Gastroresistant microcapsules: new approaches for site-specific delivery of ketoprofen

Ketoprofen is a potent nonsteroidal anti-inflammatory drug (NSAID) that has been widely used in the treatment of rheumatoid arthritis and other related conditions. However, it carry the risk of undesirable systemic side effects and gastrointestinal irritation at the usual dose of oral administration. The aim of this study was to prepare and evaluate gastroresistant microcapsules containing ketoprofen. Microcapsules were obtained by a spray-drying process starting from a O/A emulsion in presence of different pH-dependent materials (Eudragit® L100, Eudragit® S100 and stearic acid) dissolved in the external phase. The influence of formulation factors (oily phase employed for drug solubilisation, type of coating) on the morphology, particle size distribution, drug loading capacity, in-vitro release and ex-vivo permeation characteristics were investigated. Drug loading capacity was very high for all the microcapsules prepared. Formulation factors did not significatively influence the mean particle size, but modified microcapsule in-vitro and ex-vivo behaviour.