Nanovesicular Delivery of Repaglinide Through Skin

The purpose of the present study was to develop and optimize once a day transdermal transfersomal gel formulation of repaglinide. Repaglinide transfersomal formulations were successfully prepared by conventional rotary evaporation sonication method using 3-factor, 3-level Box-Behnken design (Version 8.0.7.1). Three independent variables used were phospholipon 85G, sodium cholate and sonication time and the dependent variable were vesicle size, % entrapment efficiency and flux. The optimized repaglinide transfersomal formulation yielded significantly higher flux value i.e., 31.14 +/- 1.056 mu g/cm(2)/h over rigid liposomal formulation (1.161 +/- 0.562 mu g/cm(2)/h) with enhancement ratio of 26.82 through rat skin. CLSM studies showed the skin penetration depth nearly seven times more than that of liposomes. The optimized transfersomal formulation was converted into transfersomal gel and was evaluated for parameters such as homogeneity, extrudability, viscosity, pH and spreadability. In-vitro permeation of gel through rat skin provided high flux sufficient to deliver repaglinide to therapeutic concentration into the biological system. The longer t(1/2) of RTGF as compared to oral repaglinide suspension indicated the prolonged release properties of RTGF formulation.