GB1595057A - Pharmaceutical combination - Google Patents

Description

(54) PHARMACEUTICAL COMBINATION (71) We, THE WELLCOME FOUNDATION LIMITED, of 183-193 Euston Road, London, NW1, a Company incorporated in England, do hereby declare that the invention for which we pray that a patent may be granted to us, and the method by which it is performed, to be particularly described in and by the following statement: The present invention relates to a novel combination comprising an antiplatelet aggregatory substance and an anti-oxidant, a formulation containing such a combination, a method of preparing such formulations, and to the use of the combination in medicine.

The Applicants have discovered a naturally occurring prostaglandin, prostacyclin (PGI2; PGX) having the structure shown in formula (I) below (X=OH) is implicated in the biological mechanisms giving rise to intravascular thrombosis, gastroinestinal disorders, vasodilation, and bronchodilation.

They have also found how certain enzymes and other naturally occuring substances are implicated in the enzymic processes associated with the formation of PGX in body tissues, and as a result of these discoveries now provide a combination of substances useful in the prophylaxis or treatment of the above conditions.

PGX is located in a variety of body tissues including vascular, lung and stomach tissues. The notable biological property of PGX is its anti-aggregatory action on blood platelets at low concentrations, a property shared by other compounds, including those of formuh(II) hereinbelow.

The metabolic relationship of PGX to other prostaglandins is believed to be that shown in the following chart:

cell wall phospholipids (phospholipase A2J Arachidonic acid & arachiJonic acid other fatty acids OXIDATION (a cyclo-oxyenase) 'Y I lipid peroxides PGG2 and PGH2 (thromboxane synthetase) PGX synthetase g 8 t PGX Thromboxane A2 YI 6-keto PGF1 Thromboxane B2 The prostaglandin endoperoxides (PGG2 and PG H2) are produced from arachidonic acid by a cyclo-oxygenase enzyme, and are converted both into PGX by PGX synthetase and into thromboxane A2 by thromboxane synthetase. While PGX has potent anti-aggregatory activity, thromboxane A2 is pro-aggregatory, and the inhibition of thromboxane synthetase would both stimulate the formation of PGX and prevent the formation of thromboxane A2.

Arachidonic acid and other fatty acids undergo oxidation in the blood to produce lipid peroxides which inhibit the formation of PGX by the enzyme PGX synthetase. The use of an anti-oxidant to minimise the formation of lipid peroxides would in turn minimise the inhibition of PGX synthetase and promote the formation of the anti-aggregatory PGX.

The present invention accordingly provides a combination of substances (hereinafter referred to as "the Combination") which promote anti-aggregatory action on blood platelets comprising: (a) an anti-platelet aggregatory substance (as herein defined) together with (b) an antioxidant able to minimise the formation of lipid peroxides.

By an "anti-platelet aggregatory substance" is meant a substance whose mode of action is similar to that of the anti-platelet aggregatory action of PGX, itself one of the most notable features of which is the ability to reverse platelet aggregation and degrade existing thrombi.

Amongst the compounds which may be used in the combination of the present invention as anti-platelet aggregatory substances are compounds of the formula (I)

wherein X is OR' or NHR2 and Rt is hydrogen, alkyl or a pharmaceutically acceptable cation and R2 is hydrogen or alkyl.

Also amongst the compounds which may be used in the combination of the invention as anti-platelet aggregatory substances are the compounds of formula (11):

in which R is hydrogen, hydroxy, halo, cyano, amino, nitro, acyloxy or alkyl and R3 is hydrogen, alkyl or a pharmaceutically acceptable cation.

In the above alkyl has 1 to 4 carbon atoms and halo represents iodo, bromo or chloro.

Included amongst the compounds of formula (I) and formula.(II) are: Prostacyclin ((I), X=OH); Prostacyclin sodium salt ((I), X=ONa); Prostacyclin methyl ester r(I), X=OMe); and Dihydroprostacyclin [(II), R=R3=H; 9-deoxy-6S-9a-epoxy PGFta].

Compounds of formula (l) or (11) may be prepared by the methods described by Johnson et al J. Amer. Chem. Soc., 1977, 99, 4182. Compounds of the formula (I) may also be prepared by the method of Whittaker, Tet. Letters, 1977, 2805.

Prostacyclin (PGX) may also be prepared biosynthetically as described by Moncada et al, Nature, 1976, 263, 663.

