INVITRO AND INVIVO EVALUATION OF SUSTAINED-RELEASE SUSPENSIONS OF IBUPROFEN

The objective of this study was to develop and evaluate suspensions of ibuprofen-loaded microspheres. The microspheres were prepared with cellulose acetate butyrate (CAB) and cellulose propionate (low molecular weight) (CPL) polymers with 1:2 and 1:3 drug loadings, respectively. To ensure minimum drug release from the microspheres into the suspension, the pH was buffered at 3.5. 0.5% w/v methylcellulose served as the suspending agent. Redispersibility and content uniformity studies carried out during a period of 6 months produced no evidence of a non-dispersible sediment and allowed for a uniform dose withdrawal. The suspensions were able to produce sustained ibuprofen blood levels and decrease gastrointestinal mucosal injury as compared to the free ibuprofen suspension. The suspension of CAB microspheres sustained ibuprofen blood levels for the longest time and produced least gastrointestinal mucosal damage.