Process for producing 1-methyl-beta-oxo-alpha-(phenyl-carbamoyl)-2-pyrrolpropionitrile tromethamine salt and pharmaceutical compositions comprising such compound

(42) Date of commencement of the patent: 15.10.1989 (45) Date of issue: 10. 5.1990 (30) Priority:

18.12.1987 US PCT / US87 / 03413.

(56) References: US Pat. No. 4,256,759 (51) Int.⁵ : C07D 207/337 A61K 31/40 (73)

CIBAGIGY AG

CH-4002 BASEL (CH).

(54) TROMETHAMINE SALT OF I-METHYL-BETA-OXO-ALPHA (PHENYLCARBAMOYL) -2-PYRROL-PROPIONITRIL (57) The present invention relates to the novel pharmaceutically acceptable tromethamine salt of 1-methyl-beta-oxo-alpha (Phenylcarbamoyl) -2-pyrrolpropionitrile and pharmaceutical preparations containing this compound and use of this compound or pharmaceutical preparations thereof for the treatment of inflammatory and arthritic diseases.

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No. 390,437. U.S. Patent 4,256,759 discloses 1-methyl-octa-oxo-alpha (phenylcarbamoyl) -2-pyrrolepropionitrile of the formula I

II

<img file="AT390437B_D0001.tif" />

(D) This compound may also be present in tautomeric enol form represented by formula Ia

<img file="AT390437B_D0002.tif" />

is reproduced.

U.S. Patent 4,256,759 discloses salts with bases, particularly therapeutically acceptable salts with bases derived from an alkali metal, alkaline earth metal, copper or zinc hydroxide; Ammonia, mono-, di- or tri (alkyl or hydroxyalkyl) -amines, alkyleneamines or alkylenediamines, such as sodium, potassium, magnesium, ammonium, mono-, di- or tri- (methyl, ethyl or hydroxyethyl) - ammonium, pyrrolidinium, ethylenediammonium or morpholinium salts or their various hydrates

Specifically, only the sodium, potassium, calcium and trishydroxyethylammonium (trielhanolamine) salt of the compound of formula I are described in the specification of the above US patent. The sodium, potassium and calcium salts are not crystalline.

It has been found that the tertiary amine triethanolamine can be chemically converted to N-nitrosodiethanolamine, a potentially carcinogenic substance. Several concerns have been expressed about trichloranolamine salt as a pharmaculoic acid. These are based on the assumption that triethanolamine can somehow metabolize in the mammals to N-nitrosodiethanolamine.

The present invention has for its object to provide a new salt of 1-methyl-beta-oxo-alpha (phenylcarbamoyl) -2-pyrrolpropionitrile, which is suitable for the treatment of inflammatory and arthrilic diseases and has advantageous physical and biochemical properties.

This object is achieved by providing the novel pharmaceutically acceptable tromelamine salt of 1-methyl-beta-oxo-alpha (phenylcarbamoyl) -2-pyrrolpropionitrile and pharmaceutical preparations containing this salt and their use for the treatment of inflammatory and arthritic diseases ,

Tromethamine is the primary amine tris (hydroxymethyl) aminomethane, also called 2-amino-2- (hydroxymethyl) 1,3-propanediol, and described in the Merck Index, 10th Edition, page 1395.

It is not known that the primary amine tromethamine is chemically converted to N-nitrosated derivatives.

More particularly, the present invention relates to the 1: 1 tromelamine salt of 1-methyl-beta-oxo-alpha (phenylcarbamoyl) -2-pyrrolidopropionitrile represented by Formula II (II).

-2Nr. 390 437

The new salt of formula II exhibits antiinergic and analgesic effects. The salt of formula II also eliminates other effects, such. As inhibition of cartilage matrix degradation and immunomodulating properties, and is thus very well suited for the treatment of arlritic diseases.

The salt of formula II according to the invention is well tolerated at the therapeutic doses and largely free of undesirable side effects.

The salt of formula II also shows lower toxicity than the preclinical compound of formula I or the previously known triethanolamine salt thereof. At a dose of 2.4 millimoles / kg po (932 mg / kg po) tromethamine salt of formula II, no deaths (0/10 animals) were found, as opposed to 50% mortality at an equimolar dose of 2.4 millimoles / kg po (1000 mg / kg po) triethanolamine salt of the compound of formula I and 40% mortality at an equimolar dose of 2.4 millimoles / kg po (641 mg / kg po) of the free acid of formula I.

