LC-MS/MS determination and pharmacokinetic study of lacidipine in human plasma

A robust, specific and fully validated LC-MS/MS method as per general practices of industry has been developed for estimation of lacidipine (LAC) with 100 μL of human plasma using lacidipine-(13) C8 as an internal standard (IS). The API-4000 LC-MS/MS was operated under the multiple reaction-monitoring mode. A simple liquid-liquid extraction process was used to extract LAC and IS from human plasma. The total run time was 3.0 min and the elution of LAC and IS occurred at 1.96 and 1.97 min; this was achieved with a mobile phase consisting of 5 mm ammonium acetate buffer-acetontrile (15:85 v/v) at a flow rate of 0.60 mL/min on a Zorbax SB C18 (50 × 4.6 mm, 5 µm) column. A linear response function was established for the range of concentrations 50-15,000 pg/mL (r > 0.998) for LAC. The current developed method has negligible matrix effect and is free from unwanted adducts and clusters which are formed owing to system such as solvent or mobile phase. The developed assay method was applied to an oral pharmacokinetic study in humans and successfully characterized the pharmacokinetic data up to 72 h.