UPLC-MS/MS Method for Kinetic Studies and Simultaneous Determination of Amlodipine and Atorvastatin in Bulk, and Their Combined Dosage FormAuthor(s): Ahmed M, Alshabrawy A and Nageh A
The aim of this work was to develop and validate a simple, sensitive and rapid method for the simultaneous quantitation of amlodipine and atorvastatin in bulk and their combined pharmaceutical formulation and application of method in forced degradation study. The chromatographic separation was achieved on a 50 mm × 2mm, 1.9 μm Hypersil gold column, with gradient elution. The analytes were detected using selective reaction monitoring (SRM) mode on a triple quadrupole mass spectrometer coupled with electrospray ionization (ESI) worked in positive mode and negative mode for Amlodipine (AMO) and Atorvastatin (ASN) respectively. The detection was done by monitoring of 409.47 → 238.22 (m/z), 557.65 → 397.27 (m/z), and 256.15 → 167.07 (m/z) for amlodipine, atorvastatin and diphenhydramine (IS) respectively. The method was validated over concentration range of (3-50) ng/mL and (0.8-50) ng/mL for Amlodipine (AMO) and Atorvastatin (ASN) respectively, for its linearity, robusticity, intra- and inters- day reproducibility. The lower limits of detection (LOD) were found to be 0.23 ng/mL and 0.56 ng/mL and lower limits of quantitation (LOQ) were found to be 0.69 ng/mL and 1.7 ng/mL for amlodipine and atorvastatin respectively. The method was applied successfully to quantitate atorvastatin and amlodipine in laboratory bulk mixture and their combined pharmaceutical dosage form. Also this method was used in stressed degradation study for identification of degradation products and calculation of kinetic parameters.