Pattarawit Rukthong. Determination of atorvastatin in human plasma with solid phase micro-extraction followed by LC MS/MS method and its application to pharmacokinetics study . Master's Degree(Pharmaceutics). Mahidol University. : Mahidol University, 2007.
Determination of atorvastatin in human plasma with solid phase micro-extraction followed by LC MS/MS method and its application to pharmacokinetics study
Abstract:
Determination of drugs in human plasma using the HPLC technique has been widely
accepted as an effective method owing to its practical applicability in routine drug analysis in
clinical trials. Nevertheless, the method sensitivity can be compromised once limited sample
volume is available. This problem is typically encountered in pharmacokinetics studies from
which small volume of plasma samples either form humans or animals can be obtained.
Atorvastatin, an HMG-CoA reductase inhibitor widely prescribed for the treatment of
hypercholesterolemia and the prevention of cardiovascular diseases was selected as a model
drug in this study. Drug extraction from human plasma was performed with the aid of
reversed-phase C18 solid phase micro-extraction. The detection was accomplished by triple
quandruple mass spectrometer interfaced operated in electrospray positive ion mode.
Quantitation was achieved by using multiple reaction monitoring (MRM) precursorproduction
transitions at m/z 559.2 and 440.1 for atorvastatin and m/z 412.2 and 224.2 for
fluvastatin (internal standard). Linearity was found within the atorvastatin concentration
range of 0.2-80 ng/ml. The limit of detection was found to be 0.05 ng/ml. The lower limit of
quantification was 0.1 ng/ml with a relative standard deviation (%RSD) of less than 12%.
Acceptable precision and accuracy were obtained for the concentrations within the calibration
curve range. The average recovery at low, medium and high of atorvastatin concentrations
from spiked plasma: quality control samples, were 84.16 ± 7.99%, 96.82 ± 6.14%, and 102.84
± 6.73%, respectively. The need for less than 250 ml of plasma volume each sample made it
possible to decrease sample preparation time. The method was successfully validated and
proved appropriate for the analysis of atorvastatin in human plasma and can be applied for
pharmacokinetics, bioavailability and bioequivalence studies.