________________________________________ Available online at www.sadgurupublications.com * Author for correspondence; E-mail: abdulhasan@hotmail.com; Mo.: 9443475400 Sci. Revs. Chem. Commun.: 1(1), 2011, 7-17 FORMULATION AND EVALUATION OF TOPICAL DRUG DELIVERY SYSTEM CONTAINING CLOBETASOL PROPIONATE NIOSOMES M. ABRAHAM LINGAN, A. ABDUL HASAN SATHALI * , M. R. VIJAYA KUMAR and A. GOKILA Dept. of Pharmaceutics, College of Pharmacy, Madurai Medical College, MADURAI – 625020 (T.N.) INDIA (Received : 04.10.2011, Accepted : 16.10.2011) ABSTRACT The aim of the present study was to formulate topical gel containing clobetasol propionate niosomes to prolong the duration of action and prevent its side effects. The clobetasol propionate niosomes were prepared by altering the ratios between various non-ionic surfactants (Span 40, 60, 80) and cholesterol by three methods such as thin film hydration method, ether injection method and hand shaking method. The prepared niosomes were subjected to drug content analysis, entrapment efficiency, size analysis and invitro drug release studies. The higher entrapment efficiency (91.37%) was obtained with Span 60 niosomes (ratio of surfactant, cholesterol- 1 : 0.5) prepared by thin film hydration method was evaluated for its stability and formulated as gel formulation. The prepared niosomal gel (G2) and marketed gel (G3) were subjected to drug content analysis, in vitro drug release studies and in vivo pharmacodynamic studies. Our results suggested that the niosomal delivery of clobetasol propionate in carbopol gel base acts as a suitable topical drug delivery system to prolong the duration of action. Key words: Clobetasol propionate, Niosomes, Invitro, Carbopol, Invivo, Pharmacodynamic. INTRODUCTION Controlled drug delivery systems are the dosage forms which are developed to achieve better patient compliance, modified drug release, delivery of drug at the site of action, more efficient administration of drugs by various routes and for better therapeutic effect 1 . Niosomes are concentric bilayered vesicles in which an aqueous volume is entirely enclosed by a membranous lipid bilayer mainly composed of non-ionic surfactants and cholesterol. Niosomes can be used to deliver both hydrophobic and hydrophilic drugs via transdermal route. Although niosomes were tried for various routes, it is used in the market for transdermal route (Novasome Products Such as 30% Petrolatum Novasomes and 10% salicyclic acid novasomes). Studies showed that an enhanced delivery of drugs was observed when niosomes was encapsulated. Niosomes increase skin penetration of drugs and it can act as local depot for sustained release of dermally active compounds. Glucocorticosteroids are used topically for a large variety of dermatological conditions 2 . They benefit by virtue of their anti-inflammatory, immune suppressive, vasoconstrictor and antiproliferative