Effect of green tea extract loaded chitosan microparticles on facial skin: A split‐face, double‐blind, randomized placebo‐controlled study

The bioactivities of green tea extract were indicated to promote skin health in vitro. Few clinical studies reported on skin nourishment of topical applying green tea extract due to the limited skin absorption.This current study evaluated the clinical effectiveness and safety of green tea extract encapsulated chitosan microparticles (GTP) in emulsion base on a split-face, double-blind, randomized placebo-controlled study. Twenty-nine female volunteers were recruited into the study. They were randomly assigned to apply GTP and placebo creams on each half face for 8 weeks. The facial skin properties on both sides were monitored and evaluated every 2 weeks.The results revealed that skin elasticity (R2) of half face treated with GTP cream (0.748 ± 0.05) was superior to another that received placebo cream (0.722 ± 0.05) at 4th week. In addition, melanin index implying skin dullness of the half face that received GTP cream significantly improved within the 6th week after application (placebo =295.60 ± 58.81, GTP =282.70 ± 59.62). Most importantly, the photographs clearly indicated that the decreasing in facial wrinkles of volunteers applied with GTP cream was more than those applying placebo cream. Signs of skin irritation were not evident in both treatment and placebo cream groups.Based on study outcomes, the green tea extract encapsulated chitosan microparticles appear to be the promising active candidate for promoting skin elasticity and improving skin dullness and wrinkles.