The new erfmdungsgemäße salt of formula II does not form N-nitroso-containing metabolites.

Due to the above-mentioned properties, the novel salt of formula II, alone or in combination, is particularly useful for the treatment of rheumatoid arthritis and osteoarthritis in mammals, including humans.

The pharmacological properties, primarily anti-inflammatory, analgesic, antirheumatic, immunomodulating and antiarrhythmic effects, can be demonstrated in in vitro or in vivo experiments. In the latter, mammals, e.g. B. Rats, mice, guinea pigs or dogs used as test objects. The compound may be administered to the animals enlerally, preferably orally, parenterally, e.g. B. subcutaneous or intravenous, or topical, e.g. B. in the form of aqueous solutions or suspensions. The dose used may range from about 0.1 and 100 mg / kg / day, preferably between about 1 and 50 mg / kg / day. The assays chosen for the aforementioned effects are classical in vivo experimental methods, such as the rat carrageenin paw edema or adjuvant drug test, and the dog synovium test.

O

For in vitro test methods, concentrations of the formula II compound range from about 1 x 10 '° M to 1 x 10'.⁴ M, preferably between about 1 x IO '⁷ M to 1 x 10⁴ M. Such tests are z. B. the in vitro neutral protease inhibition described in Arthritis Rheum. 17,47 (1974), or inhibition of neutrophilic chemotaxis described in Ann. NY Acad. Sci., 256, 177 (1975); or decrease in leucozylene adherence described in Amer. J. Med. 61,597 (1976).

Inhibition of chemotactic activation of neutrophils can be determined in vivo by measuring the inhibition of neutrophil accumulation in inplanted carrageenin in impregnated polyurethane sponges upon oral administration of the compound to the rat.

The immunological effects can be determined on BCG-immunized animals. The enhancement of cell-mediated immunity is determined in vitro by measuring the increased chemotaxis of macrophages isolated from BCG-immunized rats. The enhancement of cell-mediated immunity is assessed in vivo on the BCG-immunized arlritic rat by measuring the delay in the hypersensitivity reaction, essentially as described in Current Therapeutic Research 30, p. 34 (1981).

The determination of the effect on cartilage-matrix degradation can be shown in the cartilage synovial tissue co-cultivation system, a model for the study of cartilage-matrix degradation, which is carried out as follows:

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The proteoglycan matrix of bovine nasal septum cartilage is invitro in vitro ^JJS-installation in qc

Glycosaminoglycans marked. For this purpose, the cartilage slices are incubated in sulfate-free medium containing SN sodium sulfate overnight. Thereafter, the ^ S-labeled cartilage slices are co-cultured with planimates of normal synovial tissue for 4 days in Mulli-WeH tissue culture plates. At the end of this incubation period, the radioactivity is measured from a 100 μΙ aliquot of the medium. Then the cartilage clusters are hydrolyzed and the radioactivity determined therein. From this it can be calculated which part of the ^^ S-labeled glycosaminoglycane was released into the medium during Co-Kullur; By comparing treated and untreated (= control) cultures, the percent inhibition of matrix destruction can be calculated.

The inhibition of cartilage-matrix degradation can also be determined by measuring the inhibition of cartilage disruption by neutral protease derived from human blood leukocytes.

The crystalline tromethamine salt of the formula II according to the invention is prepared by reacting the compound of the formula I

(D

X

-3Nr. 390 437 preferably with an equimolar amount or with a slight excess of tromethamine in the presence of a suitable inert solvent, such as an alcoholic or ethereal solvent or mixture thereof, so that the salt crystallizes from the solution. Suitable solvents are, for. B. Ethanol, isopropanol, a mixture of tetrahydrofuran and methyl t-butyl ether, or a mixture of ethanol and toluene. The salt formation is generally carried out in the more polar solvent, and the second less polar solvent is added at elevated temperature and in sufficient quantity for the crystallization of the product.

The starting material of the formula I is known from US Pat. No. 4,256,579 and can be prepared as described there.

The tromethamine salt of the formula II according to the invention can be obtained in the form of its hydrate or include other solvents used for the crystallization.

