Pharmacokinetics and bioequivalence of two ibuprofen formulations

In an open controlled randomized cross-over study in 16 healthy male and female volunteers the bioavailability of ibuprofen (CAS 15687-27-1) sugar-coated tablets (Dolo-Dolgit) was tested versus film-coated tablets containing ibuprofen 600 mg. As it results from the AUC evaluation, the bioavailability of both preparations is very good and almost identical. The ibuprofen concentrations achieved after administration of the test preparation, however, are significantly higher (Cmax = 52.03 micrograms/ml) than those achieved after the reference preparation showing a Cmax of 40.32 micrograms/ml. The tmax of 1.0 h is also significantly shorter than after the reference preparation (tmax = 1.5 h). The t1/2 beta after both the test and the reference preparation is within the known range, i.e. 1.8 h and 1.4 h, respectively. Even in long-term treatment with high dosages, administered 3-4 times daily, there is no accumulation of the active ingredient. Concerning the therapeutic relevance, special attention is to be given to the different time-dependent drug concentrations in the central compartment and in the target compartment. Both the higher Cmax and the shorter tmax achieved following administration of the test preparation are of therapeutic relevance.