title: Pharmacokinetic detection of penicillin excreted in urine using a totally internally reflected resonance light scattering technique with cetyltrimethylammonium bromide.
abstract: A quantitative analysis method for penicillins including ampicillin (AmP), benzyl penicillin (BP), oxacillin (OA) and amoxycillin (AmO) is proposed that makes use of the totally internally reflected resonance light scattering (TIR-RLS) signal from the penicillin at the H2O/CCl4 interface in the presence of cetyltrimethylammonium bromide (CTMAB), and enables the pharmacokinetics of penicillin taken orally and excreted through urine to be monitored. Penicillin is coadsorbed with CTMAB at the H2O/CCl4 interface in neutral solution, resulting in the formation of ion associates that display greatly enhanced TIR-RLS signals (maximum at 368-372 nm). This enhanced TIR-RLS intensity was found to be proportional to the penicillin concentration over the range 0.2 x 10(-6) to 2.2 x 10(-6) mol L(-1), with limits of determination (3sigma) of 5.0 x 10(-8) to 7.0 x 10(-8) mol L(-1). Pharmacokinetics studies performed using the present method show that the excretion of orally-taken ampicillin through urine has a half-time of 1.05 h and an excremental quantum over 8 h of 49.3%, respectively.
authors.affiliation: College of Chemistry and Chemical Engineering, Key Laboratory of Eco-Environments of Three Gorges Reservoir Region, Ministry of Education of PRC, Southwest Normal University, Chongqing, 400715, People's Republic of China. chengzhi@swnu.edu.cn
authors.forename: Cheng Zhi
authors.initials: CZ
authors.lastname: Huang
authors.forename: Ping
authors.initials: P
authors.lastname: Feng
authors.forename: Yuan Fang
authors.initials: YF
authors.lastname: Li
authors.forename: Ke Jun
authors.initials: KJ
authors.lastname: Tan
mesh_terms: D002138:Calibration; D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000737:chemistry*; D006801:Humans; D008027:Light; D010406:Penicillins / Q000493:pharmacokinetics* / Q000652:urine; D012015:Reference Standards; D012542:Scattering, Radiation; D013050:Spectrometry, Fluorescence
chemical_list: D002593:Cetrimonium Compounds; D010406:Penicillins; D000077286:Cetrimonium