Development and validation of an improved LC-MS/MS method for the quantification of desloratadine and its metabolite in human plasma using deutrated desloratadine as internal standard.

PURPOSE: For the determination of desloratadine (DES) and 3-OH desloratadine (3-OHD) in human plasma using deutrated desloratadine (DESD5) as internal standard (IS), a novel stability indicating liquid chromatography-tandem mass spectrometric method was developed and validated to support the clinical advancement. MATERIALS AND METHODS: The solid-phase extraction method used for sample preparation and calibration range was 100-11,000 pg/ml, for which a quadratic regression (1/x(2)) was best fitted. The blank plasma was screened and observed free from any endogenous interference. RESULTS: The accuracy (% nominal) at low limit of quantification LLOQ level for DES and 3-OHD was 100.4% and 99.9% whereas precision (%CV) was 4.6 and 5.1%. They (DES and 3-OHD) were stable in human plasma after five freeze-thaw cycles, at room temperature for 23.8 hour, bench top stability for 6.4 hour. CONCLUSION: This method fulfills all the regulatory requirements for selectivity, sensitivity, precision, accuracy, stability, goodness of fit, and ruggedness of the method for the determination of DES and 3-OHD in human plasma.

Development and validation of LC-MS/MS method for the quantitation of lenalidomide in human plasma using Box-Behnken experimental design.

For the determination of lenalidomide using carbamazepine as an internal standard, an ultra-fast stability indicating LC-MS/MS method was developed, validated and optimized to support clinical advancement. The samples were prepared by solid-phase extraction. The calibration range was 2-1000 ng mL(-1), for which a quadratic regression (1/x(2)) was best fitted. The method was validated and a 3(2) factorial was employed using Box-Behnken experimental design for the validation of robustness. These designs have three factors such as mobile phase composition (X(1)), flow rate (X(2)) and pH (X(3)) while peak area (Y(1)) and retention time (Y(2)) were taken as response. This showed that little changes in mobile phase and flow rate affect the response while pH has no affect. Lenalidomide and carbamazepine were stable in human plasma after five freeze thaw cycles, at room temperature for 23.7 h, bench top stability for 6.4 h. This method competes with all the regulatory requirements for selectivity, sensitivity, precision, accuracy, and stability for the determination of lenalidomide in human plasma, as well as being highly sensitive and effective for the pharmacokinetic and bioequivalence study of lenalidomide.