Anti-oxidants which may be employed in the Combination according to the present invention include: a-tocopherol nicotinate; N,N'-diphenyl-p-phenylenediamine; Vitamin A, Vitamin C, Vitamin E and analogues thereof known in the art; 6 - ethoxy - 1,2 - dihydro - 2,2,4 trimethylquinoline; Retinol palpitate, and other suitable anti-oxidants known in the art as food additives such as the gallates.

(See for example: Dry J., et al, Rev. Prat., 1973, 23/59, 5263-5268; Korsan Bengsten L., et al., Thrombos, Diothes. haemorrh (Stuttg), 1974, 31, 505; and Washburn J. J., The Gerontologist, 1973, p. 436).

If desired, the Combination according to the present invention may include a thromboxane A2 synthetase inhibitor, for example: imidazol, l-methylirhidazole, benzydamine or a compound of formula (III)

wherein R4 and R7, are the same or different and each represents hydrogen or alkyl; R5 represents hydrogen, alkyl, chloro or methoxy; R6 represents hydrogen, alkyl or chloro; R8 represents an oxygen atom or the group'NH=; and R9 represents 2,3- or 4-pyridyl or the corresponding N-oxide derivative thereof.

R10 represents hydrogen, alkyl, cyclohexyl, phenyl, 4-fluorophenyl, 4-chlorophenyl or 4-methoxyphenyl.

A particularly valuable compound of formula (III) in respect of its thromboxane A2 synthetase inhibitory properties is 3 - (2 - isopropyl) - indolyl 3 - pyridyl ketone The compounds of formula (III) may be prepared as described in U.K. Patent Specification No. 1,318,300.

In our copending Patent Application 42280/76 (Serial No. 1,595,056) we describe and claim combinations of substances for promoting an anti-aggregatory effect on blood platelets comprising an anti-platelet aggregatory substance and a thromboxane synthetase inhibitor.

The Combination is useful whereever it is desired to inhibit platelet aggregation, to reduce the adhesive character of platelets, and to treat or prevent the formation of thrombi in mammals, including man. For example, the Combination is useful in the treatment and prevention of myocardial infarcts, to treat and prevent post-operative thrombosis, to promote patency of vascular grafts following surgery, and to treat complications of arteriosclerosis and conditions such as atherosclerosis, blood clotting defects due to lipemia, and other clinical conditions in which the underlying etiology is associated with lipid imbalance or hyperlipidemia.

The Combination is usef;rgs an additive to blood, blood products, blood substitutes, and other fluids which are used in artifical extra corporeal circulation and perfusion of isolated body portions, e.g., limbs and organs, whether attached to the original body, detached and being preserved or prepared for transplant, or attached to a new body. It may also be used in laboratory animals, e.g., cats, dogs rabbits, monkeys and rats, for these purposes in order to develop new methods and techniques for organ and limb transplants.

While it is preferred to administer the Combination as a mixture of ingredients for the purpose indicated above, the ingredients may be administered concurrently or sequentially, either as the raw chemical or separate pharmaceutical formulations of each ingredient.

The Combination is useful in mammals, including man, to reduce and control excessive gastric secretion, thereby reducing or avoiding gastrointestinal ulcer formation, and accelerating the heating of such ulcers already present in the gastrointestinal tract.

The Combination also exhibits a vasodilatory action on blood vessels and therefore has a particular utility as an anti-hypertensive for the treatment of high blood pressure in mammals, including man. The Combination affects the biochemical co-operation between platelets and vascular endothelium which contributes to the repair of vascular endothelium, and may be used to promote wound healing in mammals, including man.

The Combination exhibits a dilatory action on the bronchi and therefore has a particular utility as a bronchodilator for the treatment of prophylaxis of bronchitis and bronchial asthma in mammals, including man.

The Combination preferably contains the anti-platelet aggregatory substance in an amount of 25% to 75% (w/w), the antioxidant in an amount of 10% to 50% (w/w) and the thromboxane A2 synthetase inhibitor (when present) in an amount of 10% to 75% (w/w).

When the Combination contains only an anti-aggregatory substance and an antioxidant, the anti-aggregatory substance is preferably present in an amount of 10% to 90% (w/w), and the anti-oxidant in an amount of 10% to 90% (w/w).

The amount of the Combination required (hereinafter referred to as the active ingredient) for therapeutic effect will vary with the route of administration, and the nature of the condition under treatment. In general a suitable dose for a mammal of the Combination will lie in the range of 0.5 to 300 mg per kg body weight.

