Pharmaceutical compositions based on diltiazem and lysine acetylsalicylate

Abstract

Pharmaceutical composition containing both diltiazem and lysine acetylsalicylate exhibits enhanced platelet aggregation inhibitory properties.

Description

The present invention relates to pharmaceutical compositions based on diltiazem and lysine acetylsalicylate, the compositions being intended for use in the treatment of platelet aggregation.

Diltiazem or cis(+)-3-acetyloxy-5-[2-dimethylamino)ethyl]-2,3-dihydro-2-(4-methoxy phenyl)-1,5-benzothiazepin-4(5H)-one of formula ##STR1## is known for its antianginal, antihypertensive, calcium antagonistic and platelet aggregation inhibitory activities.

Lysine acetylsalicylate (LAS), of formula ##STR2## is known for its analgesic, anti-inflammatory and platelet aggregation inhibitory properties.

I have found that, surprisingly, the platelet aggregation inhibitory properties of each of these compounds are potentiated when the two compounds are used together.

The pharmaceutical compositions of the invention were subjected to a series of pharmacological trials.

The compositions were tested in vitro in the following manner:

the compounds are administered, either alone or in combination, to a suspension of platelets and plasma present in the 250-.mu.l cells of an aggregometer, two minutes before adding 10 .mu.g of arachidonic acid, an agent which induces platelet aggregation. The aggregation is followed in a twin-channel chronological aggregometer according to the method of Born, Journal of Physiology, 168, 178-195 (1963).

The results obtained are given in Tables 1 and 2.

TABLE 1______________________________________ % inhibition of plateletConcentration Concentration aggregationof LAS of diltiazem LAS Diltiazem LAS +.mu.M .mu.M alone alone diltiazem______________________________________10 200 6 3 8820 200 13 12 6650 200 25 9 7250 200 9 6 7920 400 7 27 9650 400 9 27 100______________________________________ LAS = lysine acetylsalicylate. TABLE 2______________________________________ Con- % inhibition of plateletConcentration centration aggregationof diltiazem of LAS Diltiazem LAS Diltiazem +.mu.M .mu.M alone alone LAS______________________________________200 10 3 6 88200 20 12 13 66400 20 27 7 96200 50 9 25 72400 50 27 9 100______________________________________

The compositions of the invention were tested in vivo in the following manner:

diltiazem at a dose of 10 mg/kg and LAS at a dose of 1 mg/kg are administered orally, either alone or in combination, to five groups of two rats. After one hour, blood samples are drawn. Suspension of plasma and platelets are then prepared and placed in the 250-.mu.l cells of an aggregometer two minutes before adding arachidonic acid (200-250 .mu.g/ml). The aggregation is followed in a twin-channel chronological aggregometer according to the method of Born.

The results are given in Table 3.

TABLE 3______________________________________ % inhibition of platelet aggregationDose of Dose of (mean of 5 experiments)LAS diltiazem LAS Diltiazem LAS +mg/kg p.o. mg/kg p.o. alone alone diltiazem______________________________________1 10 8 9 81______________________________________

Results show that the combination of lysine acetylsalicylate and diltiazem produces a platelet aggregation inhibitory effect which is significantly larger than the sum of the effects engendered by each of the compounds administered separately.

There is potentiation of the platelet aggregation inhibitory activity of each of the compounds, LAS and diltiazem, by the other.

The pharmaceutical compositions of the invention can contain from 3 to 60 mg of diltiazem and from 10 to 300 mg of LAS per unit dose.

The pharmaceutical compositions of the invention can be presented in any form suitable for oral or parenteral administration, in combination with any suitable excipient.

The pharmaceutical compositions of the invention can be used for the treatment of coronary and cerebrovascular thrombosis, peripheral vascular conditions, disorders of platelet aggregation and migraine.

The daily dosage can be from 2 to 3 unit doses.

Claims

1. A pharmaceutical composition which contains from 3 to 60 mg of diltiazem and from 10 to 300 mg of lysine acetylsalicylate per unit dose.