FI95349C - Process for the preparation of a gelatin capsule containing 7 - [(Z) -2- (2-aminothiazol-4-yl) -4-carboxybut-2-enoylamino] -3-cephem-4-carboxylic acid - Google Patents

Description

1 95349

The present invention relates to a process for the preparation of a gelatin capsule comprising: 7β-Γ (Ζ) -2- (2-aminothiazol-4-yl) -4-carboxybut-2-enowliaminol-3-cephem-4-carboxylic acid. contains the antibacterial drug 7β - [(Z) -2- (2-aminothiazol-4-yl) -4-carboxybut-2-enoylamino] -3-cephem-4-carboxylic acid (hereinafter referred to as 7432-S).

10

The capsule to be prepared is a strong, hard gelatin capsule containing a pharmacologically effective amount of 7432-S hydrate and sealed with a gelatin strip around the junction of the capsule lid and the body.

The starting compound 7432-S, which is useful due to its wide spectrum and high efficacy against Gram-positive and negative bacteria, is described in Japanese Patent Application (Kokai) 60-78,987.

20

The gelatin-sealed capsule structure is described in Japanese Utility Model 45-20800, which describes how to fill and seal a liquid in a capsule.

25

It has been found that the starting compound 7432-S is unstable even in crystalline form and loses its potency or changes color after standing for a longer time. After numerous experiments, the reason was that the compound was prepared by drying under reduced pressure with phosphorus pentoxide in a conventional manner, leaving an anhydrous substance known to remain.

. Additional studies using some standard stabilization methods (e.g., addition of a stabilizer, dry granulation of water-unstable antibacterial agents, film coating of granules) did not give a satisfactory result of antibacterial stabilization. For clinical use of this compound, a more stable form was required.

2 95349

According to the invention 1) Crystalline 7432-S hydrate has a constant X-ray diffraction pattern and high chemical stability.

5 2) The hydrate can be protected from discoloration and loss of potency if it is placed in a hard gelatin capsule closed with a gelatin belt around the junction of the capsule lid and body. The method was known using capsules containing liquids but not solid powders as in the present invention.

I Hydrate

According to the present invention, an attempt has been made to find a method for improving the stability of 7432-S, and it has been found that the crystalline hydrate prepared under special conditions has almost the same X-ray diffraction pattern and high chemical stability, so that longer storage is possible. This finding is the basis of the present invention. This crystalline hydrate is a crystalline powder with a slight yellowish-white to pale yellowish-white color.

Elemental analysis of the crystals shows that the hydrate contains 25 to 2 moles of water of crystallization and also up to one mole of water depending on the conditions, e.g. during crystallization and drying.

The water content was determined by the Karl Fischer method and ranged from 7-14%, (especially 8.7-12.5%), corresponding to (di -> tri) hydrate or a mixture thereof.

»

The thermogram of the atmospheric end shows that the first and second water molecules remain up to about 140 ° C but 35 that the third water molecule disappears at 30-60 ° C.

The above explains why the third water molecule is weakly bound to the crystalline structure and is easily lost (e.g., by heat, low humidity, or vacuum 3,953,449).

Each crystalline hydrate in this water content range (i.e., in the range from dihydrate to trihydrate) has nearly the same X-ray diffraction pattern as shown in Table 1.

Table 1 The X-ray diffraction pattern was observed under the following conditions: X-ray wavelength = 1.5418 Å (copper Ka: Ni filter) 40 kV-20 mA. The lattice interval d is expressed in Ä. The relative intensity in I / I0 indicates the percentage intensity in 20.95 Å.

15 d I / I0 d I / I0 d I / I0 d I / I0 5.90 12 20.95 100 28.70 17 35.93 8 7.35 8 21.15 70 29.40 27 36.38 24 9 , 45 92 21.75 25 29.60 11 37.00 7 10.15 21 22.25 49 29.90 16 38.30 26 20 12.08 46 23.85 62 30.40 19 38.65 10 14, 87 30 24.50 39 31.10 53 39.20 15 15.65 14 24.80 16 31.60 23 39.60 21 ··: 16.25 13 25.50 34 31.78 34 40.27 15 18 , 35 24 25.85 66 33.02 28 41.22 22 25 18.90 71 26.60 16 33.55 23 42.55 8 19.14 77 27.02 59 33.86 17 44.20 9. 19.40 60 27.30 35 35.20 16 20.58 88 28.35 54 35.65 10 30

According to the present invention, the crystalline hydrate contains 96-100% (especially 99.0-99.8%) of the cis-geometric isomer • (i.e., the (Z) -metric isomer) having a 7-side chain double bond, regardless of the ratio of the starting material. .

