Development and validation of high-throughput liquid chromatography-tandem mass spectrometric method for simultaneous quantification of loratadine and desloratadine in human plasma.

As a continuation of effort to improve our high flow on-line bioanalytical approach for high-throughput quantification of drugs and metabolites in plasma by high-throughput liquid chromatography tandem mass spectrometry (HTLC-MS/MS), we have developed a simple, sensitive and reliable method for simultaneous quantification of loratadine and desloratadine in human plasma. We have performed on-line coupling of extraction with Cyclone P 50 mm x 0.5 mm 50 microm HTLC column and chromatographic separation is performed with Zorbax XDB C18 50 mm x 2.1 mm 5 microm, followed by quantification with mass detector. The method is validated and showed good performances in terms of linearity, sensitivity, precision, accuracy and stability. A marked improvement in sample throughput efficiency is realized with this method and the proposed method will be useful for pharmacokinetic and/or bioequivalence studies.

Development and validation of a HPLC method for the determination of voriconazole in pharmaceutical formulation using an experimental design.

A rapid and sensitive RP-HPLC method with UV detection (260nm) for routine analysis of voriconazole in a pharmaceutical formulation (Vfend((R))) was developed. Chromatography was performed with mobile phase containing a mixture of acetonitrile and water (50:50, v/v) with flow rate was of 1.0mlmin(-1). Quantitation was accomplished with internal standard method. The procedure was validated for linearity (correlation coefficient=0.9999), accuracy, robustness and intermediate precision. Experimental design was used for validation of robustness and intermediate precision. To test robustness, three factors were considered. Percentage of acetonitrile in mobile phase, flow rate and p(H); an increase in the flow rate results in a decrease of the drug found concentration, while the percentage of organic modifier and p(H) have no important effect on the response. For intermediate precision measure the variables considered were: analyst, equipment and number of days. The R.S.D. value (0.45%, n=24) indicated a good precision of the analytical method. The proposed method was simple, highly sensitive, precise and accurate and retention time less than 4min indicating that the method is useful for routine quality control.