A VALIDATED LC-MS/MS BIOANALYTICAL METHOD FOR THE SIMULTANEOUS DETERMINATION OF THREE ACE-INHIBITORS IN HUMAN PLASMA

A selective and rapid LC-MS/MS spectrophotometric method has been developed and validated for the simultaneous determination of three ACE-inhibitors used in anti-hypertensive therapy, namely enalapril maleate, perindopril, and ramipril in human plasma using high-performance liquid chromatography-tandem mass spectrophotometry (LC-MS/MS) with electrospray ionization (ESI). Separation of analytes and internal standard; atorvastatin was performed on X-terra C8 (3.5 µm, 4.6 × 50 mm) column with a run time of 2 min. The mobile phase consisted of methanol: 20 mM ammonium formate, pH 6.3 ± 0.05 with formic acid (80:20, v/v). Analytes were extracted from human plasma using a simple protein precipitation technique with methanol, allowing fast analysis. The method was validated in terms of accuracy, precision, selectivity, recovery and stability as per FDA and EMA guidelines. The method showed linearity over the concentration range 4- 400 ng/mL, 2 – 200 ng/mL and 0.5 – 50 ng/mL for enalapril, perindopril and ramipril, respectively, applying weighted (1/X2) linear regression. The method is simple, fast, precise, accurate and suitable for its application for bioequivalence and pharmacokinetic studies.