The pharmaceutical compositions of the present invention containing an effective amount of the active ingredient of formula II together with one or more pharmaceutically acceptable carriers are enteral, preferably oral or rectal, and parenteral mammals, including humans, for the treatment of inflammatory / arthritic diseases, such as osteoarthritis and rheumatoid arthritis, and immunological diseases.

The pharmacologically active salt of formula II according to the invention is inkoiporiert in pharmaceutical preparations containing an effective amount thereof in admixture with excipients which are suitable for enteral, parenteral or topical administration. Preferably, tablets and gelatin capsules containing the active ingredient together with (a) diluents, e.g. B. Lactose, dextrose, raw sugar, mannitol, sorbitol, cellulose, hydroxypropylmethylcellulose and / or glycine; (b) lubricants, e.g. B. Silica, talc, stearic acid or salts thereof, such as magnesium or calcium stearate and / or polyethylene glycol; respectively. Tablets also contain (c) excipients, e.g. B. Magnesium aluminum silicate, starch paste, gelatin, tragacanth, methyl cellulose, sodium carboxymethyl cellulose and / or polyvinyl pyrrolidone; and if desired (d) disintegrants, e.g. B. Starches, agar, alginic acid or the sodium salt thereof, and / or effervescent mixtures; and / or (e) adsorbents, dyes, flavorings and sweeteners. Injectable preparations are preferably isotonic aqueous solutions or suspensions, and suppositories or topical lotions are primarily made from fat emulsions or suspensions. The preparations may be sterilized and / or contain adjuvants, such as preservatives, stabilizers, wetting agents or emulsifiers, solubilizers, salts for regulating the osmotic pressure and / or buffers. The present pharmaceutical preparations, which, if desired, may contain other therapeutically valuable substances are prepared in a conventional manner, for. B. by means of conventional mixing, granulating or coating methods, and containing from about 0.1 to 75%, in particular from about 1 to 50%, of the active substance.

The present invention furthermore relates to the use of the compound of the formula II according to the invention for the treatment of inflammatory and arthritic diseases, such as rheumatoid arthritis or osteoarthritis in mammals, People included, by adding an effective amount of the compound of the formula Π according to the invention or a pharmaceutical preparation, which contains an effective amount of the compound of the formula II according to the invention together with one or more pharmaceutically acceptable excipients, the mammals, People included, administered

The dose of the active substance used depends on species, on body weight, age and individual condition, and on the mode of administration.

The single dose for mammals with 50 to 70 kg weight is between about 100 and 500 mg of the active substance.

The following examples serve to illustrate the invention and should not be construed as limiting. Temperatures are given in degrees centigrade. Unless defined otherwise, evaporation is carried out under reduced pressure, preferably between about 15 and 100 mm Hg. The structure of the product is confirmed by analytical methods, in particular spectroscopic characteristics (eg MS, IR, NMR) and elemental analysis.

example 1

A suspension of 10.09 g of 1-methyl-beta-oxo-alpha- (phenylcarbamoyl) -2-pyrrolepropionitrile in 160 ml of tetrahydrofuran is heated to reflux, the resulting solution is cooled to 50-55 °, and with 5.22 g of tromethamine added. The resulting mixture is stirred at reflux for 30 minutes, cooled to about 45-50 °, then treated with charcoal, stirred until room temperature is reached and filtered with Hyflo. The resulting solution is reduced to a volume of about 50 ml; 40 ml of methyl t-butyl ether added slowly and the mixture stirred for 2 hours at 15-20 °. The crystalline product is collected, washed with a 1: 1 mixture of tetrahydrofuran and methyl t-butyl ether, dried at 80 ° C under vacuum overnight. The tromethamine salt of 1-methyl-1-beta-oxo-alpha (phenylcarbamoyl) -2-pyrrolpropionitrile (1: 1), m.p. 163-165 °.

