Novel interpenetrating polymer network (IPN) of Lepidium sativum (Ls) and poly vinyl alcohol (PVA) were prepared and cross-linked with glutaraldehyde (GA) to form microspheres by emulsion cross-linking method to deliver model drug, simvastatin. In the present study, the seeds of Lepidium sativum were selected for the isolation of mucilage. The work also emphasizes to study the physicochemical characteristics of mucilage from Lepidium sativum seeds. Various formulations were prepared by changing the ratio of Ls:PVA, extent of cross-linking in order to optimize the formulation variables on drug encapsulation efficiency and release rate. Fourier transform infrared (FTIR) spectroscopy was done to confirm the formation of interpenetrating network and the chemical stability of simvastatin after penetration of microspheres. Microspheres formed were spherical with smooth surfaces as revealed by scanning electron microscopy (SEM), and mean particle size as measured by optical microscopy ranged between 20.14±1.11 to 39.73±0.53 μm. Drug encapsulation of up to 86.65% was achieved as measured by UV method. Both equilibrium swelling studies and in-vitro release studies were performed in pH 7.4 media. Release data indicated that a drug release which depends on the extent of cross-linking and the ratio of Ls:PVA present in the microsphere. Based on the results of in-vitro studies it was concluded that these IPN microspheres provided oral controlled release of simvastatin.