Bioavailability of ibuprofen from orally and rectally administered hydroxypropyl methyl cellulose capsules compared to corresponding gelatine capsules

The aim of the present study was to determine whether ther are any differen ces in the bioavailability of ibuprofen from hydroxypropyl methyl cellulose (HPMC) capsules (a new type of hard two-piece capsules) compared to hard g elatine capsules when they are administered orally and rectally. Two groups of eight healthy volunteers participated in randomised, cross-over, single -dose studies. One group administered capsules orally (HPMC and gelatine ca psules) and the other rectally. there were no statistically significant dif ferences between the calculated pharmacokinetic parameters (C-max, t(max), t(lag), AUC, MRT, C-max/AUC t(1/2)) after the oral administration of the HP MC and gelatine capsules. Following rectal administration, the t(lag) and C -max/AUC values for the HPMC and gelatine capsules were bioequivalent, but the rectally administered capsules could not be proven as bioequivalent, pr obably because of the greater variation in the pharmacokinetics. The study shows that HPMC capsules are comparable to gelatine capsules and thus a not eworthy alternative to gelatine capsules. However, attention should be paid to the time lag at the onset of absorption following rectal administration .