title: Impacts of bicyclo-monoterpene enhancers on transdermal delivery of ligustrazine.
abstract: The purpose of this study is to investigate the impacts of bicyclo-monoterpene promoters (i.e., borneol and camphor) on the in vitro permeation of ligustrazine (LGT) through the hairless porcine dorsal skin. Fourier transform-infrared (FT-IR), scanning electron microscope (SEM) and transdermal delivery kinetics in vitro were performed to investigate the effect of the promoters on the biophysical changes to the stratum corneum (SC), the surface changes to porcine skin and the in vitro percutaneous fluxes of ligustrazine through procine skin. FT-IR results revealed that the peak shift and the decrease in the peak area with borneol were higher than those with camphor. SEM studies demonstrated that the morphological change to SC was related to the chosen enhancer. It was observed that the SC lipid extraction with borneol and camphor led to disruption of the SC and the scutella desquamation. Apparent density (AD) was utilized to describe the desquamation extent of the scutella. Percutaneous fluxes of ligustrazine through porcine skin were evaluated in vitro by the Franz-type diffusion cells. Use of borneol led to greater penetration of ligustrazine across porcine skin. It was shown that the permeation enhancement mechanism of bicyclo-monoterpenes to ligustrazine included extracting and disordering lipids which involved the shift changes in C-H stretching and H-bonding action between enhancers and cermaide. The penetration capability of the hydroxy groups in bicyclo-monoterpenes was better than that of the ketone groups.
authors.affiliation: School of Chinese Materia Medica, China Pharmaceutical University, Nanjing 211198, China. zhangchunfeng67@163.com
authors.forename: Chun-Feng
authors.initials: CF
authors.lastname: Zhang
authors.forename: Wei
authors.initials: W
authors.lastname: Zhan
authors.forename: Zhong-Lin
authors.initials: ZL
authors.lastname: Yang
authors.forename: Ye-Li
authors.initials: YL
authors.lastname: Wang
mesh_terms: D000279:Administration, Cutaneous; D000818:Animals; D001892:Camphanes / Q000737:chemistry / Q000494:pharmacology; D002164:Camphor / Q000737:chemistry / Q000494:pharmacology; D004337:Drug Carriers; D030004:Ligusticum / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D039821:Monoterpenes / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry; D011719:Pyrazines / Q000008:administration & dosage* / Q000737:chemistry / Q000302:isolation & purification / Q000493:pharmacokinetics*; D012867:Skin / Q000187:drug effects; D012869:Skin Absorption / Q000187:drug effects*; D017550:Spectroscopy, Fourier Transform Infrared; D013552:Swine; D014665:Vasodilator Agents / Q000008:administration & dosage / Q000737:chemistry / Q000302:isolation & purification / Q000493:pharmacokinetics
chemical_list: D001892:Camphanes; D004337:Drug Carriers; D039821:Monoterpenes; D011719:Pyrazines; D014665:Vasodilator Agents; D002164:Camphor; C022871:isoborneol; C017953:tetramethylpyrazine