Role of polymer/polymer and polymer/drug specific interactions in drug delivery systems

Abstract

Abstract Drug delivery systems based upon the blending of Arabic gum and poly(N-vinylpyrrolidone) (AG/PVP) were prepared for the controlled release of acebutolol (Acb) hydrochloride. The prepared blends containing Acb were characterized using different techniques. The presence of physical interactions between the drug and polymer matrices was observed with Fourier-transform infrared spectroscopy. These interactions resulted in the transition of the drug from a crystalline to an amorphous state into the polymeric matrices, as demonstrated by differential scanning calorimetry and X-ray diffraction analysis. The thermogravimetric analysis study confirmed the presence of these interactions, which had a stabilizing effect on the drug against both thermal degradation and crystallinity. The in vitro release of Acb from the AG/PVP polymer system was investigated. Each drug-loaded system was used in a tablet formulation. Moreover, an in vitro dissolution study was carried out in three different dissolution media, and comparison of the dissolution profiles of the different dosage forms revealed that the polymer blend matrix had a better release-retarding efficiency. To better understand the release mechanism, the dissolution data were fitted to various release kinetic models.