Quantification Of Zaltoprofen And Tiopronin In Human Plasma And Applications

1. Quantitative analysis of zaltoprofen in human plasma and urine and its applicationsBackground Zaltoprofen is a non-steroidal anti-inflammatory drug, which was developed by Nippon Chemiphar Co. Ltd. It is widely used for treatment of rheumatic arthritis, osteoarthritis and chronic pain.Objective To develop and validate a specific and sensitive liquid chromatographic-tandem mass spectrometric method for determination of zaltoprofen in human plasma and urine and aplication to pharmacokinetic study.Method Determination of zaltoprofen in human plasma and urine by liquid chromatography-tandem mass spectrometry. The plasma sample or urine sample was extracted with ether, then separated on a Zorbax XDB C18column (150x4.6mm I.D.,5μm) column using methanol-5mmol·L-1ammonium acetate (70:30, v/v) as the mobile phase. A triple quadrupole mass spectrometry equipped with electrospray ionization source (ESI) source was used as the detector and operated in the negative ion mode. Quantitation was performed using seclective reaction monitoring (SRM) of the transitions of m/z297â†'m/z219and m/z480â†'m/z418for zaltoprofen and the internal standard rosuvastatin, respectively.Results The linear concentration range of the calibration curve for zaltoprofen was20.0-8000ng·mL-1, The lower limit of quantification was20.0ng·mL-1. The intra-day and inter-day relative standard deviation over the entire concentration range were less than9.7%. The accuracy was in the range of-4.0%to-0.5%in terms of relative error. Each sample was chromatographed within6.0min.Conclusion The validated liquid chromatographic-tandem mass spectrometric method firstly used ESI(-) for the determination of zaltoprofen in human plasma and urine. Compared with reference methods, the method was sensitive, specific and successfully applyed to the pharmacokinetic study of zaltoprofen tablet.2. Quantitative analysis of tiopronin in human plasma and its applicationBackground Tiopronin is a derivative of glycine containing active thiol group. It can be used for the therapy of hepatitis, rheumatoid arthritis, cataract and cystinuria.Objective To develop and validate a specific, sensitive and rapid liquid chromatographic-tandem mass spectrometric method for determination of tiopronin in human plasma and application to the bioequivalence evaluation of tiopronin tablet.Method Determination of tiopronin in human plasma by liquid chromatography-tandem mass spectrometry. Afther reduction with DL-dithiothreitol (DTT), plasma samples were derivatizated with p-bromophenacyl bromide (p-BPB) and deproteinizated with acetonitrile, separated on a Zorbax XDB C18column (150×4.6mm I.D.,5μm) with the mobile phase consisted of methanol-10mmol·L-1ammonium acetate (65:35, v/v). A triple quadrupole mass spectrometry equipped with electrospray ionization source (ESI) source was used as the detector and operated in the negative ion mode. Quantitation was performed using seclective reaction monitoring (SRM) of the transitions of m/z358â†'m/z116(the derivative of tiopronin) and m/z362â†'m/z120(the derivative of d3,13C-tiopronin, internal standard).Results The linear concentration range of the calibration curve was5.00-5000ng·mL-1and the lower limit of quantification was5.00ng·mL-1. The intra-day and inter-day relative standard deviation were less than5.9%. The accuracy was in the range of-0.8to0.2%in terms of relative error. The mean analysis time was just4.5min.Conclusion Isotopically labeled internal standard was utilized to overcome matrix effect and minimized error. The validated liquid chromatographic-tandem mass spectrometric method was sensitive, specific, rapid and less plasma amount. It was well suited for routine high-throughput analyses, such as, those required for bioequivalence evaluation.