According to the present invention, the crystalline hydrate has a strong absorption range in the 1700 cm-1 iR absorption spectrum observed on a potassium bromide plate. This area is not found in the case of water-free crystals.

The preparation of the crystalline hydrate is described below.

10 (1) General course

The crystalline hydrate can be prepared by the following method: the starting material 7432-S is dissolved in aqueous acid and the pH of the solution is raised (especially to pH 1.5-5.0) at about room temperature (especially 0-70 ° C) to separate the crystals. If necessary, stir the mixture to complete the crystallization. The wet crystals are separated and dried at about room temperature and at about atmospheric pressure in an inert gas having a relative humidity of not less than 15%.

(2) Starting material The starting material may be wet or anhydrous. It may be a free compound or a salt having an amino (e.g. an acid addition salt) or a carboxy (e.g. an alkali metal salt). The process according to the present invention together with the pretreatment (e.g. purification, isomerization to the cis isomer, isolation) using a water-soluble salt (e.g. alkali metal salt, hydrochloride) as a starting material to obtain an aqueous acid solution is a formulation used in this invention.

. !. (3) Acid 35 An aqueous acid solution 7432-S can be prepared by slurrying the free acid or ammonium salt or by dissolving the carboxylate salt as a starting material in water and then adding acid. Said acid may be an inorganic acid (e.g. hydrochloric acid, sulfuric acid, phosphoric acid), carboxylic acid (e.g. acetic acid, malic acid, fumaric acid, citric acid), sulfonic acid (e.g. methanesulfonic acid, sulfonic acid, ethanesulfonic acid) , an acidic salt (e.g. dimethylamine hydrochloride, 7432-S-sulfate) or a similar hydrophilic acid which can acidify an aqueous solution of the starting material. In particular, molar equivalents of about 0-20 (especially 1-10) acids can be used.

(4) Interactive solvents

The aqueous solution may contain 0-70% of a water-miscible organic solvent, e.g. an alcohol (e.g. methanol, ethanol, isopropanol, t-butanol, methoxyethanol), an amide (e.g. dimethylformamide), a nitrile (e.g. aceto-15 ninitrile). ), sulfoxide (e.g. dimethyl sulfoxide), ether (e.g. dioxane, tetrahydrofuran, dimethoxyethane), ketone (e.g. acetone, methyl ethyl ketone) or the like as co-active solvents.

20 (5) Concentration The concentration of the starting material in the aqueous acid solution can mainly occur in the range of 2.0-15.0% (especially 3.0-5.0%).

25 (6) Neutralization

A base (solid or liquid) that can neutralize the aqueous acid solution to a predetermined pH can be used to adjust the aqueous acid solution at room temperature (about 0-70 ° C, especially 10-50 ° C) to approximately isoelectric. to a point (pH about 1.5-5.0, especially 2.0-3.5). Alternatively, the acid solution may be diluted with water to increase the pH sufficiently to separate the hydrate. Suitable bases include organic bases (e.g. triethyl-35 amine) and inorganic bases (e.g. ammonium hydroxide, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate), of which water solubility is not limited, although not limited. Water-insoluble 6,953,449 bases (e.g., anion exchange resins) can also be used for this purpose.

(7) Crystallization 5

For isolation and maturation of the crystals, stirring of the suspension of crystals to be isolated is continued for mainly 10 minutes to 50 hours at 0-70 ° C (especially 5-35 ° C).

io (8) Drying

Drying is carried out mainly under mild drying conditions (e.g. local drying, flow-through drying, circulating drying or fluidized bed drying) with an inert gas (e.g. air, nitrogen, carbon dioxide) at relative humidity (not less than 15%) at approximately room temperature (e.g. 0-60 ° C). depending on the agitation and powder flow conditions.

