title: Bioavailability study of berberine and the enhancing effects of TPGS on intestinal absorption in rats.
abstract: Berberine chloride (BBR) is a natural isoquinoline alkaloid extracted from medicinal herbs. It has been reported that the intestinal absorption of BBR is very low. In this study, the absolute bioavailability of BBR was studied, and the enhancing effects of D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) on intestinal absorption were investigated in rats. BBR injection was administrated via the femoral vein at a dose of 1.0 mg kg(-1) in intravenous group, and BBR oral formulations were administrated by oral gavage at a dose of 100 mg kg(-1) in BBR control (control) group and BBR-TPGS (test) group, respectively. The result showed that BBR had a very low absolute bioavailability of 0.68%, and TPGS could enhance intestinal absorption of BBR significantly. TPGS at a concentration of 2.5% could improve peak concentration (C(max)) and area under the curve (AUC(0-36)) of BBR by 2.9 and 1.9 times, respectively. The absorption enhancing ability of TPGS may be due to its ability to affect the biological activity of P-glycoprotein and thereby reduce the excretion of absorbed BBR into the intestinal lumen. This study indicated that absolute bioavailability of BBR was 0.68% in rats, and TPGS was a good absorption enhancer capable of enhancing intestinal absorption of BBR significantly.
authors.affiliation: Department of Pharmaceutics, School of Pharmacy, Shenyang Pharmaceutical University, Liaoning Province, People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.forename: Yu-Qiang
authors.initials: YQ
authors.lastname: Miao
authors.forename: Dong-Jiao
authors.initials: DJ
authors.lastname: Fan
authors.forename: Shen-Shen
authors.initials: SS
authors.lastname: Yang
authors.forename: Xia
authors.initials: X
authors.lastname: Lin
authors.forename: Ling-Kuo
authors.initials: LK
authors.lastname: Meng
authors.forename: Xing
authors.initials: X
authors.lastname: Tang
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001599:Berberine / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000592:standards; D001682:Biological Availability; D004337:Drug Carriers / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000592:standards; D004357:Drug Synergism; D007408:Intestinal Absorption / Q000187:drug effects / Q000502:physiology*; D008297:Male; D011092:Polyethylene Glycols / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000592:standards; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D014810:Vitamin E / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000493:pharmacokinetics / Q000592:standards
chemical_list: D004337:Drug Carriers; D001599:Berberine; D014810:Vitamin E; D011092:Polyethylene Glycols; C014225:tocophersolan