Novel ecofriendly spectrophotometric methods for the determination of six dihydropyridines calcium channel blockers through derivatization with sulfophtalein dye: application to tablet analysis.

Novel, «green» and simple visible spectrophotometric procedures for the determination of six dihydropyridines CCBs (amlodipine besylate (AML), lacidipine (LAC), levamlodipine besylate (LAML), nifedipine (NIF), nimodipine (NIM) and nitrendipine (NIT)) through derivatization with the sulfophthalein dye bromophenol blue (BPB) have been developed. The optimal parameters for CCBs spectrophotometric analysis via complex formation using BPB were as follows: detection wavelength-596 nm, reaction time-5 min, ratio of reacting components-1:1, operating temperature-25 ± 2 °C. The concentration was linearly proportional to absorbance values in the range of 3.

Four ecofriendly spectrophotometric methods for the determination of perindopril through derivatization with sulphophtalein dyes: application to tablet analysis.

Nowadays, there is a need to expand the bank of spectrophotometric methods for the determination of perindopril in dosage forms for the purposes of routine pharmaceutical analysis, which would be simple, express, «green» and inexpensive. In the present work, perindopril in tablets was quantified via a direct simple, «green», and non-extracting spectrophotometric approach based on the formation of ion-pair complexes with sulphophtalein dyes. The absorbances of the colored reaction products were registered at 405 nm (bromocresol green, BCG), 397 nm (bromocresol purple, BCP, and bromothymol blue, BTB) and 598 nm (bromophenol blue, BPB).