20 The following observations have been made on a laboratory scale: eg in the case where drying takes place in a closed vessel at atmospheric pressure, the water content reaches the first elevated value, which corresponds to the dihydrate in air with a relative humidity of 15-50% (especially 20-30%) At 25-60 ° C for 1-8 25 hours, and a second Elevation value corresponding to the trihydrate in air with a relative humidity of 45% or; ·· more (especially 50-80%) at 25-60 ° C (especially 10-25 ° C) for 1-8 hours.

already In the case of flow-through or circular drying, a product corresponding to the dihydrate as the main ingredient is obtained. This depends on the agitation and powder flow conditions, e.g. heat flow drying in air with a relative humidity of 15-60% at 25-40 ° C up to 35 ° C versus exhaust air heat curve or time versus exhaust air humidity curve (approx. 2- 10 hours when the starting material contains 30-60% water).

• In the case of fluidized bed drying, 7 95349 are obtained - depending on the air flow conditions, eg drying in air with a relative humidity of 50-60% at 10-35 ° C (especially 20-32 ° C) until the first inflection point versus exhaust air temperature is reached or time counter-5 humidity curve of the exhaust air (approx. 1 hour when the starting material contains 30-60% water) - product corresponding to the trihydrate and correspondingly until the second inflection point of the same curves is reached (approx. 1.5 hours when the starting material contains 30-60% water), a product corresponding to the dihydrate as the main constituent. In larger production, circular drying, flow-through drying and fluidized bed drying are preferably used.

In the typical case of fluidized bed drying, depending on the air flow rate per unit weight, wet crystals, or other conditions, are obtained by air drying with a relative humidity of 20-80% (especially 50-60%) at 10-60 ° C (especially 20-30 ° C). ) up to the first inflection point versus exhaust air temperature or time versus exhaust air humidity curve (approx. 1-5 hours when starting material 20 contains 30-60% water) - crystalline trihydrate and corresponds to the second inflection point (approx. 3-7 hours when starting material contains 30-60% water) crystalline dihydrate as the main ingredient.

Drying at a temperature higher than about 60 ° C in the presence of a desiccant, under reduced pressure or other similar difficult conditions, reduces the water of crystallization to less than 2, makes the product unstable (e.g. drying less than 0.01 mmHg of calcium chloride at 25-28 ° C reduces water content to 1.5-4.8% in three hours, drying in circulating 30 dry nitrogen at 25 ° C reduces the water content to 1.08% in 30 minutes).

The stability of the crystalline hydrate of the present invention was confirmed by an acceleration test showing 97.8% of the maintenance of potency after 35 months compared to the value of the anhydrous substance (73.6%).

A pharmacologically effective amount of the crystalline hydrate of the present invention can be used in oral formulation 95349 8 (especially capsules, granules, tablets) for the prevention or treatment of bacterial infections. Alternatively, the crystalline hydrate may be stored for further processing.

5 II Sealed capsules

According to the present invention, an attempt has been made to find a structure capable of keeping 7432-S hydrates stable for a longer period of time without unnecessarily high costs, and it has been found that hydrates placed in gelatin hard gelatin capsules have significantly less discoloration and power loss.

Capsules of the present invention can be prepared by mixing a pharmacologically effective amount of hydrates and an additive (e.g., a size enhancer, a lubricant), then filling it into a capsule, attaching an aqueous gelatin solution around the capsule body and body junction, and drying to form a gelatin belt.

The hard gelatin capsule may be a conventional, commercial capsule without specific size and color restrictions. It may contain a dye and / or a pigment.

25

Although an additive (e.g., a size enhancer or lubricant) is not necessary to protect the hydrate from discoloration or loss of performance, additives are used primarily to make it more convenient to fill a pharmacologically effective amount of hydrate into the Cap-30 capsules. Size enhancers may be those commonly used in powders or granules, e.g. sugar (e.g. glucose, fructose, lactose), starch (e.g. corn starch, potato starch) or cellulose (e.g. crystalline cellulose, methylcellulose, methylethylcellulose). Lubricants may be those commonly used in powders, granules or tablets, e.g. purified talc, stearic acid or a salt thereof (e.g. sodium, magnesium or calcium salt), borax, liquid paraffin, sodium benzoate, polyethylene glycol (average molecular weight) 6000349349 or hydrogenated oil.

