Preparation and characterization of acrylic copolymer microspheres for the oral controlled release of lipophilic quinidine

Acrylic microparticles were obtained by suspension radical copolymerization of methacrylic acid, methyl methacrylate and ethylene glycol dimethacrylate as the cross-linking agent. The microparticles produced were perfectly spherical, with a relatively narrow size distribution. Microspheres were characterized by yield, exchange capacity, solvent regain, degree of swelling and scanning electron microscopy. Quinidine, a lipophilic drug, was incorporated in acrylic copolymer microspheres during or after the copolymerization process. The amount of entrapped drug and its release were studied in microparticles with different dimensional, morphological and physicochemical properties as function of the experimental parameters employed for their production.