Objective: Ganciclovir (GCV), a 2'-deoxyguanosine analog, is the most widely used antiviral drug against human cytomegalovirus (HCMV) infections. It has an extremely short half life (2-4 h) and low bioavailability (5-7%) due to first-pass metabolism which favors the development of IPN based drug delivery system. Methods: Novel interpenetrating polymer network (IPN) of xanthan gum (XG) and poly vinyl alcohol (PVA) was prepared by emulsion cross-linking method to deliver model anti-viral drug, ganciclovir, cross-linked with glutaraldehyde (GA) to form microspheres. Various formulations were prepared by changing the ratio of XG: PVA, extent of cross-linking in order to optimize the formulation variables on drug encapsulation efficiency and release rate. FTIR spectroscopy was done to confirm the formation of IPN matrix and the chemical stability of ganciclovir after penetration of microspheres. Results: Microspheres formed were spherical with smooth surfaces as revealed by SEM. IPN formulation F9 composed of XG: PVA (1:4) and glutaraldehyde (5.5 ml) gave the most advantageous entrapment (83.66±2.57%) and release results after 8 hrs (Q8h=54.00±0.61%) in 0.1N HCl, pH 1.2 as compared to other compositions. These results suggest that the IPN microspheres are promising carriers for the controlled delivery of ganciclovir.