An aqueous gelatin solution can be prepared by dissolving 10-30% (preferably 15-25%) of gelatin in water, optionally 1-40% lower alkanol (e.g. 20-30% methanol, ethanol, propanol or glycerol), ethers (e.g. 0.5-10% polyoxyethylene sorbitan monooleate = polysorbate), ketone or esters in a conventional manner so that the solution can be attached to the capsule junction and dried (e.g.

10 with air flow or heat) at 0-80 ° C. Typically, 5 to 50 mg of a gelatin solution, optionally containing a pharmaceutically acceptable pigment, is attached to a size 2-4 gelatin capsule.

The following examples and experiments illustrate the present invention.

However, they should not be construed as limiting the scope of the present invention. The water content was determined by the Karl Fischer method.

20 I Hydrate

Example 1

A crude solution of 7432-S (25 g) in 6N hydrochloric acid (75 ml) was allowed to stand for 1 hour at 15-20 ° C to separate the hydrochloride. The crystals were collected by filtration, washed with acetonitrile (75 ml) containing 1 drop of concentrated hydrochloric acid and dried to give crystalline 7432-S-hydrochloride monohydrate (18 g).

This solution of monohydrate (1.0 g) in 3N hydrocarbon acid (4 ml) was adjusted to pH 1.5 by the addition of water (30 ml) and i base and stirred for 2.5 hours at 25-45 ° C. The crystals to be separated were collected by filtration and washed with water. The crystals were freeze-dried for 5 hours at 10 ° C to give crystalline 7432-S hydrate (°> 7 g) having a water content of 10.2%. Geometric isomer ratio (cis / trans) = 98.8: 0.2.

il III 1 Silli I i l ITI

10 95349

Example 2

The crude crystalline 7432-S (1.17 g) was slurried in a mixture of t-butanol (3 ml) and acetonitrile (3 ml). To this suspension was added 35% hydrochloric acid (1 mL; 5 molar equivalents) to give a solution. This solution was diluted by stirring t-butanol (3 mL), acetonitrile (9 mL) and water (5 mL), adjusted to pH 2.3 with triethylamine and stirred for 3 hours at 30-35 ° C. The separable crystals were collected, washed with a mixture of acetonitrile, t-butanol and water (2: 1: 1; 5 ml) and water (10 ml) and dried by flow-drying for 2 hours at 25-30 ° C to give crystalline hydrate (1.06 g) with a water content of 8.75%. The geometric isomer ratio was (cis / trans) 99.2: 0.8.

Example 3

To a crude crystalline suspension of 7432-S (1.0 g) in a mixture of water (8 ml) and acetonitrile (1 ml) was added sodium hydrogen carbonate (0.41 g; 2 molar equivalents) to give a clear solution. This solution was diluted with methanol (6 mL), treated with activated carbon (0.1 g), stirred at room temperature for 10 minutes and filtered to remove activated carbon. The filtrate was acidified with 6N hydrochloric acid (1.62 ml; 4.5 molar equivalents) and poured into a mixture of water (3.4 ml) and acetonitrile (5 ml). The mixture was adjusted to pH 2.3 with 30% potassium carbonate, stirred for 1 hour at 40 ° C and for 1.5 hours at 20-25 ° C.

30

The crystals to be separated were collected, washed with a mixture of methanol, acetonitrile and water (1: 1: 2; 5 ml), water (20 ml) and methanol (5 ml) alternately and dried by flow-through drying at 20-25 ° C 1. For 5 hours to give a crystalline hydrate (0.876 g) with a water content of 9.35%. The geometric isomer ratio (cis / trans) was 99.6: 0.4.

Example 4

X1 9534P

To a solution of sodium bicarbonate (1.848 g; 3 molar equivalents) in water (42 mL) was added crude crystalline 7432-S (4.66 g).

