Critical review of statins: A bio-analytical perspective for therapeutic drug monitoring

Statins are amongst the most prescribed agents worldwide for treating hypercholesterolaemia. This review summarizes bio-analytical techniques for monitoring of presently available seven statins- Atorvastatin, Rosuvastatin, Pitavastatin, Simvastatin, Lovastatin, Pravastatin and Fluvastatin with a special focus on sample preparation strategies and chromatographic analysis. Applications include determination of statins in various biological fluids like plasma, serum and urine. Apart from conventional extraction procedures of Protein precipitation, Liquid-liquid extraction and Solid-phase extraction, various novel extraction techniques like Micro-extraction by packed sorbent, Dispersive liquid-liquid micro-extraction, Salting-out assisted liquid-liquid extraction etc. are also used for sample clean-up. Extracted samples are usually separated by reverse-phase HPLC and quantitated either by UV or MS/MS detection. The importance and use of chromatographic techniques to separate drug-related biotransformation products are also discussed herein. Most bio-analytical techniques allow quantitation of statins in ng/ml range making them suitable for therapeutic monitoring of statins in routine.