While it is possible for the Combination to be administered as a simple mixture of components it is preferable to present it as a pharmaceutical formulation. The formulations, both for veterinary and for human medical use, of the present invention comprise the active ingredient, as above defined, together with one or more acceptable carriers therefor and optionally other therapeutic ingredients.

The carrier(s) must be 'acceptable' in the sense of being compatible with the other ingredients of the formulation and not deleterious to the recipient thereof.

Formulations which contain PGX or salts thereof are preferably non-aqueous and non-hydroxylic in nature. Unit doses or a formulation contain between 0.05 mg, and 1.5 g of the active ingredient.

Formulations include those suitable for oral, rectal, vaginal, intrapulmonary or parenteral (including subcutaneous, intramuscular and intravenous) administration.

The formulations may conveniently be presented in unit dosage form and may be prepared in conventional manner, for example, by bringing in association the active ingredient with the carrier which comprises one or more accessory ingredients. In general, the formulations may be prepared by uniformly and intimately bringing into association the active ingredient with liquid carriers or finely divided solid carriers or both, and then, if necessary, shaping the product into the desired formulation.

According to the present invention there are therefore provided: (a) a combination comprising an anti-aggregatory substance together with an antioxidant able to minimise the formation of lipid peroxides; (b) the preparation of such a combination by admixture of the components; (c) a pharmaceutical formulation containing the combination; (d) the preparation of such pharmaceutical formulations; (e) method for the treatment and/or prophylaxis of thrombosis in a non-human mammal or non-human mammalian tissues comprising the administration to the said mammal or tissue of the above-defined combination; (f) method for inducing vasodilation in a non-human mammal comprising the administration to the said mammal of the above-defined combination; (g) method for the prophylaxis and/or treatment of gastric lesions in a nonhuman mammal, comprising the administration to the said mammal of the abovedefined combination; (h) method for the treatment of wounds in a non-human mammal comprising the administration to the said mammal of the above-defined combination.

The following Examples are provided by way of an illustration of the present invention and should in no way be construed as constituting a limitation thereof.

EXAMPLES Tablets containing the following ingredients were prepared by standard pharmaceutical procedures: (a) Dihydroprostacyclin 200 mg Imidazole 200 mg Vitamin E 100 mg (b) Prostacyclin methyl ester 450 mg 3-(2-isopropyl)-indolyl-3-pyridyl ketone 450 mg a-tocopherol nicotinate 100 mg (c) Prostacyclin methyl ester 800 mg 6-Ethoxy-1,2-dihydro-2,2,4-trimethylquinoline 200 mg WHAT WE CLAIM IS: 1. A combination of substances which promote an anti-aggregatory action on blood platelets comprising: (a) an anti-platelet aggregatory substance (as herein defined) and (b) an anti-oxidant able to minimise the formation of lipid peroxides.

2. A combination as claimed in Claim 1 in which the anti-platelet aggregatory substance is a compound of formula-(I)

wherein X is OR' or NHR2; R1 is hydrogen, alkyl or a pharmaceutically acceptable cation and R2 is hydrogen or alkyl.

3. A combination as claimed in Claim 2 in which, in the compound of formula (I), X is OR' and R' is H.

4. A combination as claimed in Claim 2 in which, in the compound of formula (I), X is OR' and R' is Na.

5. A combination as claimed in Claim 2, in which, in the compound of formula (I), X is OR' and R' is CH3.

6. A combination as claimed in Claim 1 in which the anti-platelet aggregatory substance is a compound of formula (II)

wherein R is hydrogen, hydroxy, halo, cyano, amino, nitro, acyloxy or alkyl and R3 is hydrogen, alkyl or a pharmaceutically acceptable cation.

7. A combination as claimed in Claim 6, wherein the anti-platelet aggregatory substance is 9-deoxy-6S-9a-epoxy PGF1a.

8. A combination as claimed in any one of the preceding claims, wherein the antioxidant is selected from cr-tocopherol nicotinate; N,N' - diphenyl - pphenylenediamine; Vitamin A, Vitamin C; Vitamin E; 6 - ethoxy - 1,2 - dihydro 2,2,4 - trimethylquinoline and Retinol palmitate.

9. A method for the preparation of a combination as defined in Claim 1 which comprises admixing compounds (a) and (b) as defined in Claim 1.

