Formulation and Evaluation of Etoricoxib Niosomes by Thin Film Hydration Technique and Ether Injection Method

The main objective of this study is to formulate etoricoxib niosomes as vesicular carriers for site specific drug delivery. Niosomes are novel vesicular carriers, in which the drug is incorporated in a vesicle. Niosomal vesicles are formed by hydrating mixture of cholesterol and nonionic surfactants. Niosomes can increase the permeability of the skin (stratum corneum and epidermis), by avoiding the first pass metabolism and also reduce the side effects. Etoricoxib is a potent new COX-2 inhibitor used in the treatment of osteoarthritis, rheumatoid arthritis, ankylosing spondylitis, acute gout arthritis etc. Two formulations were prepared by thin film hydration technique using the drug, cholesterol and surfactants Tween 80 (F1) and Span 60 (F2). Another two formulations were prepared by ether injection method using cholesterol and surfactants Tween 80 (F3) and Span 60 (F4). Each formulation was evaluated for drug content, entrapment efficiency, mean vesicular diameter, zeta potential and In-vitro drug release studies. Among the four formulations, F2 formulation containing the drug and Span 60 showed maximal drug content of 95.57%, entrapment efficiency of 96.40%, mean vesicular diameter of 463.7 nm, zeta potential of -80.5 mV, in-vitro drug release of 95.14% in 12 h, and the drug release followed the first order with non-fickian diffusion mechanism by thin film hydration technique. Hence, the thin film hydration technique is an optimized technique for the preparation of etoricoxib niosomes.