Abstract

PREFORMULATION OPTIMIZATION OF CATECHIN EXTRACTS FROM ASSAM GREEN TEA AS A CANDIDATE FOR TOPICAL CHEMOPREVENTION

Manasiwini Bharaduwaj and Malay K. Das*

Abstract

This study reports the solution stability of the main polyphenol component Epigallocatechin Gallate (EGCG) in Assam Green Tea extract to facilitate the further development as topical formulation for cancer chemoprevention. Extraction of green tea was carried out by solvent partitioning method to get maximum amount of water soluble extractives such as EGCG and other catechins. Green tea polyphenols especially EGCG has been reported to be very susceptible to degradation in aqueous medium at room temperature. The stability studies of green tea extract was performed in buffers of different pH, distilled water and methanol to assess the extent of degradation of EGCG with time and the effect of solvent pH on the same. The change in EGCG concentration with time was recorded. An ISO standard simple High Performance Liquid Chromatography (HPLC) method was used to quantify the amount of EGCG in green tea extract. The solution stability of EGCG was found to be prolonged with pH 4.5, which is almost close to pH of the skin. Extract was subjected to freeze drying and kept at 4oC for ease of use in further studies. The extract prepared in pH 4.5 can be successfully used in topical formulation for effective topical chemoprevention.

Keywords: Green Tea Extract, Epigallocatechin Gallate (EGCG), Catechins, Chemoprevention, Skin cancer.