Nanoemulsion as a carrier for topical delivery of aceclofenac

Abstract

The aim of the present study was to investigate the potential of a nanoemulsion formulated by excipients, selected for their emulsification ability rather than their solubilising ability of drug, for transdermal delivery of aceclofenac. The oil in water nanoemulsions was prepared by screening the excipients and by identifying nanoemulsion area after constructing pseudoternary phase diagram with the help of the selected excipients. The prepared nanoemulsions were subjected to different thermodynamic stability tests. The nanoemulsion formulations that passed thermodynamic stability tests were characterized for viscosity, droplet size, transmission electron microscopy and refractive index. In vitro release rate and permeation rate of aceclofenac nanoemulsion were determined. The in vitro release profile of optimized formulations (NE31) was compared with that of nanoemulsion gel (NG31) and marketed aceclofenac gel (HIG). In vivo anti-inflammatory efficacy study was also carried out for NE31, NG31 and HIG. Transmission Electron Microscopy (TEM) of the passed samples was carried out, which correlated with the particle sizes (390.48 nm) observed. A significant increase in release rate was observed in optimized nanoemulsion formulation NE31 (23.85% Cremophor EL, 7.95% PEG400, 13.6% Triacetin). An increase in permeability parameters such as steady state flux (Jss), permeability coefficient (Kp) and enhancement ratio (Er) was observed in optimized nanoemulsion formulation NE31. On the basis of these parameters NE31was selected for in vivo studies, which in turn revealed a significant increase in anti-inflammatory effects as compared with marketed aceclofenac gel. The anti-inflammatory effects of formulation NE31 showed a significant increase in percent inhibition value when compared with control, this difference was found to be highly significant (p < 0.001). These results suggested that the aim to formulate a nanoemulsion by choosing the excipients on the basis of their emulsification capabilities was proved to have been accomplished.