Comparative study of specific activity of rectal suppositories with clopidogrel

Abstract

One of the most effective platelet antiaggregants is clopidogrel, inhibiting platelet activation by selectively binding adenosine diphosphate (ADP) with specific receptors. However, in a number of clinical situations it is necessary to have a pronounced antithrombotic effect in the shortest possible time which gives rise to interest in the transmucose use of the drug, in particular, rectal route. The theoretical preconditions for the development of a rectal administration of clopidogrel are based on the data that the anti-aggregation effect of a substance is carried out by its main metabolite formed after “first hepatic passage”, while clopidogrel itself in this aspect is inactive. On the base of complex physico-chemical, pharmaceutical, biopharmaceutical, rheological and microbiological investigations, the rational composition of clopidogrel rectal dosage form – suppository on a hydrophilic base to prevent atherothrombotic events in patients with myocardial infarction, acute coronary syndrome, ischemic stroke, peripheral arterial occlusion, is proposed by the employees of the Department of Technology of Medications of the Zaporizhzhia State Medical University. The aim of the work is to investigate the specific activity of rectal suppositories with clopidogrel. Materials and methods. Experimental suppositories with clopidogrel 0,075 g for rectal administration were used as the objects in pre-line studies. The ability of clopidogrel to reduce the inhibitory effect of ADP on adenylate cyclase activity and decrease the number of binding sites for 2-methylthio-ADP (analogue of ADP) without altering the receptor topography is used as a base of the method of comparative study of its specific activity in the rectal dosage form (suppository) and in comparison with the reference medication Plavix (SANOFI WINTHROP INDUSTRIE, France) in the tablet form. Studies were performed on white non-linear rats of different sexes with different mass 150–210 g, aged 3.5–5.0 months. Results. Statistically significant differences in the inhibition of induced platelet aggregation were registered after 6 hours of rectal administration of clopidogrel and gastric administration of the reference medication, indicating the effectiveness of the rectal applicative transmucosal route for this active pharmaceutical ingredient (API). On the 5th day of administration, inhibition of induced platelet aggregation significantly increased, and that is supported by literature on the cumulative effect of clopidogrel in daily life. When comparing the digital material of the table, it is obvious that the rectal administration of clopidogrel is more effective in comparison with oral route which is probably due to the rapid delivery of API to the liver and the formation of an active metabolite of clopidogrel inhibiting the induction and spontaneous aggregation of platelets in human’s and animal’s blood. Obtained data provide with sound arguments for development of rectal suppositories with clopidogrel because in clinical care faster achievement of an anti-aggregation effect in patients with acute coronary syndrome is the primary task of clinical pharmacology and pharmacy. Conclusions. Using the biochemical model of pathology, it was established that the applicative semisolid medication of clopidogrel in the form of rectal suppository exhibited inductive anti-aggregation activity and its administration didn’t reveal any side effects and undesirable events. Rectal suppositories with clopidogrel have been shown to exhibit faster reliable anti-aggregation effect in comparison with intragastric administration.

Keywords

• atherothrombosis
• clopidogrel
• rectal suppositories
• specific activity