Abstract
Validated LC-MS/MS assay for the determination of ramipril levels in human plasma
Author(s): Syed N.Alvi, Saleh Al-Dgither, Muhammad M.HammamiA rapid, specific and sensitive liquid chromatographic-tandemmass spectrometric (LC-MS/MS) assay for the determination of ramipril levels in human plasma has been developed and validated. Enalapril was used as internal standard (IS). Protein precipitation using methanol in acidic medium yielded clean extracts with a consistent recovery of about 87 %. Analysis was performed on Waters Atlantis C18 column using a mobile phase of 0.1%formic acid andmethanol (10:90, v:v). The eluentwasmonitored using tandem mass spectrometry electrospray ionization and multiple reaction monitoring (MRM) method. The peak height of the transition for ramipril m/z 417.3 234.3 was measured against that of IS m/z 377.3234.2 to generate the standard curves. The relationship between ramipril concentration and peak height ratio (ramipril/IS) was linear over the range 0.5-80 ng/ml in human plasma. The intra-day and inter-day coefficients of variation were 7.0 and 10.2, respectively. The method was applied to assess the stability of ramipril under various conditions generally encountered in the clinical laboratory. Ramipril in plasma was stable for at least 24 hr at RT, 3 months at -20ºC, and after three freeze-thaw cycles.
