Method development and validation of HPLC tandem/mass spectrometry for quantification of perindopril arginine and amlodipine besylate combination in bulk and pharmaceutical formulations.

A well-characterized and fully validated ultra-high performance liquid chromatography-electrospray ionization-tandem mass spectrometric (UHPLC-ESI-MS/MS) method was developed to reliably analyze combination of perindopril arginine and amlodipine besylate in bulk and tablet formulations. The chromatographic separation was achieved on a Waters ACQUITY UPLC® BEH C18 column with 1.7 µm particle packing which enabled the higher peak capacity, greater resolution, increased sensitivity, and higher speed of analysis using a volatile mobile phase ideally being at least 2 pH units below and above the perindopril arginine and amlodipine besylate pKa, respectively. Mass spectrometric detection was performed using electrospray ion source in positive ion polarity to profile the abundances of perindopril arginine and amlodipine besylate, using the transitions m/z 369 → m/z 172, and m/z 409 → m/z 238 for perindopril arginine and amlodipine besylate, respectively. Calibration curve was constructed over the range 0.25 - 500 ng/mL and 1.0 - 100 ng/mL for perindopril arginine and amlodipine besylate, respectively. The method was precise and accurate, and provided recovery rates > 80% for both compounds. Furthermore, the intra- and inter-assay precision in terms of % RSD was in between 0.1 - 3.7 for both perindopril arginine and amlodipine besylate. A specific, accurate, and precise UHPLC-MS/MS method for the determination of perindopril arginine and amlodipine besylate in bulk and tablet formulation.

Electromembrane extraction--a novel extraction technique for pharmaceutical, chemical, clinical and environmental analysis.

Electromembrane extraction (EME) is a novel sample preparation technique in pharmaceutical, chemical, clinical and environmental analysis. This technique uses electromigration across artificial liquid membranes for selective extraction of analytes and sample enrichment from complex matrices. This review focuses on the setup, general procedure and parameters affecting the extraction efficiency of EME. An overview of innovations in EME (on-chip EME, low voltage EME, drop-to-drop EME, pulsed EME and EME followed by low-density solvent based ultrasound-assisted emulsification microextraction) is also presented in this article and attention is focused on the use of EME for pharmaceutical, chemical, clinical and environmental analysis.