Mahesh, H. R. K.; Babu, K. Sudhakar; Ram Prasad, Lanka A.; Pamidi, Srinivasu published an article in 2015, the title of the article was Simultaneous estimation of related compounds in Esomeprazole and Naproxen tablets by using ion pair reverse phase HPLC.Safety of 5-Methoxy-2-[[(4-methoxy-3,5-dimethyl-2-pyridyl)methyl]thio]benzimidazole And the article contains the following content:
Objective: To develop and validate a novel gradient reverse phase HPLC method for quant. estimation of Naproxen and Esomeprazole impurities in pharmaceutical dosage form. Methods: Chromatog. separation was achieved on X-Bridge C18,150 × 4.6 mm, 3.5 μm column. Detection wavelength was set at 302 nm. The mobile phase A consists of Buffer and Acetonitrile in the ratio of 90:10, where Buffer was prepared by dissolving di ammonium hydrogen phosphate (2.64 gm per L) and 1-hexane sulfonic acid sodium salt (1.0 gm per L), pH adjusted to 6.5±0.05 with orthophosphoric acid. A mixture of acetonitrile and 1-propanol in the ratio of 90:10 was used as mobile phase B. Flow rate was set to 0.7 mL/min in gradient elution mode, with a retention time for Naproxen and Esomeprazole 29 and 46 min resp. Results: The calibration curve was linear over the concentration range of 4.621 μg/mL-99.026 μg/mL for Naproxen and 0.254 μg/mL-3.806 μg/mL for Esomeprazole (r = 0.999). The proposed method was found to be (considered)accurate and precise and linear within the desired range. The limit of quantitation (LOQ) was calculated The purity angle was found less than purity threshold for forced degradation peaks, which shows there was no interference from the common excipient, known impurities and degradents indicating separation, accuracy and reliability of the method. The method was validated as per ICH guidelines and found to be specific, accurate, linear, precise and stability indicating. Conclusion: A Novel, simple, selective and rapid reversed phase high performance liquid chromatog. (HPLC) method was developed and validated for the estimation of Naproxen and Esomeprazole impurities in pharmaceutical dosage form. Hence, the method can be used for routine anal. in various pharmaceutical industries. The experimental process involved the reaction of 5-Methoxy-2-[[(4-methoxy-3,5-dimethyl-2-pyridyl)methyl]thio]benzimidazole(cas: 73590-85-9).Safety of 5-Methoxy-2-[[(4-methoxy-3,5-dimethyl-2-pyridyl)methyl]thio]benzimidazole
The Article related to esomeprazole naproxen tablet reverse phase hplc, Pharmaceutical Analysis: Synthetic Organic Compounds and other aspects.Safety of 5-Methoxy-2-[[(4-methoxy-3,5-dimethyl-2-pyridyl)methyl]thio]benzimidazole
Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem