title: A simple and sensitive liquid chromatography method for the determination of low dihydrocodeine concentrations in human plasma: its application in Chinese healthy volunteers.
abstract: A simple, sensitive and modified method was developed for determination of low dihydrocodeine (CAS 125-28-0) concentrations in human plasma by high performance-liquid chromatography (HPLC) with diode array detector. Measurement was performed on a Zorbax XDB-C18 analytical column together with a XDB-C18 precolumn at 40 degrees C after a simple one-step extraction. An isocratic mobile phase consisting of acetonitrile-0.1% trifluoroacetic acid (TFA)-water (12:40:48, v/v/v), was run at a flow rate of 1.0 mL/min. Good chromatographic separation was achieved in less than 6.2 min. This assay was linear over a concentration range of 2.50-100 ng/mL with a lower limit of quantification at 2.50 ng/mL. The intra- and inter-day precision (relative standard deviation) was less than 6.00 and 6.62%, respectively, at all concentration levels studied, while the intra- and inter-day accuracy was 1.50-3.73% and -1.35-1.92%, respectively. Recoveries were 76.10-83.81% with coefficients of variation of 1.86-6.93%. Stability of dihydrocodeine in plasma proved to be good. The validated method was successfully applied to a bioequivalence study of dihydrocodeine after a single oral administration of 20 mg dihydrocodeine tartrate in Chinese healthy male volunteers.
authors: Institute of Clinical Pharmacology, Tongji Medical College of Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China.
authors: Wei
authors: W
authors: Tang
authors: Xinxia
authors: X
authors: Liu
authors: Xiangjun
authors: X
authors: Qiu
authors: Shiying
authors: S
authors: Yuan
authors: Jing
authors: J
authors: Wang
authors: Hui
authors: H
authors: Chen
mesh_terms: D000328:Adult; D000701:Analgesics, Opioid / Q000097:blood* / Q000493:pharmacokinetics; D019540:Area Under Curve; D002138:Calibration; D002851:Chromatography, High Pressure Liquid; D003061:Codeine / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics; D004305:Dose-Response Relationship, Drug; D006207:Half-Life; D006801:Humans; D008297:Male; D011786:Quality Control; D012015:Reference Standards; D015203:Reproducibility of Results; D013810:Therapeutic Equivalency; D014292:Trimetazidine / Q000097:blood / Q000493:pharmacokinetics
chemical_list: D000701:Analgesics, Opioid; D014292:Trimetazidine; C014481:dihydrocodeine; D003061:Codeine