Influence of polymer blends on the characterization of gliclazide--encapsulated into poly (ε-caprolactone) microparticles.

Gliclazide (GLZ)-loaded microparticles made with a polymeric blend were prepared by a solvent evaporation technique. Organic solutions of two polymers, poly(ε-caprolactone) (PCL) and Eudragit RS (E RS) or ethyl cellulose (EC), in different weight ratios, and 33.3% of GLZ were prepared and dropped into aqueous solution of poly vinyl alcohol, in different experimental conditions, achieving drug-loaded microparticles. The obtained microparticles were characterized in terms of yield of production, shape, size, surface properties, drug content, and in vitro drug release behavior. The physical state of the drugs and the polymer was determined by scanning electron microscopy (SEM), Fourier transform infra red and differential scanning calorimetry. Following the in vitro release studies microparticles made from blends of polymer, PCL/E RS or EC showed slower drug release than microparticles made from single PCL polymer. Surface morphology also revealed presence of porous and spherical structure of microparticles. Microparticles showing sustained release of GLZ were examined in rabbits and plasma GLZ concentrations were calculated using HPLC method of assay.