title: Determination of rifampicin in rat plasma by modified large-volume direct injection RAM-HPLC and its application to a pharmcokinetic study.
abstract: A direct large volume injection high-performance liquid chromatography (HPLC) method with homemade restricted-access media (RAM) pre-column and combined with a column-switching valve was established and developed for determination rifampicin (RIP) in rat plasma. The rat plasma samples (100 μL) were injected directly onto pre-column, where RIP was retained and pre-concentrated, while proteins were washed to waste using a methanol-water (5:95) as the mobile phase at a flow rate of 1 mL/min. Then, by rotation of the switching valve at 5 min, the RIP were eluted from the pre-column and transferred to an Luna C18 analytical column by the chromatographic mobile phase consisting of methanol-acetonitrile-10 mm ammonium format (60:5:35) at a flow rate of 1 mL/min. The total analytical run time was 15 min with UV detection wavelength at 254 nm. Carbamazepine was used as the internal standard. Excellent linear correlation (r = 0.9993) was obtained in the range of 0.25-8 µg/mL for rat plasma. The intra-day and inter-day precisions of RIP were all <5.0%. The recoveries were in the range of from 99.98-113.66% for plasma. This on-line RAM-HPLC method was successfully applied to the pharmacokinetic study of RIP in rat plasma.
authors.affiliation: PLA Key Laboratory of the Plateau of the Environmental Damage Control, Department of Pharmacy, Lanzhou General Hospital of PLA, Lanzhou, 730050, China; School of Pharmacy, Lanzhou University, Lanzhou, 730000, China.
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Zhang
authors.forename: Rong
authors.initials: R
authors.lastname: Wang
authors.forename: Hua
authors.initials: H
authors.lastname: Xie
authors.forename: Zhengping
authors.initials: Z
authors.lastname: Jia
authors.forename: Wenbing
authors.initials: W
authors.lastname: Li
authors.forename: Juanhong
authors.initials: J
authors.lastname: Zhang
authors.forename: Yanling
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000097:Acetonitriles / Q000737:chemistry; D000284:Administration, Oral; D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods*; D004355:Drug Stability; D008297:Male; D000432:Methanol / Q000737:chemistry; D017208:Rats, Wistar; D015203:Reproducibility of Results; D012293:Rifampin / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics*; D012680:Sensitivity and Specificity
chemical_list: D000097:Acetonitriles; D012293:Rifampin; D000432:Methanol; C032159:acetonitrile
keywords: RAM-HPLC; large volume injection; pharmacokinetic; rat plasma; rifampicin