Quantification of Palbociclib in Spiked Human Plasma Using Liquid Chromatography- Electro Spray Ionization-tandem Mass Spectrophotometry- an Application to Pharmacokinetic Study

Objectives: The present method was developed for the estimation of palbociclib in spiked human plasma using Liquid chromatographic mass spectroscopy. Methods: The liquid-liquid extraction method was adopted and chromatographic separation was performed on a waters symmetry shield, C-18(4.6mm id x 50 mm) analytical column using (methanol: ultrapure water, pH 4.2 in the volume ratio of 60:40) as mobile phase. Positive ion mode was selected to obtain the product m/z +447.5 (parent) -> 380.3 (product) for palbociclib and m/z +434.5 (parent) -> 322.7 (product) for internal standard. Results: Calibration curve was linear over the range of 3-600 ng/ml. The intra and interday accuracy with % nominal 95 -> 98.4 %, precision %CV <= 2% in all quality control levels, The percentage extraction recovery (96.15 % -> 98.34 %), demonstrated excellent matrix and analyte selectivity (% interference = 0), and satisfactory stability study results in all types (% nominal 93.91 % -> 99.58 %). The pharmacokinetic parameters was studied in the rabbit model, and the area under the curve (AUC(0-infinity)) for palbociclib was 2632 +/- 6.98 hr.ng/ml. The elimination half-life (t(1/2)) is 11.3 +/- 5.3 hr. Conclusion: Based on the experimental findings the current developed method was considered a novel validated bioanalytical method, and applied in rabbit blood samples for pharmacokinetic studies of marketed formulations.