title: Simultaneous determination of p-aminobenzoic acid and its metabolites in the urine of volunteers, treated with p-aminobenzoic acid sunscreen formulation.
abstract: p-Aminobenzoic acid (PABA) and its metabolites (p-aminohippuric acid, p-acetamidobenzoic acid, and p-acetamidohippuric acid) were detected using high-performance liquid chromatography with an electrochemical (carbon paste) detector (HPLC-ECD). For direct current (dc) mode, with the current at a constant potential, and measurements with suitable experimental parameters, a linear concentration from 0.125 to 1.80 microg/ml was found. The detection limit was approximately 2.0 ng/ml. A carbon paste coulometric detector was used to demonstrate that PABA and its metabolites are electrochemically oxidized in acidic media, and to determine, by analyzing human urine, the percutaneous absorption of PABA and its metabolites. Findings using HPLC-ECD and HPLC with an ultraviolet detector (HPLC-UV) were comparable.
authors.affiliation: Department of Applied Chemistry, Chia Nan University of Pharmacy and Science, Tainan 71743, Taiwan. e201466.wang@msa.hinet.net
authors.forename: Lai-Hao
authors.initials: LH
authors.lastname: Wang
authors.forename: Wen-Shiuan
authors.initials: WS
authors.lastname: Huang
authors.forename: Huo-Mu
authors.initials: HM
authors.lastname: Tai
mesh_terms: D010129:4-Aminobenzoic Acid / Q000493:pharmacokinetics / Q000652:urine*; D000328:Adult; D000618:Aminohippuric Acids / Q000652:urine*; D001711:Biotransformation; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D013473:Sunscreening Agents / Q000493:pharmacokinetics*; D010130:p-Aminohippuric Acid / Q000652:urine*; D062366:para-Aminobenzoates
chemical_list: D000618:Aminohippuric Acids; D013473:Sunscreening Agents; D062366:para-Aminobenzoates; C023730:Acedoben; C024893:4-acetylaminohippuric acid; D010129:4-Aminobenzoic Acid; D010130:p-Aminohippuric Acid