Lipid vesicular systems: Formulation optimization and ex vivo comparative study

Abstract

Lornoxicam, is a poorly water soluble non-steroidal anti-inflammatory drug, it provides effective analgesia in patients with acute and sever pain and after surgery. In this study, the effect of formulation ingredients composition and process on the physical properties, in vitro release and ex vivo permeation of lornoxicam traditional and elastic liposomes was investigated. A three-factor, two-level Box–Behnken design was used for optimizing two main ingredients and one process variable in lornoxicam liposomal formulations. The factors were cholesterol quantities, Tween 80 percentages and sonication time. The investigated responses were liposomes particle size and lornoxicam entrapment efficiency percentage. The results in this study revealed that sonication time has the main effect in determining both particle size and entrapment efficiency of liposomal formulations. After evaluating the main and interaction effects of experimental variables on the responses, an optimized formulation was theoretically obtained from Box–Behnken design that has the smallest particle size as well as the highest entrapment efficiency percent when cholesterol quantities, Tween 80 percentage and sonication time were 7.74mg, 2.5% and 3.7min respectively. A novel ex vivo comparison was conducted between lornoxicam traditional liposomes, elastic liposomes and the optimized formulation which generated from Box–Behnken design. The ex vivo results clearly showed that both elastic and optimized formulations have the ability to enhance lornoxicam permeation through rabbit skin over traditional liposomes.