Quantification of sibutramine and its two metabolites in human plasma by LCâESI-MS/MS and its application in a bioequivalence study

• Main Authors: Venkata Suresh Ponnuru, B.R. Challa, RamaRao Nadendla
• Format: Article
• Language: English
• Published: Elsevier 2012-08-01
• Series: Journal of Pharmaceutical Analysis
• Online Access: http://www.sciencedirect.com/science/article/pii/S2095177912000408

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 chromatographyâtandem mass spectrometry (LCâMS/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 SB-C18 (4.6 mmÃ75 mm, 3.5 μm, 80 Å) 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. Liquidâliquid extraction was used for the extraction of analytes and internal standard from human plasma. This method was validated over a linear concentration range of 10.0â10,000.0 pg/mL for SB, DSB and DDSB with correlation coefficients (r) of â¥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. Keywords: LCâESI-MS/MS, Sibutramine, Human plasma, Bioequivalence, Pharmacokinetic study