title: In vitro evaluation of patch formulations for topical delivery of gentisic acid in rats.
abstract: Gentisic acid (GA) is used in cosmetics as a skin-whitening agent for the treatment of skin pigmentary disorders by influencing the synthesis of melanin through inhibition of melanosomal tyrosinase activity. In order to achieve effective topical delivery of GA to the active site in the skin, a matrix-type transdermal delivery system was developed. The in vitro skin permeation as well as skin deposition of GA was studied in rats. Among the five pressure-sensitive adhesives tested, DuroTak 87-2510 was the most effective to achieve the highest permeation rate of GA. Dodecylamine showed the most potent enhancement among the enhancers tested, and significantly increased the permeation rate of GA up to 112.99 (+/-30.12) microg/cm(2) per h at the concentration of 1%, when 6% GA was incorporated in DuroTak 87-2510. Moreover, a linear relationship was observed between the skin permeation rate of GA and the amount of the skin deposition after 12 h of permeation (r(2)=0.95). Thus, the in vitro skin permeation data may be useful to determine the amount of GA actually deposited in the skin.
authors.affiliation: College of Pharmacy, Pusan National University, Pusan 609-735, South Korea.
authors.forename: Shengjie
authors.initials: S
authors.lastname: Bian
authors.forename: Hea-Jeong
authors.initials: HJ
authors.lastname: Doh
authors.forename: Junmin
authors.initials: J
authors.lastname: Zheng
authors.forename: Jung Sun
authors.initials: JS
authors.lastname: Kim
authors.forename: Chi-Ho
authors.initials: CH
authors.lastname: Lee
authors.forename: Dae-Duk
authors.initials: DD
authors.lastname: Kim
mesh_terms: D000287:Administration, Topical; D000818:Animals; D002626:Chemistry, Pharmaceutical; D016503:Drug Delivery Systems / Q000379:methods*; D004353:Drug Evaluation, Preclinical / Q000379:methods; D005841:Gentisates; D062385:Hydroxybenzoates / Q000008:administration & dosage* / Q000737:chemistry; D066298:In Vitro Techniques; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012869:Skin Absorption / Q000187:drug effects* / Q000502:physiology
chemical_list: D005841:Gentisates; D062385:Hydroxybenzoates; C010925:2,5-dihydroxybenzoic acid