[Bioavailability of acetylsalicylic acid administered orally or rectally in the rabbit]

The aim of this study is to compare the bioavailability of acetylsalicylic acid administered rectally in suppositories form and orally in tablets form to the rabbit. Acetylsalicylic acid was given to 8 males rabbits rectally and orally in a balanced crossover design with 15 days of interval between each study. In blood samples, acetylsalicylic acid is determined by Trinder's method. It has been established that the rectal route has a faster absorption than the oral route however it displayed a more intense first pass effect than that of the oral route.