Enhanced oral delivery of epigallocatechin gallate via expanding gastro-retentive films composed of chitosan and konjac glucomannan blends

Epigallocatechin gallate (EGCG), a bioactive compound extracted from green tea, is known for its antioxidant, anti-inflammatory, and anti-obesity effects. However, it is prone to degradation in the gastrointestinal tract due to the alkaline pH and enzymatic activity in the intestine, leading to reduced therapeutic efficacy. To overcome this limitation, EGCG was incorporated into a chitosan-based expandable film designed for prolonged gastric retention and controlled release. Chitosan, a highly swelling polymer, was combined with konjac glucomannan (KGM) as a secondary polymer, along with sodium alginate and glycerin. This system exhibited significant swelling in simulated gastric fluid (pH 1.2), maintaining its expanded structure and achieving a sustained release of over 80% within 8 hours. The inclusion of KGM enhanced the film’s tensile strength, improving its mechanical properties. Bioactivity studies demonstrated that the EGCG-loaded film significantly inhibited inflammation by reducing nitric oxide production in RAW 264.7 macrophage cells. Additionally, it suppressed lipid accumulation on 3T3-L1 adipocytes, supporting its potential anti-obesity effects. These findings suggest that the chitosan–KGM-based expandable film offers an effective gastro-retentive system for EGCG delivery, ensuring prolonged release and enhanced therapeutic benefits.