Development of (−)-epigallocatechin-3-gallate (EGCG)-loaded enteric microparticles with intestinal mucoadhesive property

Abstract

The main purpose of the present investigation was to develop a novel enteric mucoadhesive formulation of (−)-epigallocatechin-3-gallate (EGCG), a green tea catechin, with the aim of avoiding its severe degradation in the gastrointestinal tract and therefore improving pharmacological effects. The EGCG-loaded microspheres (EGCG/MS), containing Eudragit ® S100, were prepared with an emulsion solvent diffusion method in aqueous PVA solution. The EGCG/MS with a diameter of 16 μm exhibited pH-dependent controlled release of EGCG with limited initial burst release, and the Eudragit ® S100-based MS also had moderate bioadhesive property in isolated small intestine of rats. There appeared to be marked degradation of EGCG in acidic solution (pH 1.2) and neutral buffer (pH 6.8) containing intestinal microsomal fraction, although significant improvement in chemical and metabolic stability of EGCG was observed in the EGCG/MS, possibly due to the controlled release and/or bioadhesion. From these findings, newly prepared EGCG/MS might be of clinical importance in both stabilizing and delivering EGCG for treatment of intestinal diseases.