusion complex of nimesulide sodium salt and β cyclodextrin. The compositions may contain other pharmaceutically acceptable ingredients such as used for formulation by the pharmaceutical industry.

The complexes and compositions according to the present invention can be used in pharmaceutical formulations administered by oral, parenteral, rectal or topical route. The aqueous solutions of the complexes can also be used in sprays.

The complexes according to may be used -A- --f-u-r-the-r-- -e-mbodiment-of- the invention consists in methods of treating patients in need of antiinflammatory and/or analgetic treatment administering to the patient an effective amount of an inclusion complex of cyclodextrins or cyclodextrin derivatives formed with nimesulide alkali and alkaline earth salt.

Most probably the complex - after dissolution in the gastrointestinal tract - is subject to an equilibrium whereby mole- cularly dispersed nimesulide is formed in the gastric juices , accelerating and improving absorbance and action of the drug.

The invention is illustrated by the following Examples without restricting the scope to their contents.

Examples on chemical synthesis and solubility Example l .

Excess amounts of nimesulide were stirred at 30°C in 5 ml samples of distilled water, pH 7.6, 8.0 and 9.6 alkali phosphate buffer solutions containing 0.0, 0.5, 1 and 1.8% (w/v) of β- cyclodextrin. After 18 hours of equilibration the suspensions were filtered across a 0.45 μιη membrane filter. The dissolved nimesulide contents of the filtrates were analyzed by spectrophotometry after appropriate dilution with 0.05 N hydrochloric acid in 50% (v/v) ethanol . Absorbance max 300±3 nm was used for quantitative calculation.

Table 1. summarizes the obtained results, whereby final pH values of the filtered solutions are also indicated.

TABLE 1 BCD Dissolved Nimesulide Final pH of solutions g/ml % dist . pH 7.6 pH 8.0 pH 9.6 pH 7.6 pH 8.0 pH 9 water 0 0.010 0.034 0.07 0.28 7.40 7.70 8.30 0.5 0.024 0.170 0.26 0.80 - - - 1.0 0.035 0.330 0.42 1.27 7.30 7.46 8.09 1.8 0.054 0.570 0.85 1.79 7.24 7.45 7.92 Nimesulide-Na solutions alone and in the presence of equimolar BCD were titrated with 0.1N H3PO4. At different pH values the opalescence of the solution became stronger (drug precipitation). Samples are analysed for dissolved nimesulide content by UV spectrophotometry. Figure 2 shows the decrease of nimesulide solubility in the presence and absence of BCD as a function of pH. Dissolved nimesulide in g/ml is shown against pH values. At around pH 8 almost all nimesulide remains dissolved in presence of BCD while almost the whole drug precipitates from the control solution. (About 10 mg/ml dissolved nimesulide as compared with less than 1 mg/ml). pKa of nimesulide is shifted to lower value by CD- complexation .

Example 2. 95 g B-cyclodextrin (0.076 moles, water content 10%) are suspended in 1200 ml of distilled water with vigorous stirring and 12 g (0.038 moles) of nimesulide dissolved in 80 ml of 0.5 N aqueous sodium hydroxide solution are added. When obtaining a homogeneous solution the pH of the solution is adjusted with 0.5 M H3PO4 to pH 8.2-8.6 and the yellow solution is feeze-dried to isolate the solid complex. 98 g nimesulide sodium salt/BCD complex of 1:2 molar ratio (a bright yellow fine powder) are obtained. Nimesulide content: 11.8±0.1% measured by UV- spectrophotometry .

Solubility properties of the complex: 100 mg of the product can be dissolved in 3 ml of distilled water resulting in a yellow solution with approximately 4 mg/ml nimesulide content, the solution having a pH value of 7.6+0.1.

DSC curve of the complex is identical with that of the complex obtained according to Example 3 below. Disappearance of the en-dothermic peak at 240 - 241 "c points to the absence of free nimesulide in the inclusion complex of 1:1 nimesulide sodium-BCD (molar ratio) .

Example 3. 33.2 g of B-cyclodextrin (0.025 moles, water content 13.7%) are suspended in 550 ml of distilled water. 8.25 g of nimesulide (0.025 moles) are dissolved in 60 ml of a 0.5 N aqueous sodium hydroxide solution and added to the suspension of B-cyclodextrin under vigorous stirring resulting in a clear dark yellow solution. The pH of the solution is adjusted with 0.5 N H3PO4 to pH 8.5-8.7 and the solution is freeze-dried to obtain the solid complex. 41 g of ni esulide-sodium salt/BCD complex of 1:1 molar ratio are obtained as a yellow fine powder. Nimesulide content: 20.0+0.2% measured by UV-spectrophotometry .

