Comparative anti-inflammatory potential of crystalline and amorphous nano curcumin in topical drug delivery

Abstract

The problem of poor bioavailability and clinical efficacy of curcumin can be sorted out after converting crystalline Curcumin (CrysCur) into amorphous NanoCurcumin (NanoCur). Amorphous NanoCur was prepared by converting into nanoemulsion (o/w) using water titration method. The formulation were pre-screen by different physical stress tests, followed by in vitro release study, zeta potential, viscosity, transmittance, globule size distribution and ex vivo studies. The morphology of the NanoCur was determined using transmission electron microscopy (TEM) which revealed fairly spherical shape and good correlation with droplet size distribution study. The NanoCur was converted to gel using Cabopol 934. The composition of optimized NanoCur was curcumin (0.154% w/w), Carbopol 934 (0.702% w/w), ethanolic oil phase [ethanol (0.013% w/w): Capryol 90 (0.015%w/w)], Tween 20 (0.076%w/w) as surfactant, PEG 200 (0.038%w/w) as a co-surfactant and distilled water (q.s) as hydration phase. The steady state flux (Jss), permeability coefficient (Kp) and enhancement ratio (Er) of NanoCur gel was determined and compared with CrysCur gel. Anti-inflammatory effects of the formulations were evaluated in carrageenan-induced paw edema method in rats using Diclofenac as a reference. These ant-inflammatory effects of NanoCur was highly significant (p<0.001) compared to CrysCur and significantly (p<0.05) comparable with standard Diclofenac. The histology of the formulation treated skin showed insignificant changes in the integrity except in the group treated with NanoCur. The slight disruption in the integrity of skin may be because of surfactant present in the nano formulations. Short term storage stability showed insignificant changes in the droplet size and zeta potential, proving its high shelf-life. Finally, it was concluded that NanoCur could be a promising tool in the management of topical inflammation.