A simple, selective and rapid validated method for estimation of anastrazole in human plasma by liquid chromatography-tandem mass spectrometry and its application to bioequivalence study

A Review on Liquid Chromatography-Tandem Mass Spectrometry Methods for Rapid Quantification of Oncology Drugs

In the last decade, the tremendous improvement in the sensitivity and also affordability of liquid chromatography-tandem mass spectrometry (LC-MS/MS) has revolutionized its application in pharmaceutical analysis, resulting in widespread employment of LC-MS/MS in determining pharmaceutical compounds, including anticancer drugs in pharmaceutical research and also industries. Currently, LC-MS/MS has been widely used to quantify small molecule oncology drugs in various biological matrices to support preclinical and clinical pharmacokinetic studies in R&D of oncology drugs. This mini-review article will describe the state-of-the-art LC-MS/MS and its application in rapid quantification of small molecule anticancer drugs. In addition, efforts have also been made in this review to address several key aspects in the development of rapid LC-MS/MS methods, including sample preparation, chromatographic separation, and matrix effect evaluation.

Development and validation of a rapid LC-MS/MS method to quantify letrozole in human plasma and its application to therapeutic drug monitoring

A selective, rapid, and sensitive liquid chromatography-tandem mass spectrometry(LC-MS/MS) method was developed and validated for the determination of letrozole (LTZ) in human plasma, using anastrozole as internal standard (IS). Sample preparation was performed by one-step protein precipitation with methanol. The analyte and IS were chromatographed on a reversed-phase YMC-ODS-C18 column (2.0 × 100 mm i.d., 3 µm) with a flow rate of 0.3 mL/min. The mobile phase consisted of water containing 0.1% formic acid (v/v) and methanol containing 0.1% formic acid (v/v). The mass spectrometer was operated in selected reaction monitoring mode through electrospray ionization ion mode using the transitions of m/z 286.2 → 217.1 for LTZ and m/z 294.1 → 225.1 for IS, respectively. The method was validated for selectivity, linearity, lower limit of quantitation, precision, accuracy, matrix effects and stability in accordance with the US Food and Drug Administration guidelines. Linear calibration curves were 1.0-60.0 ng/mL. Intra- and inter-batch precision (CV) for LTZ were <9.34%, and the accuracy ranged from 97.43 to 105.17%. This method was successfully used for the analysis of samples from patients treated with LTZ in the dose of 2.5 mg/day. It might be suitable for therapeutic drug monitoring of these patients and contribute to predict the risk of adverse reactions.

An ultraperformance liquid chromatography-tandem mass spectrometry method for determination of anastrozole in human plasma and its application to a pharmacokinetic study

A fast, selective and sensitive ultraperformance liquid chromatography-tandem mass spectrometry method was developed for determination and pharmacokinetic study of anastrozole in human plasma. Plasma sample pretreatment involved a one-step extraction with diethyl ether of 500 µL plasma. The chromatographic separation was carried out on an Acquity UPLC(TM) BEH C(18) column with a mobile phase consisting of methanol-10  mmol/L ammonium acetate (75:25, v/v) at a flow rate of 0.30 mL/min. The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring via electrospray ionization source with positive mode. A high throughput was achieved with a run time of 1.5 min per sample. The standard curve for anastrozole was linear (r(2) ≥ 0.99) over the concentration range of 0.0550-27.5 ng/mL with a lower limit of quantification of 0.0550 ng/mL. The intra- and inter-day precision (relative standard deviation) values were not higher than 14% and the accuracy (relative error) was within ±3.2% at three quality control levels. This simple, fast and highly sensitive method was fully validated and successfully applied to a clinical pharmacokinetic study of anastrozole in healthy volunteers after oral administration.