-4Nr. 390 437

Example 2

A suspension of 13.36 g of 1-methyl-beta-oxo-alpha- (phenylcarbamoyl) -2-pyrrolpropionitrile and 6.06 g of tromethamine in 100 ml of ethanol is refluxed for 30 minutes, the solution is cooled to room temperature, treated with charcoal , filtered and reduced at a temperature below 60 ° to a volume of about 45 ml. The resulting solution is heated to about 50-55 °, 100 ml of toluene added slowly within half an hour with stirring, the resulting mixture slowly cooled for one hour up to about 15 ° and stirred for one hour at 15 °. The resulting crystalline product is filtered, washed with toluene, dried at 70-80 ° within 24 hours under vacuum. The tromethamine salt is obtained from 1-methyl-beta-oxo-alpha- (phenylcarbamoyl) -2-pyrrolpropionitrile. The product is identical to that of Example 1. A large batch of product can be obtained by evaporation of the mother liquor to dryness and crystallization from ethanol: toluene (1: 2) as described above.

Example 3

To a suspension of 13.85 g of 1-methyl-beta-oxo-alpha- (phenylcarbamoyl) -2-pyrrolepropionitrile in 350 ml of ethanol is added 6.1 g of tromethamine. The suspension is heated until a solution is obtained and the volume is reduced to about 75 ml. The solution is cooled until the product crystallises, the salt obtained is separated off, washed with ethanol / ether and dried. The tromethamine salt of 1-methyl-beta-oxo-alpha (phenylcarbamoyl) -2-pyrrolepropionitrile (1: 1) is obtained. The product is identical to that of Example 1.

Example 4

Preparation of 10,000 tablets each containing 250 mg of the active substance

ingredients:

Tromethamine salt of 1-methyl-beta-oxo-alpha (phenylcarbamoyl) -2-pyrrolepropionitrile 2,500.0 g colloidal silica 20.0 g microcrystalline cellulose 465.0 g

Hydroxypropylmethylcellulose 160.0 g of cross-linked polyvinylpyrrolidone 200.0 g

Magnesium stearate 35.0 g purified water qs

The active substance, the silica and the hydroxypropylmethylcellulose are mixed in a suitable mixer within about 20 minutes. The mixture is granulated with a sufficient amount of water. The wet granules are ground in a mill, forced through a # 5 sieve, dried at 35 ° within 6 hours, then ground in a mill and forced through a # 2 sieve. The resulting granules, cellulose and polyvinylpyrrolidone are mixed together in a suitable mixer within 15 minutes, the magnesium stearate (initially driven through a # 30 sieve) is added and mixed with the above within about 5 minutes. The resulting granules are then added Pressed tablets. The tablets may then be coated with a film jacket if desired.

Example 5

acute toxicity

A single equimolar dose of each compound is administered as a 3% strength oral suspension to 5 female and 5 male Sprague-Dawley rats. Animals are observed for 15 days. The comparable occurrence of mortality in the free acid of the formula I, the triethanolamine salt thereof and the tromethamine salt of the formula Π is as follows:

a) for 1-methyl-beta-oxo-alpha- (phenylcarbamoyl) -2-pyrrolepropionitrile (I, mol. wt: 267.28)

dose

mortality

<td>Millimoles / kg</td><td>mg / kg</td><td>male</td><td>Female</td>

<td>1.2</td><td>321</td><td>0/5</td><td>0/5</td>

<td>2.4</td><td>641</td><td>2.5</td><td>2.5</td>

<td>3.6</td><td>962</td><td>4.5</td><td>4.5</td>

-5Nr. 390 437

b) for the triethanolamine salt of 1-methyl-beta-oxo-alpha- (phenylcarbamoyl) -2-pyrrolpropionitrile (mol.wL: 416.49)

Dose mortality

<td>Millimoles / kg</td><td>mg / kg</td><td>male</td><td>Female</td>

<td>1.2</td><td>500</td><td>0/5</td><td>0/5</td>

<td>2.4</td><td>1000</td><td>2.5</td><td>3.5</td>

<td>3.6</td><td>1500</td><td>5.5</td><td>5.5</td>

c) for the tromethamine salt of l-methyl-beta-oxo-alpha- (phenylcarbamoyl) -2-pyrrolpropionitrile (Π, mol.

<td colspan="4">wL: 388.41)</td>

<td>dose</td><td colspan="3">mortality</td>

<td>Millimoles / kg</td><td>mg / kg</td><td>male</td><td>Female</td>

<td>1.2</td><td>466</td><td>0/5</td><td>0/5</td>

<td>2.4</td><td>932</td><td>0/5</td><td>0/5</td>

<td>3.6</td><td>1398</td><td>5.5</td><td>5.5</td>