Solubility properties: 100 mg of the complex can be dissolved in 6 ml of distilled water resulting in a slightly . opalescent solution with approximately 3.5 mg/ml nimesulide content, the solution having a pH value of 8.3±0.1.

Differential scanning calorimetry (DSC) curves show characteristic differences between the physical mixture and the lyophili-zed complex. The sharp endothermic heat flow peak characteristic for the melting of nimesulideVappears at 240 - 241 C on the DSC curve of the physical mixture, followed by a strong exothermic DSC peak characteristic for thermal decomposition of BCD . The DSC pattern of the inclusion coirplex does not show any endothermic heat flow in the melting range indicating the formation of an inclusion complex between the salt and β-cyclodextrin, only a strong exothermic DSC peak characteristic for thermal decomposition of BCD can be observed.

Figure 3 shows the DSC curves of the nimesulide-sodium : BCD = 1:2 physical mixture (A) and the nimesulide-sodium/BCD complex (B) prepared according to Example 3 : Heat flow (mW) is represented as a function of temperature (°C) [Du Pont 1090 Thermal Analyzer, scanning rate 5°C/min, argone atmosphere].

The nimesulide-potassium salt/BCD complex is prepared according to the same method, using KOH instead of NaOH.

Similarly the nimesulide-calcium and magnesium salt/CD complexes can also be prepared.

Example . 30.2 g of B-cyclodextrin (0.024 moles, water content 10%) and 3.75 g of nimesulide (0.012 moles) are suspended in 25 ml of a 0.5 N aqueous sodium hydroxide solution. The thin suspension is stirred by Ultra Turrax high speed dispersing apparatus with r.p.m. approx. 103 for five minutes. The pH of the alkaline non-transparent solution is adjusted below pH 9. with l N aqueous hydrochloric acid. The solid complex is isolated by dry- ing at 40 °C under vacuo, and the dry complex in powdered. 34 g of nimesulide-sodiu salt-BCD comlex (1:2) are obtained as a yellow fine powder. Nimesulide content: 11±0.1% measured by UV-spectrophotometry .

Solubility : 100 g of the complex dissolved in 3 ml of distilled water resulted in an opalescent solution with approximately 3 mg/ml dissolved nimesulide content, the solution showing a pH value of 7.3±0.1.

Example 5. 40 g of randomly methylated B-cyclodextrin (RAMEB 0.034 moles, average degree of substitution per glucose unit is 1.8) are dissolved in 300 ml of distilled water. 5.4g of nimesulide (0.017 moles) dissolved in 17 ml of 1 N aqueous sodium hydroxide are added whereupon the pH of the solution is adjusted with 0,5 N H3PO4 to pH 7.7±0.l. The yellow solution is freeze-dried to isolate the solid complex. 45 g of nimesulide-sodium salt-randomly methylated-B- cyclodex-trin (RAMEB) complex of 1:2 molar ratio are obtained in the form of a fine yellow powder. Nimesulide content: ll.l±0.1% measured by UV-photometry .

Solubility: 100 mg of the complex dissolved in 2 ml of distilled water result in a yellow solution (pH 7.310.1) with approximately 6 mg/ml nimesulide content.

Example 6. 2.6 g of gamma-CD (0.002 moles) are dissolved in 20 ml of distilled water and 0.308 g (0.001 moles) of nimesulide dissolved in 5 ml of 0.2 N aqueous sodium hydroxide are added whereupon the pH of the solution is adjusted to pH 7.4-7.5, and the yellow solution is freeze-dried. 2.9 g of nimesulide sodium salt/gamma-CD complex of 1:2 molar ratio are isolated in the form of a very fine yellow powder. Nimesulide content: 10.5 ± 0.2% measured by UV-photometry. 100 mg in 2 ml of distilled water give a clear yellow solution with approximately 5 mg/ml nimesulide content ( pH= 7.3 ± 0.1 ) .

Example 7. 13 g of hydroxypropylated BCD (0.01 mole average degree of sub-stitutaion per glucose unit is 2.7) are dissolved in 150 ml of distilled water and 1.54 g of nimesulide (0.005 M) and 5 ml of IN sodium hydroxide are added while stirring. A dark clear yellow solution is obtained the pH of which is adjusted to 7.5 ± 0.1 with 0.2 N phosphoric acid, and the solution is freeze-dried. 14 g of nimesulide sodium/HPBCD complex of 1:2 molar ratio are obtained in the form of a very fine yellow powder.

