Bioavailability of ibuprofen from matrix pellets based on the combination of waxes and starch derivatives

The bioavailability of ibuprofen from pellets based on microcrystalline wax and starch derivatives was tested. During the in vivo evaluation an oral dose of 300 mg ibuprofen was administered to healthy human volunteers. F-1 and F-2 pellets were filled into hard gelatin capsules and were formulated with 60% ibuprofen, 15% waxy maltodextrin and 25% wax (a mixture of Lunacera M(R) and Lunacera P(R) (ratio 7/3) in the case of F-1 pellets and pure Lunacera P(R) in case of the F-2 pellets). In vitro, t(50%) was 20 and 4 h for F-1 and F-2 pellets, respectively. Both formulations behaved in vivo as sustained release formulations with a HVDt50%cmax value of 6.4 and 5.6 h for F-1 and value of 6.4 and 5.6 h for F-1 and F-2, respectively. Bioavailability depended on the composition of the formulation as the C-max-values were 5.3 and 8.5 mu g/ml and the AUC(0-->24h)-values 49.0 and 75.6 mu g x h/ml for the F-1 and F-2 pellets, respectively. The bioavailability of a chewable tablet, made of F-3 pellets (30% ibuprofen, 40% drum dried corn starch and 30% Lunacera P(R)) and showing an immediate in vitro drug release, was similar to the bioavailability of an ibuprofen suspension. The C-max and AUC(0-->24h) of F-3 pellets were 31.9 mu g/ml and 121.1 mu g x h/ml, respectively. These data demonstrate that pellets based on the combination of microcrystalline wax and starch derivatives can be used to formulate sustained as well as immediate release formulations. (C) 1998 Elsevier Science B.V. All rights reserved.