Relative bioavailability of commercially available ibuprofen oral dosage forms in humans.

Two human bioavailability studies were conducted to assess the in vivo performances of recently marketed 200-, 300-, and 400-mg ibuprofen capsules relative to the innovator's 300- and 400-mg tablets when administered as single oral 300- or 400-mg doses. An ibuprofen oral solution was also administered in each trial. Within each study, the products were equivalent to each other and to the oral solution with respect to the extent of ibuprofen absorption. Absorption rates, however, differed markedly among the products studied. Ibuprofen was more slowly absorbed from the 300- and 400-mg capsules than from the respective strength tablets. The 200-mg capsule exhibited an absorption rate comparable to the 400-mg tablet but more rapid than the 400-mg capsule. It was concluded that two of the duplicator's 200-mg capsules were bioequivalent to one of the innovator's 400-mg tablet. The duplicator's 300- and 400-mg capsules were bioinequivalent to the innovator's 300- and 400-mg tablets, respectively, due to their slower rates of absorption.