title: Development and application of a high-performance liquid chromatography-mass spectrometry method to determine alendronate in human urine.
abstract: Despite the high potential offered by electrospray ionization on highly polar compounds like biphosphonates, few applications have been developed. High-performance liquid chromatography (HPLC) separation methods suitable for such molecules cannot be used in tandem with mass spectrometry (MS) due to high non-volatile salt content; at the same time the sample preparation, in biological fluids, is also a challenging problem. In the past ion-pair chromatography was mainly used in the case of HPLC-MS of biphosphonates, but no application to quantitative pharmacokinetic (PK) studies has been presented. In this study, after preliminary tests with ion-pair chromatography showing a poor sensitivity, a combined derivatization of the amino group and the biphosphonate has been developed and tested in a PK study. Using this analytical approach we were able to fully validate the quantitation of alendronate in the range of 6.667-4860.0 ng/ml in urine (sample volume 2.0 ml); each analytical run was 5.0 min long. The sensitivity achieved permitted a correct evaluation of the alendronate urinary excretion over the full period of urine collection. Sample preparation despite its complexity permitted to process and analyze up to 200 samples in a working day.
authors.affiliation: Pharma Serv International SRL, 52 Sabinelor Street, 5th District, 050853 Bucharest, Romania. isabelat@pharmaserv.ro
authors.forename: Isabela
authors.initials: I
authors.lastname: Tarcomnicu
authors.forename: Luigi
authors.initials: L
authors.lastname: Silvestro
authors.forename: Simona Rizea
authors.initials: SR
authors.lastname: Savu
authors.forename: Adriana
authors.initials: A
authors.lastname: Gherase
authors.forename: Constanta
authors.initials: C
authors.lastname: Dulea
mesh_terms: D019386:Alendronate / Q000031:analogs & derivatives / Q000737:chemistry / Q000493:pharmacokinetics / Q000652:urine*; D001682:Biological Availability; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004002:Clodronic Acid / Q000737:chemistry / Q000652:urine; D004164:Diphosphonates / Q000737:chemistry / Q000652:urine; D012968:Etidronic Acid / Q000737:chemistry / Q000652:urine; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods*; D000077268:Pamidronate; D012015:Reference Standards
chemical_list: D004164:Diphosphonates; D004002:Clodronic Acid; D012968:Etidronic Acid; D000077268:Pamidronate; D019386:Alendronate