title: Improvement of the chromatographic separation of several 1,4-dihydropyridines calcium channel antagonist drugs by experimental design.
abstract: A high-performance liquid chromatographic method with diode array detection has been developed and optimized for the separation of five calcium channel blockers belonging to the 1,4-dihydropyridine subgroup (nifedipine and related drugs). The possibility of the simultaneous drug analysis allows a decrease of time during the assay as well as a saving of reagents and solvents. In this work, the effect of four experimental parameters (organic modifier percentage, pH value, concentration of the buffer in the mobile phase, and column temperature) on the chromatographic resolution are investigated by experimental design in order to optimize the chromatographic separation of five 1,4-dihydropyridines (amlodipine, nitrendipine, felodipine, lacidipine, and lercanidipine). Fractional factorial design, central composite design, and finally the Multisimplex program are used to establish the optimal conditions in terms of resolution and minimum analysis time. Optimal separation of the five compounds under study is achieved in less than 12 min using a Sulpecosil LC-ABZ+Plus C18 column, a composition of mobile phase of acetonitrile-10mM acetic acid acetate buffer pH 5 (72:28, v/v) at a flow rate of 1 mL/min, a column temperature of 30 degrees C +/- 0.1 degrees C, and a detection wavelength of 238 nm.
authors.affiliation: Departamento de Química Analítica, Facultad de Ciencia y Tecnología, Universidad del País Vasco/EHU, Apdo. 644, E-48080 Bilbao, Spain.
authors.forename: Ana B
authors.initials: AB
authors.lastname: Baranda
authors.forename: Nestor
authors.initials: N
authors.lastname: Etxebarria
authors.forename: Rosa M
authors.initials: RM
authors.lastname: Jiménez
authors.forename: Rosa M
authors.initials: RM
authors.lastname: Alonso
mesh_terms: D002121:Calcium Channel Blockers / Q000302:isolation & purification*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004095:Dihydropyridines / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D013056:Spectrophotometry, Ultraviolet; D013696:Temperature
chemical_list: D002121:Calcium Channel Blockers; D004095:Dihydropyridines; C038806:1,4-dihydropyridine