10. A pharmaceutical formulation comprising a combination as defined in any one of Claims 1 to 8 together with a pharmaceutically acceptable carrier therefor.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (24)

1. **WARNING** start of CLMS field may overlap end of DESC **.

   (a) Dihydroprostacyclin 200 mg Imidazole 200 mg Vitamin E 100 mg (b) Prostacyclin methyl ester 450 mg

   3-(2-isopropyl)-indolyl-3-pyridyl ketone 450 mg a-tocopherol nicotinate 100 mg (c) Prostacyclin methyl ester 800 mg 6-Ethoxy-1,2-dihydro-2,2,4-trimethylquinoline 200 mg WHAT WE CLAIM IS: 1. A combination of substances which promote an anti-aggregatory action on blood platelets comprising: (a) an anti-platelet aggregatory substance (as herein defined) and (b) an anti-oxidant able to minimise the formation of lipid peroxides.
2. 2. A combination as claimed in Claim 1 in which the anti-platelet aggregatory substance is a compound of formula-(I)

   wherein X is OR' or NHR2; R1 is hydrogen, alkyl or a pharmaceutically acceptable cation and R2 is hydrogen or alkyl.
3. 3. A combination as claimed in Claim 2 in which, in the compound of formula (I), X is OR' and R' is H.
4. 4. A combination as claimed in Claim 2 in which, in the compound of formula (I), X is OR' and R' is Na.
5. 5. A combination as claimed in Claim 2, in which, in the compound of formula (I), X is OR' and R' is CH3.
6. 6. A combination as claimed in Claim 1 in which the anti-platelet aggregatory substance is a compound of formula (II)

   wherein R is hydrogen, hydroxy, halo, cyano, amino, nitro, acyloxy or alkyl and R3 is hydrogen, alkyl or a pharmaceutically acceptable cation.
7. 7. A combination as claimed in Claim 6, wherein the anti-platelet aggregatory substance is 9-deoxy-6S-9a-epoxy PGF1a.
8. 8. A combination as claimed in any one of the preceding claims, wherein the antioxidant is selected from cr-tocopherol nicotinate; N,N' - diphenyl - pphenylenediamine; Vitamin A, Vitamin C; Vitamin E; 6 - ethoxy - 1,2 - dihydro 2,2,4 - trimethylquinoline and Retinol palmitate.
9. 9. A method for the preparation of a combination as defined in Claim 1 which comprises admixing compounds (a) and (b) as defined in Claim 1.
10. 10. A pharmaceutical formulation comprising a combination as defined in any one of Claims 1 to 8 together with a pharmaceutically acceptable carrier therefor.
11. 11. A formulation as claimed in Claim 10, wherein the carrier is a solid.
12. 12. A formulation as claimed in Claim 10, wherein the carrier is a liquid.
13. 13. A formulation as claimed in Claim 10 in a form suitable for oral, parenteral, rectal, vaginal, or intrapulmonary administration.
14. 14. A formulation as claimed in Claim 10 or Claim 11 in tablet form.
15. 15. A formulation as claimed in any one of Claims 10 to 14 in unit dosage form.
16. 16. A formulation as claimed in Claim 15 containing from 0.05 mg to 1.5 g of total active ingredient.
17. 17. A method for the preparation of a pharmaceutical formulation as defined in any one of Claims 10 to 16 comprising bringing components (a) and (b) as defined in Claim I into admixture with the said pharmaceutically acceptable carrier.
18. 18. A method for the treatment or prophylaxis of thrombosis in a non-human mammal or non-human mammalian tissue comprising the administration to the said mammal or tissue of a combination as defined in any one of Claims I to 8.
19. 19. A method for inducing vasodilation in a non-human mammal comprising the administration to the said mammal of a combination as defined in any one of Claims 1 to 8.
20. 20. A method for the prophylaxis or treatment of gastric lesions in a nonhuman mammal comprising the administration to the said mammal of a combination as defined in any one of Claims 1 to 8.
21. 21. A method for the promotion of wound healing in a non-human mammal comprising the administration to the said mammal of a combination as defined in any one of Claims .1 to 8.
22. 22. A method of inducing bronchodilation in a non-human mammal comprising the administration to the said mammal of a combination as defined in any one of Claims 1 to 8.
23. 23. A method as claimed in any one of Claims 18 to 22, wherein the combination is administered in an amount of from 0.5 to 300 mg per kilogram body weight.
24. 24. A combination as claimed in Claim 1 substantially as herein before described with reference to Example (c).