The solution was treated with acetonitrile (19 mL), activated alumina (2.34 g) and activated carbon (0.466 g), stirred at 15-20 ° C for 30 minutes and filtered to remove activated carbon and alumina. The filtrate was poured into a mixture of acetonitrile (37 ml), 62% sulfuric acid (3.95 g) and water (28 ml). The mixture was diluted with aqueous 30% potassium carbonate (to pH 3.0) at 20-25 ° C and stirred for 30 minutes at the same temperature. The separable crystals were collected by filtration and dried by rotary drying at 20-25 ° C for 2-3 hours to give a crystalline hydrate (4.384 g) with a water content of 12.2%. The geometric isomer ratio (cis / trans) was 99.6: 0.4

Under similar conditions, a solution of 7432-S in 20 (1/0 g) aqueous sodium hydrogen carbonate (12 ml) was treated with active alumina and activated carbon. The solution was diluted and acidified with solvent (water, isopropanol or acetonitrile; (6 ml) and 85% phosphoric acid (8 molar equivalents) alternately, then the pH was adjusted to 3.0 with aqueous 30% potassium carbonate at 20-25 ° C. and stirred at the same temperature for 30 min.

The separable crystals were collected by filtration and dried by flow-through drying at 20-25 ° C for 2-3 hours to give a crystalline hydrate (ca. 0.90 g) with a water content of 11.0%. The ratio of geometric isomers (cis / trans) was 99.2 -> 99.7 / 0.8 -> 0.3.

Under the same conditions but replacing phosphoric acid with methanesulfonic acid (4 molar equivalents), a crystalline hydrate (0.879 g) was formed. Water content: 11.4%. Geometric isomer ratio tcis / trans) = 99.6 / 0.4.

12 95349

Example 5

To a crude crystalline suspension of 7432-S (2 g) in a mixture of dimethoxyethane (18 ml) and ethanol (2.0 ml) was added 6N hydrochloric acid (0.89 ml; 1.3 molar equivalents) at 2-5 ° C and the mixture was stirred at the same temperature for 2 hours. The separable hydrochloride crystals were collected by filtration, washed with a mixture of dimethoxyethane and ethanol (9: 1) and acetonitrile (10 ml) and dried at 25-30 ° C to give the hydrochloride (1.878 g).

This hydrochloride suspension (1.0 g) in a mixture of methanol (6 ml) and water (5 ml) was dissolved by the addition of sodium hydrogen carbonate (0.61 g; 3 molar equivalents) to give a solution.

To this solution was added activated carbon (0.1 g), the whole mixture was stirred at 25-30 ° C for 10 minutes and filtered to remove activated carbon. The filtrate was poured into a mixture of 35% hydrochloric acid (1.01 ml; 4 molar equivalents), water (3 ml) and acetonitrile (6 ml), the pH was adjusted to 20 with 3.0 with 30% aqueous potassium carbonate and the whole was stirred at 25-30 °. At C for 30 minutes and at 5-7 ° C for 1 hour. The separable crystals were collected by filtration, washed with ethanol (5 ml) and water (10 ml) alternately and dried by flow-drying at 20-25 ° C for 25 hours to give a crystalline hydrate (0.82 g) having a water content of 10 ml. 6%. The geometric isomer ratio (cis / trans) was 99.5: 0.5.

Example 6 30

To a solution of sodium hydrogen carbonate (1.3 g; 2.2 molar equivalents in water (18 ml) was added crude crystalline 7432-S (3.0 g).

. The solution was treated with activated alumina (1.5 g) and activated carbon (0.3 g), stirred at 20-25 ° C for 35 minutes and filtered to remove activated carbon and alumina. The filtrate was poured into a mixture of malic acid (10 molar equivalents), (17 ml) and acetonitrile (36 ml). The mixture was neutralized with aqueous 30% potassium carbonate. At 20-25 ° C to give a pH of 3.0 and stirred at 95349 for 30 minutes at the same temperature. The separable crystals were collected by filtration and rotary dried at 20-30 ° C for 2 hours to give a crystalline hydrate (2.665 g) having a water content of 11.7%.

