Stability-indicating methods for the enantioselective determination of dihydropyridines by high performance liquid chromatography and capillary electrophoresis

Abstract

2012Stability-indicating methods for the enantioselective determination of dihydropyridines by high performance liquid chromatography and capillary electrophoresis ANALYTICAL METHODS, CAMBRIDGE, v. 4, n. 9, supl. 2, Part 3, pp. 2953-2961, SEP, 2012 This paper presents simple, rapid, precise and accurate stability-indicating HPLC and CE methods, which were developed and validated for the determination of nitrendipine, nimodipine and nisoldipine. These drugs are calcium channel antagonists of the 1,4-dihydropyridine type which are used in the treatment of cardiovascular diseases. Experimental results showed a good linear correlation between the area and the concentration of drugs covering a relatively large domain of concentration in all cases. The linearity of the analytical procedures was in the range of 2.0-120.0 mg mL À1 for nitrendipine, 1.0-100.0 mg mL À1 for nimodipine and 100.0-600.0 mg mL À1 for nisoldipine, the regression determination coefficient being higher than 0.99 in all cases. The proposed methods were found to have good precision and accuracy. The chemical stability of these drugs was determined under various conditions and the methods have shown adequate separation for their enantiomers and degradation products. In addition, degradation products produced as a result of stress studies did not interfere with the detection of the drugs' enantiomers and the assays can thus be considered stability-indicating.

Fourier Transform Infrared Spectroscopy, Thermogravimetric Analysis, Scanning Electron Microscopy as Supporting Tools in Quality Control of Antiparasitics

“…Therefore, TB has a good solubility in an acid medium. 19 Thus, acetonitrile mixtures with acid solutions were tested and among the different mixtures evaluated, the ratio of 95: 5 (acetonitrile: acetic acid) promoted complete solubility of the drug. Therefore, it was decided to use the solvent acetonitrile for all drugs, added to thiabendazole the acid solution.…”

“…11 Developing analytical methodologies to quantify pharmaceuticals involves assessing and optimizing conditions, including sample preparation stages, chromatographic separation, detection and quantification. [17][18][19][20][21] Among the analytical separation and quantification techniques, reverse phase high-performance liquid chromatography (RP-HPLC) with ultraviolet (UV) detection has been highlighted due to its significant resolution, low cost, precision and accuracy. [22][23][24] Bibliographical research in official compendia such the European and American Pharmacopoeias describes individual quantitative methods for the study of the pharmaceutical products FB and TB, but do not show those for FZ and TZ.…”

Practical and regulatory considerations for stability-indicating methods for the assay of bulk drugs and drug formulations

“…Chiral drugs containing a single labile stereogenic center require an additional chiral method to establish their stereochemical purity and stability [52][53][54]. Analogously, drugs exhibiting polymorphism need an additional proof of polymorphic identity if instability at this level affects the performance of the DS or the DP [55].…”