Investigating Skin Permeation Behavior, Skin Irritation and Anti-Inflammatory Activity of Diclofenac Diethylamine Novel Formulation Prepared using Shea Butter as Absorption Base with Nerolidol as Permeability Enhancer

Abstract

Background: The present investigation was to study the drug permeation of diclofenac diethylamine (DDEA) cream
prepared using shea butter as the absorption base and nerolidol as a permeability enhancer and also to evaluate skin
irritation and anti-inflammatory study of prepared cream on Wistar rats in comparison with marketed formulation.
Materials and Methods: The cream prepared using shea butter and nerolidol was assessed for permeation study
through rat skin. The three formulations mainly F0 (without nerolidol), F5 (containing 0.5% nerolidol), and the
marketed formulation were assessed for % drug permeation through rat skin along with an estimation of flux and
permeability coefficient. A skin irritation study of a placebo, F0, and F5 formulation was carried out on Wistar rats.
Anti-inflammatory study of transdermal cream formulation of control, placebo, F0, F5, and marketed formulation
was evaluated for anti-inflammatory study on Wistar rat using carrageenan-induced rat paw edema method.
Results: The F5 formulation showed enhanced drug permeation as compared to the F0 and marketed formulation.
The flux value F5 formulation was found to be 0.3942 ± 0.009 g/cm2/min as compared to F0 and marketed formulation
which were found to be 0.2789 ± 0.013 g/cm2/min and 0.2730 ± 0.0110 g m/cm2/min, respectively. The permeability
coefficient for the F5 formulation was found to be 2.370 × 10-5 m/s as compared to F0 and marketed formulations
which were found to be 1.680 × 10-5 and 1.640 × 10-5 m/s, respectively. The F0 and F5 formulations were found to be
non-irritant and no edema was observed on its application. F5 formulation showed significant inhibition of edema
in rat paw volume induced by carrageenan as compared to control, placebo, Std, and F0 batches. Conclusion: The
study demonstrates that the F5 formulation prepared using shea butter as an absorption base and containing 0.5% w/v
of nerolidol as a permeability enhancer showed a better permeation of DDEA through rat skin, non-irritant in nature
and significant anti-inflammatory activity as compared to F0 and marketed formulation.