The geometric isomer ratio (cis / trans) was 99.1: 0.9.

Under the same conditions but replacing malic acid with fumaric acid (10 molar equivalents), a crystalline hydrate with a water content of 10.1% was formed.

10

Similarly, a solution of 7432-S (1.0 g) in aqueous sodium hydrogencarbonate was treated with active alumina and activated carbon. The solution was stirred in a solution of formic acid (4 molar equivalents) in aqueous aceto-isinitrile. The mixture was treated as above to give a crystalline hydrate (0.925 g) with a water content of 12.7%. The geometric isomer ratio (cis / trans) was 99.8: 0.2. Said amount of formic acid can be added to 75 molar equivalents to give the same crystalline hydrate.

Example 7 A sample of 7432-S hydrate (1 g) prepared according to the method described in Example 25 3 was placed in a sealed container having a relative humidity of 0%, 12%, 20%, 44%, 57% or 75% (obtained by selecting an appropriate wet-drying means), and kept at room temperature for 6 hours. The water content of each of the 30 samples was then determined by the Karl-Fischer method, resulting in values of 1.05%, 5.83%, 8.54%, 11.21%, 12.19% or 12.21%.

: The values indicate that the main components are the dihydrate (estimated water content 8.07%) at a relative humidity of 20% 35 and the trihydrate at a relative humidity above 44%. When this drying was continued for another 30 hours, the water content decreased by less than 0.2% over 6-30 hours in the case where the relative humidity was more than 20%.

; l «H l mill LU.a. : i

Example 8 A sample of 95349 14 7432-S (1 g) prepared according to the method described in Example 3 was placed in a hermetically sealed container with a relative humidity of 20%, 44%, 57% or 75% (obtained by selecting an appropriate wet drying method). and maintained at 40 ° C for one month. The water content of each sample was then determined by the Karl Fischer method, resulting in values of 7.92%, 10.69%, 11.73% or 12.4%. The water content decreased by less than 0.5% over a period of 30 hours to one month, indicating a stable water content.

II Sealed capsules 15

In the following Examples 9-14 and Comparative Examples 1-6, 7432-S hydrate is in crystalline form and contains about 10% water of crystallization when determined according to the Karl-Fischer method.

20

Example 9

Hydrate (1 kg), crystalline cellulose (1.18 kg) and magnesium stearate (0.02 kg) (each powder 60 mesh) were mixed for 20 minutes using a 10 liter V-type mixer. The mixed powder (253 mg each) was filled into white hard gelatin hard capsules number 2 containing titanium dioxide (3.5%). A closure gelatin solution [(21.13%) and polysorbate 80 (2%)] was then fixed around the top of the capsule and the body junction (S-100 hard cap-30 closure machine dispensed by Japan Elanco was used).

Company) and dried in a stream of air for 5 minutes. the product contains 100 mg of effective 7432-S per capsule.

Example 10 35 Hydrate (1 kg), lactose (1.9 kg) and hydrogenated castor oil (0.1 kg) (each powder such as 60 mesh) were mixed for 20 minutes using a 10 liter V-type mixer. The mixed powder (172 mg each) was filled into white. to gelatin capsules No. 2 containing titanium oxide 15 95349 (6%). A closure gelatin solution [20-25 mg at 55 ° C was then attached; water-soluble gelatin solution (22%), glycerol (5%) and ethanol (30%)] around the capsule lid and body junction (using a S-100 hard capsule sealer dispensed by Japan Elanco Company) and air dried at room temperature for 5 minutes. the product contains 50 mg of the effective 7432-S substance per capsule.

Example li 10 Hydrate (1 kg), crystalline cellulose (0.5 kg) and powdered carnauba wax (0.02 kg) (each as powder 60 mesh); was stirred using a 10 liter C-type stirrer for 20 minutes. The mixed powder (171 kg each) was filled into No. 4 white gelatin hard capsules containing titanium dioxide (2.1%). The barrier gelatin solution was then fixed [10-20 mg at 60 ° C; an aqueous solution of gelatin (22%) and polysorbate 80 (2%)] around the capsule lid and body junction (using a S-100 hard capsule sealer dispensed by the Japan Elanco Company) and dried in a stream of 20 air at room temperature for 4 minutes. The product contained 100 g of effective 7432-S per capsule.

