Quantification of desloratadine in human plasma by LC-ESI-MS/MS and application to a pharmacokinetic study / 药物分析学报

A simple,sensitive,and specific liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed for the quantification of desloratadine (DL) in human plasma using desloratadine-d5 (DLD5) as an internal standard (IS).Chromatographic separation was performed using an Xbridge C18 column (50 mm × 4.6 mm,5 μm) with an isocratic mobile phase composed of 10 mM ammonium formate:methanol (20∶80,v/v),at a flow rate of 0.7 mL/min.DL and DLD5 were detected with proton adducts at m/z 311.2→259.2 and 316.2→264.3 in multiple reaction monitoring (MRM)positive modes,respectively.Liquid-liquid extraction (LLE) method was used to extract the drug and the IS.The method was validated over a linear concentration range of 5.0-5000.0 pg/mL with a correlation coefficient of (r2)(≥)0.9994.This method demonstrated intra- and inter-day precision within 0.7-2.0％ and 0.7-2.7％,and an accuracy within 101.4-102.4％,and 99.5-104.8％.DL was found to be stable throughout the freeze-thaw cycles,bench-top,and postoperative stability studies.This method was successfully applied in the analysis of plasma samples following oral administration of DL (5 mg) in 35healthy Indian male human volunteers under fasting conditions.

Quantification of sibutramine and its two metabolites in human plasma by LC-ESI-MS/MS and its application in a bioequivalence study / 药物分析学报

Obesity can be considered as a chronic illness of epidemic proportion and its incidents have increased exponentially in recent years.The use of anti-obesity drugs such as sibutramine is somewhat helpful.There is a need to quantify such drugs in biological samples,which is generally quite difficult.In this report,we developed and validated a simple,sensitive and specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantification of sibutramine (SB) and its two metabolites N-des methyl sibutramine (DSB) and N-di desmethyl sibutramine (DDSB) in human plasma.Zorbax SBC18 (4.6 mm × 75 mm,3.5 μm,80 (A)) analytical column and 5 mM ammonium formate:acetonitrile (10∶90,v/v) mobile phase were used for chromatographic separation of SB,DSB and DDSB.Multiple reaction monitoring (MRM) in the positive mode was used to detect SB,DSB and DDSB at m/z 280.3/124.9,266.3/125.3 and 252.2/124.9,respectively.Liquid liquid extraction was used for the extraction of analytes and internal standard from human plasma.This method was validated over a linear concentration range of 10.0-10,000.0 pg/mL for SB,DSB and DDSB with correlation coefficients (r) of ≥0.9997.The drug and the two metabolites were stable in plasma samples.The validated method was successfully applied in a bioequivalence and pharmacokinetic study with human volunteers under fasting condition.