Nimesulide content: 10.6 ± 0.2% measured by UV photometry. 100 mg of this complex dissolved in 2 ml of distilled water resulting in a clear yellow solution with about 5 g/ml dissolved nimsulide content (pH of the solution = 7.4 ± 0.1).

Example 8.

The dissolution of nimesulide-Na/BCD complex prepared according to Example 2 was compared to nimesulide-Na and nimesulide-Na/BCD complex prepared in situ from the corresponding 1:2 molar physical mixture of the components. Simulated gastric juice was used as a medium. 100 mg of nimesulide, an equivalent amount of the isolated complex and the physical mixture of the ingredients were stirred in 20 ml of pH 1.4 aqueous HC1 solution. Samples were taken at 2, 15 and 60 minutes. On filtration the nimesulide content was measured by UV photometry. Average results of three experiments are summarized in Table 2.

Table 2.

Concentration of Dissolved Nimesulide (μg/ml) time (min) Nim.-Na Nim. -Na/BCD Nim. -Na/BCD isolated complex in situ complex 2 5.4 ± 0.7 35.4 ± 1.4 33.3 ± 2.2 15 4.0 ± 0.1 36.1 ± 0.25 33.3 ± 0.3 60 4.4 ± 0.5 34.6 ± 1.5 35.1 + 0.2 The measurable nimesulide concentration both for the isolated complex and the in situ formed complex are approximately five times higher than in the case of nimesulide-Na substance. This higher concentration is maintained even after 60 minutes. The results indicate that in situ complex formation from the physical mixture took place under the conditions employed.

Example 9.

A comparative solubility test was carried out using nimesulide- Na/BCD complex tablets (100 mg) , Mesulid commercial tablets (batch N° 891 1026/SCAD 91/11. 100 mg) and nimesulide-Na salt substance (prepared by lyophilization from a solution of 1:1 molar ratio ni esulide and sodium hydroxide, using an equivalent amount to 100 mg of nimsulide) .

Powdered tablets of each sample were suspended in 20 ml of pH 1.4 aqueous HCl solutions and stirred at ambient temperature. Samples were taken after 2, 60 and 90 minutes. On filtration the nimesulide concentration of the filtrates was evaluated by UV- spectrophotometry after dilution with 96% ethanol. Absorbance atj^max ~ 299 ± 1 nm was used for quantitative calculation taking Eicm 299 ± 1 nm = 257 for nimesulide. Results are summarized in Table 3.

Table 3.

Nimesulide concentrations as a function of time at pH = 1.4 Nimesulide cone, (μg/ l) 2 in. 60 min. 90 min.

Nim. -Na/BCD tbl . 35 43 37 Mesulid tbl. 10 14 11 Nim.-Na salt 7 10 6 Table 3. shows that considerable solubility differences are found in favour of the complex tablets. It is obvious that the solubility of an acid type drug might be lower in a pH 1.4 solution than in water. The alkali salts of the drug are freely soluble in water. Their in vivo absorption however after oral administration is delayed owing to the precipitation of the acid-form under the pH of the stomach.

BCD complexation enhances solubility of nimesulide also under acidic pH conditions. Based on the above in vitro findings an improved absorption of nimesulide-salt complexes is understood after oral administration because the solubility under acidic pH is a necessary precondition e.g. for faster onset of action.

Example 10. 2.3 g of BCD (0.002 moles, water content 14%) and 0.31 g of nimesulide (0.001 mole) are suspended in 100 ml of distilled water. 2 ml of 0.5N aqueous potassium hydroxide are added while stirring. pH of the dark yellow solution obtained is adjusted below 9 using 0.5N hydrochloric acid. 2.8g of nimesulide-K/BCD complex (1:2) are isolated by freeze-drying. Nimesulide content: 10.8 ± 0.2% (UV spectr.) Solubility: 100 mg of the above complex are dissolved in 3 ml of distilled water. A clear or slightly opalescent solution with « 3mg/ml dissolved nimesulide results, pH 7.8 ± 0.1.

Examples on Pharmaceutical Compositions.

Example 11.

Composition of tablets with 50 mg and 100 mg of nimesulide content: nimesulide-sodium salt/fiCD complex ( Example 3) 250 mg 500 mg calcium phosphate 60 mg 85 mg lactose 35 mg 45 mg magnesium-stearate 5 mg 5 mg Total 350 mg 540 mg The complex is homogenized with the additives and directly pressed into tablets.

Example 12.

