[The effect of certain active principles and excipients on the biodisposition of rectally administered acetylsalicylic acid in the rabbit].

In this work, we have studied in the rabbit, bioavailability of acetylsalicylic acid contained respectively in three forms of suppositories which are made as follows: for the first by only acetylsalicyclic acid (0.1 g); for the second by the association: acetylsalicylic acid (0.1 g) and phenobarbital (0.01 g); and for the third by acetylsalicylic acid (0.01 g), ascorbic acid (0.02 g) and thiamine chloride (0.002 g). It has been shown that ascorbic acid and thiamine chloride do not change the bioavailability of acetylsalicylic acid, while phenobarbital decreases it. In this work we have also compared two pharmaceutical forms of suppositories containing acetylsalicylic acid, ascorbic acid and thiamine chloride. In one of the two forms, acetylsalicylic acid is buffered by glycocolle. The study which consisted in giving the two forms to the rabbit rectally was concerned with the effect of glycocolle on the bioavailability of acetylsalicylic acid. It was shown that making glycocolle a buffer to acetylsalicylic acid resulted in an improved absorption as well as a delayed elimination of acetylsalicyclic acid. In this study too, we have evaluated the bioavailability of acetylsalicylic acid which is released from two types of suppositories containing respectively base witepsol W31 and base cocoa butter. In order to study this bioavailability whole suppositories were administered by rectal route to the rabbits after 24 hours of fasting (balanced crossover design with 15 days of interval after each study). Statistical analysis does not reveal any significant difference between the two forms of suppositories.