The effect of water soluble and insoluble plasticizers on the physicomechanical properties of Eudragit RS 100, RSPM and S 100 was investigated. The plasticizing efficiency was evaluated by measuring the mechanical properties e.g. modulus of elasticity, tensile strength and percent of elongation of the polymeric films. The results showed that the plasticizer effect was dependent on hydrophilicity and chemical structure of both the plasticizers and polymers. The interaction of plasticizers with the polymers was also concentration dependent. The efficiency of pasticizers could be arranged in the following order: glycerol triacetate > glycerol> propylene glycol > polyethylene glycol 400 > dimethylphthalate > diethylphathalate. Also, the moisture absorption capacity was considerably increased by plasticizers in the following order: glycerol> glycerol triactate> polyethylene glycol 400 > propylene glycol> dimethylphthalate > Diehtylphthatlate. The release profile of chlorphenesin was also significantly increased by the polyol plasticizers rather than the organic esters. Moreover, the drug release pattern was found to be following Higuchi diffusion model.