Green tea extracts largely consist of anti-oxidative/anti-inflammatory catechins such as (-)-epigallocatechin gallate. Orally administered catechins are metabolized in the gastrointestinal tract and liver, subsequently incurring low bioavailability. This study attempts to improve the bioavailability of catechin by using mPEG-PCL-graft-2-hydroxycellulose (mPEG-PCL-g-HEC) porous membrane as a penetration matrix for skin delivery of catechins. The green tea-extracted catechin was obtained based on the partition difference in two phases of solvents. In vitro permeation tests using a Franz diffusion cell system indicated that the mPEG-PCL-g-HEC membrane with a loading content of the catechins of 1.5 mg/cm(2) significantly enhanced the permeation of the catechins up to 0.84 mg/mL in the receptor of Franz cell for a period of 48 h, whereas the permeated catechins through HEC membrane was only 0.04 mg/mL Moreover, a comparative experiment of the oral and transdermal administrations was conducted to measure the delivered catechins in plasma in Wistar rats. In the oral administration where free catechin was given, the catechin AUC was 34.22 +/- 1.51 mu g h/mL and C(max) was 22.7 +/- 1.29 mu g/mL, respectively. Conversely, in the transdermal administration using catechins-loaded E(50)C(36)-g-HEC membranes, the catechin AUC of 356.24 +/- 3.24 mu g h/mL and C(max) of 19.03 +/- 0.75 mu g/mL was obtained. Furthermore, a higher catechin AUC of E(50)C(36)-g-HEC membrane than that of E(50)-C(84)-g-HEC membrane presented a role of the permeation enhancer to the amphiphilic polymer grafted to the cellulosic material. Therefore, this study showed the potential use of amphiphilic polymer mPEG-PCL in controlling the delivery of catechins via skin. (C) 2011 Elsevier B.V. All rights reserved.