title: Determination of calcium dobesilate in human plasma using ion-pairing extraction and high-performance liquid chromatography.
abstract: A rapid, simple reversed-phase high-performance liquid chromatographic method with ultraviolet absorbance detection has been developed for the determination of calcium dobesilate in human plasma. Sample processing is based on an ion-pairing extraction with tetra-n-butylammonium hydroxide as cationic pairing ion and dichloromethane. Separation of the investigated calcium dobesilate and 2,4-dihydroxybenzoic acid as internal standard was achieved on a Discovery RP-Amide C16 analytical column with 50 mM, pH 2.5, potassium dihydrogenphosphate buffer-acetonitrile (75:25, v/v) mobile phase. The wavelength was set at 305 nm. The limit of quantitation is 100 ng/ml and the calibration curve is linear up to 50 microg/ml. Within-day and between-day precision expressed as the relative standard deviation is about 10% and the accuracy of the determination did not deviate from 100% by more than +/-10%. The developed method was found to be suitable for application in human bioequivalence studies.
authors.affiliation: Department of Internal Medicine, Faculty of Health Sciences, Semmelweis University, Budapest, Hungary. rona@hiete.hu
authors.forename: K
authors.initials: K
authors.lastname: Róna
authors.forename: K
authors.initials: K
authors.lastname: Ary
mesh_terms: D002123:Calcium Dobesilate / Q000097:blood* / Q000737:chemistry / Q000302:isolation & purification / Q000493:pharmacokinetics; D002851:Chromatography, High Pressure Liquid / Q000379:methods / Q000592:standards; D004355:Drug Stability; D006801:Humans; D062385:Hydroxybenzoates / Q000592:standards; D015394:Molecular Structure; D015203:Reproducibility of Results; D013810:Therapeutic Equivalency
chemical_list: D062385:Hydroxybenzoates; D002123:Calcium Dobesilate; C017704:beta-resorcylic acid