Anita G. Sullad, Lata S. Manjeshwar, Tejraj M. Aminabhavi and Praveen N. Naik
Interpenetrating network (IPN) blend microspheres of poly(vinyl alcohol) (PVA) and methyl cellulose (MC) were prepared to study their controlled release (CR) characteristics of two drugs viz., watersoluble losartan potassium (LK) and water-insoluble clopidogrel bisulphate (CB) that belong to the class of antihypertensive drugs. Microspheres (dia = 1 μm) were prepared by emulsion crosslinking method using glutaraldehyde as the crosslinking agent. Drug-loaded formulations were characterized by Fourier transform infrared (FTIR) spectroscopy to investigate the chemical interactions of drugs with the IPN matrix. The X-ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and universal testing machine (UTM) were employed to characterize the developed formulations. Equilibrium swelling of the matrices was performed in pH 7.4 buffer media, while the in vitro release was performed in both pH 1.2 and 7.4 buffer media to understand the release profiles of the drugs in simulated stomach as well as intestinal conditions, respectively. The in vitro release data were analyzed using empirical equations to understand the mode of transport.
