Spectrodensitometric determination of some pharmaceutical mixtures containing proton pump inhibitors

Abstract

Two ultraviolet (UV)-spectrodensitometric methods were proposed for the separation and determination of binary and ternary mixtures containing proton pump inhibitors (PPIs). Method A was developed for the assay of omeprazole, panoprazole, rabeprazole, and lansoprazole in binary mixtures with domperidone (DOM) using their isoabsorptive points. Method B was developed for the determination of a ternary mixture containing omeprazole, tinidazole, and clarithromycin. It depends on using malonic acid-acetic anhydride as a spraying reagent to form yellow color (for omeprazole) and dark brown color (for clarithromycin) that are measured at λmax = 350 nm and λmax = 492 nm, respectively, while tinidazole was measured by UV at λmax = 310 nm. For method A, Beer’s law was obeyed for all studied PPIs and domperidone in the concentration range of 180–1440 and 120–720 ng spot−1, respectively. The detection limits for proton pump inhibitors and domperidone were 48.05–73.45 and 30.74–32.50 ng spot−1, respectively, and the q...