Niacin and its metabolites: role of LC-MS/MS bioanalytical methods and update on clinical pharmacology. An overview.

Niacin (nicotinic acid), although an old drug, has seen a sudden surge in popularity for treatment of lipid disorders and other associated clinical conditions for the prevention of cardiovascular risk. Also, there has been considerable interest in clarifying the role of metabolic pathways of niacin in explaining the tolerability/adverse affect profile of the agent. Hence, it has become very important to quantify/monitor the levels of niacin and its metabolites in various clinical studies. This review describes the recent trends in the bioanalysis of niacin and its metabolites, where HPLC and LC-MS/MS assays have been successfully employed to measure the drug levels in various biological matrices arising from preclinical and clinical studies. In addition, this review encompass various considerations such as internal standard selection, extraction schemes, matrix effect, selectivity evaluation and optimization of mass spectral conditions to enable the development of sound bioanalytical methods for niacin alone or niacin along with its metabolites. Recent updates pertaining to the clinical pharmacology of niacin and ongoing debate for the clarification of adverse effects are also provided. Overall LC-MS/MS methods have proven to be choice of bioanalytical method for the quantification of niacin alone or with its metabolites in both preclinical and clinical studies. 2010 John Wiley & Sons, Ltd.