Rapid Quantitative Simultaneous Determination of Vitamin A and Vitamin D in a Skin Ointment Pharmaceutical Formulation Based on Net Analyte Signal and Partial Least Squares using the UV Spectrophotometric Method

Objective The aim of this study was to propose an easy, fast, and precise method, which can be satisfactorily applied to the simultaneous determination of the drugs in pharmaceutical dosage forms instead of the high-performance liquid chromatography (HPLC) method. Methods Complicated and costly instruments, as well as spending a lot of time for analysis are the limitations of the chromatography method. Hence, UV spectrophotometric technique based on net analyte signal (NAS) and partial least squares (PLS) was proposed and validated for the simultaneous determination of vitamin A and vitamin D in binary mixtures and commercial skin ointment. The chromatographic technique was implemented to compare with the proposed approach for the simultaneous analysis of drugs. Results The NAS method was able to determine vitamin A and vitamin D in the concentration range of 1-7 and 2-13 mu g mL(-1) at lambda(max)= 323 and lambda(max)= 261, respectively. The limit of detection (LOD) and limit of quantification (LOQ) related to the NAS method were found to be 0.092, 0.053 mu g/mL and 0.214, 0.170 mu g/mL for vitamin A and vitamin D, respectively. The root mean square error (RMSE) of the test series was 0.0607 and 0.0547 for vitamins A and D, respectively. Recoveries by the PLS method were found in the range of 99.98%-100.49% and 99.57%-100.88% for vitamins A and D, respectively. The results obtained from the NAS and PLS procedures were statistically compared with the reference method (HPLC) via analysis of variance (ANOVA) test, where no significant difference was observed. Conclusion The spectrophotometry along with NAS and PLS methods are proper, rapid, and economic for the determination of pharmaceutical components in quality control laboratories.