Abstract
Three simple, sensitive, and specific methods were developed for simultaneous determination of amlodipine besylate (AML) and Perindopril Erbumine (PER) without previous separation. The first method was dependent on the first derivative of the ratio spectra by measuring the amplitudes at 348nm for amlodipine using 50 mu gmL1 of perindopril as a divisor and at 227nm for perindopril using 30 mu gmL1 of amlodipine as a divisor. The second method was based on ion-pair RP-HPLC. Satisfactory resolution was achieved using RP-C18 chromatographic column Zorbax Extend column and a mobile phase consists of potassium dihydrogen phosphate buffer (0.05M, pH 3.0 +/- 0.02 adjusted by orthophosphoric acid): acetonitrile 30:70 v/v at a flow rate 1mL/min using 0.002M sodium heptanesulfonate in the aqueous phase. UV detection was performed at 215nm. The third method was based on TLC; the separation was carried out on Fluka TLC aluminum sheets silica gel 60F254, using n-butanol:water:glacial acetic acid (4:5:1, v/v/v) as the mobile phase. The validation of the proposed methods was applied according to ICH guidelines and LOD and LOQ were calculated. The suggested methods were successfully applied for the determination of the cited drugs in bulk powder and commercial tablets.