title: Determination of rosuvastatin in rat plasma by HPLC: Validation and its application to pharmacokinetic studies.
abstract: A specific, accurate, precise and reproducible high-performance liquid chromatography (HPLC) method was developed for the estimation of rosuvastatin (RST), a novel, synthetic and potent HMG-CoA inhibitor in rat plasma. The assay procedure involved simple liquid-liquid extraction of RST and internal standard (IS, ketoprofen) from a small plasma volume directly into acetonitrile. The organic layer was separated and evaporated under a gentle stream of nitrogen at 40 degrees C. The residue was reconstituted in the mobile phase and injected onto a Kromasil KR 100-5C18 column (4.6 x 250 mm, 5 microm). Mobile phase consisting of 0.05 m formic acid and acetonitrile (55:45, v/v) was used at a flow rate of 1.0 mL/min for the effective separation of RST and IS. The detection of the analyte peak was achieved by monitoring the eluate using a UV detector set at 240 nm. The ratio of peak area of analyte to IS was used for quantification of plasma samples. Nominal retention times of RST and IS were 8.6 and 12.5 min, respectively. The standard curve for RST was linear (r2 > 0.999) in the concentration range 0.02-10 microg/mL. Absolute recoveries of RST and IS were 85-110 and >100%, respectively, from rat plasma. The lower limit of quantification (LLOQ) of RST was 0.02 microg/mL. The inter- and intra-day precisions in the measurement of quality control (QC) samples, 0.02, 0.06, 1.6 and 8.0 microg/mL, were in the range 7.24-12.43% relative standard deviation (RSD) and 2.28-10.23% RSD, respectively. Accuracy in the measurement of QC samples was in the range 93.05-112.17% of the spiked nominal values. Both analyte and IS were stable in the battery of stability studies, viz. benchtop, autosampler and freeze-thaw cycles. RST was found to be stable for a period of 30 days on storage at -80 degrees C. The application of the assay to determine the pharmacokinetic disposition after a single oral dose to rats is described.
authors.affiliation: Drug Metabolism and Pharmacokinetics, Discovery Research, Dr Reddy's Laboratories Ltd, Miyapur, Hyderabad 500 049, India.
authors.forename: Thammera Ranjith
authors.initials: TR
authors.lastname: Kumar
authors.forename: Nikhil R
authors.initials: NR
authors.lastname: Shitut
authors.forename: Pasikanti Kishore
authors.initials: PK
authors.lastname: Kumar
authors.forename: Menon C A
authors.initials: MC
authors.lastname: Vinu
authors.forename: Venkata V Pavan
authors.initials: VV
authors.lastname: Kumar
authors.forename: Ramesh
authors.initials: R
authors.lastname: Mullangi
authors.forename: Nuggehally R
authors.initials: NR
authors.lastname: Srinivas
mesh_terms: D000818:Animals; D002138:Calibration; D005464:Fluorobenzenes / Q000097:blood* / Q000493:pharmacokinetics; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000097:blood* / Q000493:pharmacokinetics; D008297:Male; D011743:Pyrimidines / Q000097:blood* / Q000493:pharmacokinetics; D051381:Rats; D017208:Rats, Wistar; D012015:Reference Standards; D015203:Reproducibility of Results; D000068718:Rosuvastatin Calcium; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet; D013449:Sulfonamides / Q000097:blood* / Q000493:pharmacokinetics
chemical_list: D005464:Fluorobenzenes; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D011743:Pyrimidines; D013449:Sulfonamides; D000068718:Rosuvastatin Calcium