Authors:Michael El-Kommos, Pakinaz Khashaba, and Mohamed El-Wekil
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 quantitation limits were 145.59–222.47 and 93.14–98.48 ng spot−1, respectively. For method B, Beer’s law was obeyed for omeprazole, clarithromycin, and tinidazole in the concentration range of 180–480, 2250–6000, and 30–180 ng spot−1, respectively. The detection limits for omeprazole, clarithromycin, and tinidazole were 20.36, 272.60, and 2.05 ng spot−1, respectively, and the quantitation limits were 61.7, 825.9, and 6.2 ng spot−1, respectively, for the investigated drugs.
Authors:Nejal M. Bhatt, Vijay D. Chavada, Mallika Sanyal, and Pranav S. Shrivastav
In the present study, a simple and effcient high-performance thin-layer chromatographic (HPTLC) method was developed for the separation and quantitation of three proton-pump inhibitors, omeprazole, pantoprazole, and rabeprazole, from their binary combinations with diclofenac. Using a “quality by design” approach, preliminary trials were performed on pre-coated silica gel HPTLC plates using toluene together with various alcohols (methanol, ethanol, iso-propanol, n-butanol) as the mobile phase. For better peak symmetry, ammonia was added in different volumes, and its effect on analyte retention and separation was also assessed. The mobile phase consisting of toluene–n-butanol-25% ammonia (3:7:0.2, v/v) afforded excellent separation of proton-pump inhibitors from diclofenac as well as from each other. The retardation factor (RF) for all the separated compounds was between 0.20 and 0.80. The developed method was successfully validated as per the International Conference on Harmonization (ICH) guidelines, and the selected drugs were determined simultaneously from dosage forms without any interference from the excipients.
., Amaral, L., Molnár, J.:
Enhancement of plasmid curing by 9-aminoacridine and two phenothiazines in the presence of protonpumpinhibitor 1-(2-benzoxazolyl)-3,3,3-trifluoro-2-propanone. Int. J. Antimicrob. Agents, 2003,