Composition of granule sachet formulation with 50 mg and 100 mg of nimesulide content of each. nimesulide-sodium salt/BCD 450 mg 900 mg sorbite 2500 mg 4000 mg lemon flavour 15 mg 30 mg saccharine 5 mg 5 mg Total 2970 mg 4935 mg The complex is homogenized with sorbite and additives and filled into sachets.

Example 13.

Composition of oral liquid formulation with 50 mg/10 ml nimesulide content nimesulide-K/BCD complex (Ex 3.) 2.500 g hydroxypropyl cellulose 0.200 g potassium sorbate 0.150 g fructose 5.0 g saccharine sodium qu.sat. demineralized water ad 100.0 ml The viscosity enhancer is dissolved in about 80 ml of warm demineralized water and the complex added and dissolved. Other addi- P~9416 tives are added to obtain a homogeneous solution. Each spoon (~10 ml) contains 50 mg of nimesulide.

Example 14.

Composition of ointment with 10 mg/1 g nimesulide content: Complex of Example 5 9 g hydrophilic ointment 91 g Tota.1 100 g The hydrophilic ointment base is melted at 50-60 °C and the nime-sulide-salt complex is added under stirring to obtain a homogeneously dispersed system. Under continuous stirring the ointment is cooled to room temperature and put into containers of 100 g. Example 15.

Composition of a parenteral formulation containing 5 mg/ml of nimesulide sodium salt-gamma-CD complex: Complex of Example 6 500 mg sodium chloride 81 mg distilled water for injections ad 10 ml Proper volumes of the complex solution are filled into containers with 50 mg nimesulide content each and lyophilized. Before use the lyophilized powder is dissolved with distilled water. Example 16.

Composition of suppository containing 50 mg of nimesulide: Complex of Example 3 250 mg polyethylene glycol-suppository base 1250 mg Total 1500 mg The complex is homogenized with the melted suppository base and formulated to give suppositories.

Example 17.

Hard gelatine capsules used for in situ complexes: nimesulide-Na 53.5 mg 107 mg BCD 214 mg 428 mg Mg stearate 2.5 mg 5 mg Total 270 mg 540 mg The complex is formed when dissolving the capsule in acidic medium or after administration in the gastrointestinal tract. 111723/2

Claims (9)

1. Highly soluble inclusion complexes of nimesulide alkali and alkaline earth salts of general formula (I) A N - S02Me N02 where - A stands for an alkali and alkaline earth ion - with cyclodextrins and cyclodextrin derivatives. 111723/2 - 15 -

2. Inclusion complex of nimesulide sodium, potassium, magnesium or calcium salt with β-cyclodextrin or gamma cyclodextrin the molar ratio of the salt to cyclodextrin being 1:1 or 1:2.

3. Inclusion complex according to claim 1 wherein the cyclodextrins and cyclodextrin derivatives are , β and gamma cyclodextrins, and/or alkyl or hydroxyalkyl derivatives of cyclodextrin, preferably methyl β-cyclodextrins or hydroxypropyl-β- cyclodextrin.

4. Inclusion complex according to claim 1 wherein the nimesulide alkali is nimesulide sodium salt.

5. Process for the preparation of inclusion complexes of nimesulide alkali and alkaline earth salts and cyclodextrins or cyclodextrin derivatives c h a r a c t e r i z e d b y reacting nimesulide alkali and alkaline earth salts in the presence of water with cyclodextrins or cyclodextrin derivatives at pH 7 to 9.5, preferably at pH 7.5 to 8.5.

6. Process according to claim 5 c h a r a c t e r i z e d by using nimesulide alkali and alkaline earth salts formed in situ in the reaction mixture by adjusting the suspension of nimesulide in water to a pH value of 7 to 9.5 preferably 7.5 to 8.5, by addition of alkali and alkaline earth hydroxides, alkali and alkaline earth carbonates, - hydrogen carbonates, - phosphates, preferably sodium hydroxide, disodiu phosphate and/or sodium hydrogen carbonate or other buffers. 111723/4 .-·- 16 -

7. Process according to any of claims 5 and 6 chractarlzed by removing water after formation of the complex by freeze-drying, spray-drying, low temperature vacuum evaporation, vacuum drying or other method known per as.

8. A pharmaceutical composition containing a highly soluble , physiologically ^ acceptable inclusion complex comprising nimesulide alkali or alkaline earth salts and cyclodextrine or cyclodextrin derivatives, according to claim 1 as active ingredient.

9. A pharmaceutical composition according to claim 8 ^ characterized by its containing as active ingredient the inclusion complex of nimesulide sodium salt and β cyclodextrin possibly along with other pharmaceutically acceptable ingredients. FOR THE APPLICANT Dr. Yitzhak Hess & Partners