A simple, rapid, specific and precise liquid chromatography—tandem mass spectrophotometric (LC-MS/MS) method was developed and validated for the quantification of chiral separated R-bicalutamide from S-bicalutamide, in human plasma. Topiramate (TPM) was used as internal standard, added to plasma sample prior to extraction using t-butyl methyl ether (TBME). Chromatographic separation was achieved on CHIRALPAK AD-RH column (150 mm×4.6 mm, 5 μm) with acteonitrile: 0.1% formic acid Buffer (50:50 v/v) as an isocratic mobile phase with a flow rate of 1.0 mL·min-1. Quantitation was performed by transition of 429.0 → 255.0 (m/z) for R-bicalutamide and 338.1 → 77.8 (m/z) for topiramate. The lower limit of quantitation was 20 ng·mL-1with a 100 μL plasma sample. The concentrations of eight working standards showed linearity between 20 to 3200 ng·mL-1(r2≥ 0.9990). Chromatographic separation was achieved within 6 min, compared to the 15 min of previous methods. The average extraction recoveries of 3 quality control concentrations were 98.56% for R-bicalutamide and 92.42% for topiramate. The coefficient of variation was ≤15% for intra- and inter-batch assays. Therefore a rapid, specific and sensitive LC-MS/MS method for the quantification of R-bicalutamide in human plasma was developed and validated can be used in the bioequivalence study of this drug.
 S. Lee, Y. J. Chung, B. H. Kim, J. H. Shim and S. H. Yoon, “Comparative Pharmacokinetic Evaluation of Two Formulations of Bicalutamide 50-mg Tablets: An Open Label, Randomized-Sequence, Single-Dose, Two-Period Crossover Study in Healthy Korean Male Volunteers,” Clinical Therapeutics, Vol. 31, No. 12, 2009, pp. 3000 3008. doi:10.1016/j.clinthera.2009.12.004
 R. NageswaraRao, A. NarasaRaju and D. Nagaraju, “An Improved and Validated LC Method for Resolution of Bicalutamide Enantiomers Using Amylase Tris-(3,5-Ime thylphenylcarbamate) as a Chiral Stationary Phase. Journal of Pharmaceutical and Biomedical Analysis, Vol. 42, No. 3, 2006, pp. 347-353. doi:10.1016/j.jpba.2006.04.014
 D. McKillop, G. W. Boyle, I. D. Cockshott, D. C. Jones, P. J. Phillips, et al. “Metabolism and Enantioselective Pharmacokinetics of Casodex in Man,” Xenobiotica, Vol. 23, No. 11, 1993, pp. 1241-1253. doi:10.3109/00498259309059435
 F. Boccardo, A. Rubagotti, G. Conti, D. Potenzoni, A. Manganelli and D. Del Monaco, “Exploratory Study of Drug Plasma Levels during Bicalutamide 150 mg Therapy Co-Administered with Tamoxifen or Anastrozole for Prophylaxis of Gynecomastia and Breast Pain in Men with Prostate Cancer,” Cancer Chemotherapy and Pharmacology, Vol. 56, No. 4, 2005, pp. 415-420. doi:10.1007/s00280-005-1016-1
 US Food and Drug Administration, “Guidance for Indus try. Bioavailability and Bioequivalence Studies for Orally Administered Drug Products-General Considerations,” 2009. www.fda.gov/downloads/Drugs/.../Guidances/ucm070124