Example 12

The capsule was prepared according to Method 25 of Example 9 except that a transparent No. 4 gelatin hard capsule was used.

Example 13

The capsule was prepared according to the method 30 shown in Example 9 except that an opaque blue 9 gelatin hard capsule No. 4 containing groove blue color No. 1, red color No. 3 and titanium dioxide was used.

Example 14 A capsule was prepared by the method described in Example 9 except that an opaque red gelatin capsule No. 4 containing career blue color No. 1, red color No. 3, yellow color No. 5 and titanium dioxide was used.

95349 BC

Comparative Example 2 (to Example 10)

Hydrate (1 kg), crystalline cellulose (1.18 kg) and magnesium stearate (0.02 kg) (each as a 60 mesh powder) were mixed for 20 minutes in a 10 liter V-type mixer.

The mixed powders (253 mg each) were filled into No. 2 white gelatin hard capsules containing titanium dioxide (3.5%). The product contained 100 mg of effective 7432-S per capsule.

Comparative Examples 3-6 (Examples 11-14) The capsule of each of Examples 11-14 was labeled prior to attaching the closure gelatin solution like the capsules in Comparative Examples 3-6 in the following experiments.

is Capsule tests

The following experiments show the stability of the structure, the observations have been made under HPLC conditions: column = polygosil 6010C_ 134mm x 250 mm (M. Nagel &Col.); mobile phase = aqueous 0.05M ammonium acetate / methanol (96/4); flow rate = 20 1.5 ml / min .; internal standard = nicotinamide and UV assay 254 nm.

Test 1

The capsule (10 capsules each) was placed in a 500 ml glass vial, sealed and kept in a chamber at 45 ± 1 ° C.

The concentration of 7432-S was determined every month for 4 months according to HPLC. The concentration in Table 2 indicates the percentage shelf life compared to the concentration of freshly prepared capsules.

30

The unsealed capsule - whether or not an antioxidant was used as a stabilizer - was apparently more unstable compared to the capsule of the present invention.

• · «17 95349

Table 2

Capsule Content (%)

Month 1234

Invention Example 9 99.4 96.5 94.2 91.8 Example 10 98.0 95.8 93.4 91.2 Comparison Comparative Example 1 96.7 93.0 86.3 81.4

Comparison example. 2 94.5 89.4 87.3 80.4

Test 2

A capsule (10 capsules each) placed on white thick paper was kept in a chamber at 25 ± 1 ° C and irradiated with a 10,000 Lux fluorescent lamp. The concentration of 7432-S was determined every month for two months by HPLC and the color change in NBS color difference units using a color difference meter (Color studio, Nihon Densyoku Kogyo).

15

Table 3 shows the corresponding concentration and color change in NBS units compared to freshly prepared capsules.

20 Table 3

Capsule Concentration

Month 1 2

According to the invention Example 11 99.7 / 0.68 100.2 / 1.47 Example 12 100.1 / 1.35 100.0 / 2.85

Example 13 100.1 / 0.07 99.8 / 3.00

Eg 14 99.7 / 0.04 100.1 / 2.61

Comparison Comparative example 3 98.3 / 1.62 98.0 / 6.98

Comparison example. 4 97.0 / 4.06 96.1 / 7.39 comparative example. 5 98.8 / 3.23 98.3 / 8.12 Comparative Example 6 99.6 / 0.87 99.8 / 4.65 The NBS unit is U.S. Pat. Color difference unit according to National Bureau of Standards and 1 mil I I »M 1 25 18 95349. The following list shows a general idea regarding the values versus appearance.

From these experiments it can be concluded that the structures according to the present invention keep the 7432-S stable even under accelerated conditions (e.g. heat, irradiation) and 'protect it from discoloration. breaking of the fastening belt.

10

List of NBS unit difference NBS unit difference 0-0.5 not significant 3.0 - 6.0 significant 0.5 - 1.5 mild 6.0 - 12.0 obvious is 1.5-3.0 significant> 12.0 large 20 *

Claims (2)

95349 Claim