The bioavailability of seven commercially available rectal aminophylline suppositories

Abstract

The bioavailability and thein vitro parameters of seven aminophylline 360 mg suppositories were compared with an oral hydroalcoholic solution of aminophylline as reference, using cross-over designs in groups of four subjects in single dose experiments. Plasma concentrations were followed for eight hours after drug administration. Four products gave extents of bioavailability of less than 80% of the reference solution. A dissolution test gave results which did not correlate well with the bioavailability results. It was concluded that no satisfactory plasma levels can be reached with the examined dose of aminophylline after single administration of one suppository.

Calculation of the steady-state concentration was performed as well as a graphic simulation of the plasma concentration-time curves, after repeated administration; it was demonstrated that with most of the suppositories no sufficiently high level could be obtained after three doses per day.