Effect of hydroxypropyl methyl cellulose phthalate coating on digestive stability and intestinal transport of green tea catechins

The purpose of this study was to investigate the effect of hydroxypropyl methyl cellulose phthalate (HPMCP) coating on the digestive stability and intestinal transport of green tea catechins (GTCs). Two types of HPMCP coating were prepared: one type with size smaller than 500μm (S-HPMCP) and the other with size larger than 500μm (L-HPMCP). An in vitro gastrointestinal model system coupled with Caco-2 cells was used for estimating the bioavailability of GTCs. Ultraperformance liquid chromatography with a photodiode array detector was performed to analyze GTCs. The digestive stability of GTCs was enhanced up to 33.73% and 35.28% for S-HPMCP and L-HPMCP, respectively. Intestinal transport of the GTCs was increased to 22.98% and 23.23% for S-HPMCP and L-HPMCP, respectively. Overall, the bioavailability of GTCs increased by 4.08 and 11.71 times for S-HPMCP and L-HPMCP, respectively. The results of this study confirm that coating with HPMCP could be a way to improve the digestive stability and intestinal transport of GTCs.