305ENHANCEMENT OF PERMEABILITY OF LOSARTAN POTASSIUM BY FORMULATING AS PRONIOSOMAL GELNovel drug delivery attempts to either sustain drug action at a predetermined rate or by maintaining a relatively constant, effective drug level in the body with minimization of undesirable side effects. Encapsulation of a drug in vesicular structures can be predicted to prolong the existence of the drug in systemic circulation and perhaps, reduces the toxicity if selective uptake can be achieved. Proniosomes are dry formulation of water-soluble carrier particles that are coated with surfactant and can be measured out as needed and dehydrated to form niosomal dispersion immediately before use on brief agitation in hot aqueous media within minutes. The potential of proniosomes as a transdermal drug delivery system for Losartan potassium was investigated by encapsulating the drug in various formulations of proniosomal gel composed of various ratios of Span (sorbitan esters) and Tween (polyoxythylene sorbitan esters), cholesterol, lecithin prepared by coacervation-phase separation technique. The formulated systems were characterized for Vesicle physical analysis, drug entrapment, rate of spontaneity, FTIR Studies, in vitro release kinetics, drug release profiles, and vesicular stability at different storage conditions for Losartan potassium proniosomal gel were carried out according to ICH Guidelines. The results showed that the type of surfactant incorporated altered the entrapment efficiency of proniosomal gel and higher entrapment efficiency of 98.24% was obtained with the proniosomal gel PNG F4. The average vesicle size was found to be 9 -15µ, FTIR studies revealed that there was no interaction between the drug and excipients. The drug release kinetics revealed that the release pattern was found to be Zero Order.sandhyapasikanti@gmail.comResearch4102013 Losartan potassium,Novel drug delivery,Proniosomal gelSandhya P,Saleha Fatima Mehvash,Subrahmanyam CVS Shadan Womens College of Pharmacy, Khairatabad, Hyderabad, Andhra Pradesh, India.,University College of Technology, Osmania University, Hyderabad, Andhra Pradesh, India.,Department of Pharmaceutics, Gokaraju Rangaraju College of Pharmacy, Hyderabad, Andhra Pradesh, India