title: Simple, economical, and reproducible LC-MS method for the determination of amoxicillin in human plasma and its application to a pharmacokinetic study.
abstract: A simple, economical, and reproducible high-performance liquid chromatography mass spectrometric (MS) method is developed and validated for the determination of amoxicillin in human plasma. The present method has been successfully used to determine bioequivalence between a test and innovator formulation of amoxicillin 500 mg capsules. The method is validated in terms of selectivity, precision/accuracy, recovery, dilution integrity, matrix effect, effect of anti-coagulant, and stability studies. Sample preparation is carried out by solid-phase extraction (HLB Oasis cartridges). The processed sample is chromatographed on Hypersil Gold (4.6 x 50 mm); 3 microm C18 column, using 10mM ammonium formate buffer (pH 5.0) and acetonitrile, (10:90, v/v) as mobile phase. Amoxicillin is detected by MS-MS detection with turbo-ion spray in positive ion mode. The weighed (1/X2) calibration curves were linear over the range of 0.17 to 17.0 microg/mL. The intra day precision is from 1.3% to 8.8% and intra day accuracy is 94.1% to 108.5%. The inter day precision is from 1.8% to 6.2% and inter-day accuracy is 95.1% to 105.9%. Mean recovery of 66.3% is observed for amoxicillin and 71.6% for internal standard (ampicillin). The stability of amoxicillin is studied at -15 degrees C and -50 degrees C using human plasma with different anti-coagulants (citrate, monobasic sodium phosphate, dextrose, and adenine-citrate, monobasic sodium phosphate, dextrose, and adenine and ethylene diamine tetraacetic acid-ethylene diamine tetraacetic acid). No significant degradation is observed for 60 days.
authors.affiliation: Department CPP, Ranbaxy Research Laboratories, Plot-20, Sec-18, Udyog Vihar Industrial Area, Gurgaon, Haryana, India.
authors.forename: A H
authors.initials: AH
authors.lastname: Khuroo
authors.forename: T
authors.initials: T
authors.lastname: Monif
authors.forename: P R P
authors.initials: PR
authors.lastname: Verma
authors.forename: S
authors.initials: S
authors.lastname: Gurule
mesh_terms: D000658:Amoxicillin / Q000097:blood* / Q000737:chemistry / Q000493:pharmacokinetics; D000900:Anti-Bacterial Agents / Q000097:blood / Q000493:pharmacokinetics; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006801:Humans; D015394:Molecular Structure; D015203:Reproducibility of Results; D052616:Solid Phase Extraction; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D000900:Anti-Bacterial Agents; D000658:Amoxicillin