Proniosomal Gel for Transdermal Delivery of Lornoxicam: Optimization Using Factorial Design and in Vivo Evaluation in Rats

Abstract

Objective Clinical utility of lornoxicam in oral therapy is primarily restricted by the low solubility and gastric adverse effects. This study evaluated the prospective of optimized proniosomal gel to improve the clinical efficacy of lornoxicam and compare with oral therapy. Methods Proniosomes were formulated by coacervation phase separation technique using span 60, lecithin and cholesterol. A four-factor three-level Box-Behnken design was used to evaluate the effect of amount of four independent variables; span 60 (X1), cholesterol (X2), lecithin (X3) and lornoxicam (X4) on response variables; vesicle size (Y1), entrapment efficiency (Y2) and transdermal flux (Y3). The selected proniosomal gel (F19) was characterized, and evaluated for the transdermal efficacy by ex vivo and in vivo experiments. Results Optimization study signifies that amount of formulation components (span 60, cholesterol, lecithin and lornoxicam) influence the vesicle size, entrapment efficiency and/or transdermal flux. Optimized formulation F19 exhibited nano size with high entrapment efficiency, adequate zeta potential, greater transdermal flux and better stability (at refrigerated conditions). The entrapment of lornoxicam in the bilayers of proniosome vesicles was confirmed by differential scanning calorimeter. Release profile of F19 was distinct (p < 0.001) from gel prepared using hydroxypropyl methylcellulose (control) and displayed steady lornoxicam release by Fickian diffusion. Transdermal administration of F19 significantly inhibited the carrageenan induced hind paw edema in rats as compared to oral lornoxicam group. Conclusions The data observed in this study demonstrated that the developed proniosomal gel (F19) improved the clinical efficacy of lornoxicam as compared to oral therapy.