Analytical Chemistry Department, Faculty of Pharmacy, Cairo University, Kasr El-Aini St., 11562 Cairo, Egypt.
Pharmaceutical Chemistry Department, Faculty of Pharmaceutical Sciences and Pharmaceutical Industries, Future University in Egypt, 90th St., Fifth Settlement, New Cairo, Egypt.
J Chromatogr Sci. 2021 Oct 29;59(10):964-970. doi: 10.1093/chromsci/bmab037.
Two accurate and sensitive chromatographic methods have been introduced and validated for the simultaneous determination of thioctic acid, benfotiamine and cyanocobalamin in bulk powders and in their pharmaceutical formulation. Method A is reversed-phase ultra performance liquid chromatographic method with an isocratic elution, where a rapid separation was accomplished on a Zorbax C8 column using a mobile phase of acetonitrile:0.05 M phosphate buffer (pH 6 adjusted by o-phosphoric acid) (23:77, v/v). The retention times (tR) were 0.578, 0.852 and 1.376 for cyanocobalamin, benfotiamine and thioctic acid, respectively. The separated peaks were revealed at 210.0 nm. Method B is a thin-layer densitometric method where the separation of the studied drugs was carried out on silica gel plates using methanol-chloroform-heptane-1-sulphonic acid sodium salt (0.4%) (7:3:0.1, by volume) as a mobile phase, and scanning of the separated bands was done at 240.0 nm. The retardation factor (Rf) values were 0.17, 0.48 and 0.75 for cyanocobalamin, benfotiamine and thioctic acid, respectively. Validation of the methods was achieved following ICH guidelines and the applied methods succeeded to determine the cited drugs in their pure forms and capsules. Results were statistically compared to the manufacturer's method where no significant difference was observed.
两种准确、灵敏的色谱方法已被引入并验证，可用于同时测定散装粉末和制剂中的硫辛酸、苯磷硫胺和氰钴胺。方法 A 是反相超高效液相色谱法，采用等度洗脱，在 Zorbax C8 柱上，以乙腈：0.05 M 磷酸缓冲液（pH 6 用邻磷酸调）（23:77，v/v）为流动相，可快速分离。氰钴胺、苯磷硫胺和硫辛酸的保留时间（tR）分别为 0.578、0.852 和 1.376。分离的峰在 210.0nm 处被揭示。方法 B 是薄层分光光度法，其中研究药物的分离是在硅胶板上进行的，使用甲醇-氯仿-庚烷-1-磺酸纳盐（0.4%）（体积比为 7:3:0.1）作为流动相，分离带的扫描在 240.0nm 处进行。氰钴胺、苯磷硫胺和硫辛酸的滞后因子（Rf）值分别为 0.17、0.48 和 0.75。方法的验证遵循 ICH 指南，所应用的方法成功地测定了纯形式和胶囊中的上述药物。结果与制造商的方法进行了统计学比较，未观察到显著差异。
