DESIGN AND DEVELOPMENT OF EMULSION-BASED CLEAR COMPLEXION SKIN WHITENING CREAM USING GLYCYRRHIZA GLABRA (LICORICE) ROOT EXTRACT AND VATERIA INDICA (WHITE DAMMAR) BARK EXTRACT BY SKIN MELANIN INHIBITORY PATHWAY

The objective of this study was to design and develop a skin lighting cream for improved skin whitening using herbal extracts from Glycyrrhiza glabra (Licorice) root and Vateria indica bark. The carrier cream base was developed by emulsion technique to deliver skin whitening property by holding the natural herbal actives such as G. glabra root extract and V. Indica bark extract as well as physical sun protecting agents such as titanium dioxide for the skin whitening properties. The emulsion cream was designed and optimized to deliver the skin lighting property by the combination of G. glabra root extract and V. Indica bark extract. This unique composition helps to provide the melanin inhibition effect through cellular melanin inhibition pathway. The optimized emulsion cream formula was evaluated as per ICH stability guidelines (real time, 30°C and 65% Relative Humidity (RH) and accelerated, 45°C and 75% RH) to ensure emulsion cream stability and shelf life of the product. The optimized and stabilized formula flow behaviours were determined by various rheological studies such as flow curve measurements (viscosity vs. shear rate), amplitude sweep measurement(linear visco elastic range), frequency sweep measurements (stability test), amplitude sweep measurements (spreadability test), and thixotropic test. The performance of the final product was measured by skin melanin inhibition property and the results observed indicated better skin lighting compared with control. The safety of the final product was measured by Netral Red Uptake NRU-assay using NIH3T3 cell lines and the CTC₅₀ value of the product was found to be >1000μg/ml at 24 h study period.