title: Direct pharmaceutical analysis of bisphosphonates by capillary electrophoresis.
abstract: Bisphosphonate compounds have been studied as a class of potential drugs for the treatment of various bone diseases. However, the analyses of these compounds are problematic because most of them do not contain strong chromophores. Based on the unique structures of these compounds, we have employed a capillary electrophoresis (CE) technique for the characterization of these compounds in pharmaceutical dosage formulations. In this study, two CE methods were developed for the determination of a bisphosphonate compound, 2-thioethane-1,1-bisphosphonic acid. The first method involved the use of an uncoated column, a phosphate buffer, and hydrostatic injection with direct UV absorbance detection. The method showed excellent resolution and precision with a reasonable detection limit of 30 microg/ml. Sensitivity was further improved using a glycerol-coated column, together with a phosphate buffer of higher concentration and electrokinetic injection under sample stacking conditions. This modified method revealed a significant improvement in sensitivity with a detection limit of about 50 ng/ml. Both methods demonstrated high simplicity and excellent reproducibility and were successfully applied to the quantitative analyses of pharmaceutical dosing solutions.
authors.affiliation: The Procter & Gamble Company, Health Care Research Center, Mason, OH 45040, USA.
authors.forename: S X
authors.initials: SX
authors.lastname: Peng
authors.forename: R
authors.initials: R
authors.lastname: Takigiku
authors.forename: D E
authors.initials: DE
authors.lastname: Burton
authors.forename: L L
authors.initials: LL
authors.lastname: Powell
mesh_terms: D002626:Chemistry, Pharmaceutical; D019075:Electrophoresis, Capillary / Q000379:methods*; D009943:Organophosphorus Compounds / Q000032:analysis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: C113765:2-thioethane-1,1-bisphosphonic acid; D009943:Organophosphorus Compounds