title: Preparation of a ligustrazine ethosome patch and its evaluation in vitro and in vivo.
abstract: BACKGROUND
  The purpose of this study was to develop a transdermal ligustrazine patch containing a stable formulation and with good entrapment efficiency, release rate, and transdermal absorption.
  
  
  METHODS
  Ligustrazine ethosomes were prepared by ethanol injection-sonication, with entrapment efficiency as an indicator. Using acrylic resin as the primary constituent, the ligustrazine ethosome patch was prepared by adding succinic acid as a crosslinking agent and triethyl citrate as a plasticizer. In vitro release and transdermal permeation studies were carried out. Finally, a pharmacokinetic study was carried out in rats to explore relative bioavailability. The formulations of ligustrazine ethosome were 1% (w/v) phospholipid, 0.4% (w/v) cholesterol, and 45% (v/v) ethanol.
  
  
  RESULTS
  Ligustrazine ethosomes were obtained with an average particle size of 78.71 ± 1.23 nm and an average entrapment efficiency of 86.42% ± 1.50%. In vitro transdermal testing of the ligustrazine ethosome patches showed that the cumulative 24-hour amount of ligustrazine was up to 183 ± 18 μg/cm(2). The pharmacokinetic results revealed that the relative bioavailability was 209.45%.
  
  
  CONCLUSIONS
  Compared with conventional ligustrazine administration, ligustrazine ethosome patches could promote better drug absorption and increase bioavailability. This study demonstrates that the transdermal action of the ligustrazine ethosome patch was comparatively good.
authors.affiliation: China-America Cancer Research Institute, Guangdong Medical College, Dongguan, Guangdong, People's Republic of China.
authors.forename: Xingyan
authors.initials: X
authors.lastname: Liu
authors.forename: Hong
authors.initials: H
authors.lastname: Liu
authors.forename: Jianqiang
authors.initials: J
authors.lastname: Liu
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: He
authors.forename: Congcong
authors.initials: C
authors.lastname: Ding
authors.forename: Guoliang
authors.initials: G
authors.lastname: Huang
authors.forename: Weihua
authors.initials: W
authors.lastname: Zhou
authors.forename: Leshan
authors.initials: L
authors.lastname: Zhou
mesh_terms: D000818:Animals; D001682:Biological Availability; D003692:Delayed-Action Preparations / Q000008:administration & dosage / Q000493:pharmacokinetics; D006801:Humans; D008081:Liposomes / Q000008:administration & dosage / Q000737:chemistry; D008297:Male; D050997:Nanomedicine; D010316:Particle Size; D011719:Pyrazines / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D057968:Transdermal Patch; D014665:Vasodilator Agents / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics
chemical_list: D003692:Delayed-Action Preparations; D008081:Liposomes; D011719:Pyrazines; D014665:Vasodilator Agents; C017953:tetramethylpyrazine