0100488763

open access

Version of Record

STUDIES ON SUSTAINED-RELEASE DOSAGE FORMS : IV. PHARMACOKINETICS AFTER RECTAL ADMINISTRATION OF NIFEDIPINE SUPPOSITORIES IN RABBITS

English (英語)

The Kobe journal of the medical sciences

31(3)

117-131

1985-06

The pharmacokinetics of nifedipine after intravenous injection and rectal administration of conventional suppositories and of sustained-release suppositories in rabbits were evaluated, based on the compartment model and statistical moment method. The plasma concentration-time curves following intravenous administration were described by a two-compartment model. The half-life of elimination phase was relatively short (t1/2β = 0.682 hr). Rectal absorption from the conventional suppository dosage form was rapid and the elimination from body was more rapid. The extent of bioavailability of three dose levels was about 62 - 80% on the average. After administration of sustained-release suppositories, the pharmacokinetic parameters were calculated using an equation which included three or four exponential function consistent with a two-compartment model. The apparent absorption rate (ka) of this dosage form was smaller than that of the conventional suppository, and the sustained effect was apparently attributed to the slow absorption process. From the results of the statistical moment analysis, it was found that the mean absorption time of the sustained-release suppository was about 6 times greater than that of the conventional suppository. That is, the dissolution process with this suppository was the rate-determining step.

sustained-release suppository

紀要論文