Microcomposites theophylline/hydrogenated palm oil from a PGSS process for controlled drug delivery systems

New controlled-release carriers of theophylline prepared with hydrogenated palm oil (HPO) were obtained by Particles from gas saturated solutions (PGSS) at different working pressures. Pressure had no significant effect on the mean diameter of the particles (of about 3.0 μm). However, spherical morphology with a regular surface was preferentially obtained at higher expansion pressures. HPLC analysis revealed a low theophylline encapsulation in the HPO matrix and showed that considerable amounts of theophylline were located at the particles’ surface. Dissolution studies showed that theophylline released from the HPO matrix follows Higuchiʹs model for simple diffusional processes. However, successful correlation with experiment was achieved only with the Brophy and Deasy long-time correction to the Higuchi equation.