Abstract

It is very important to have simple but fast analytical procedures to determine the active ingredient concentrations in drug substances as the significant deviation from the labelled amount might negatively affect the patients. The goal of this study is to develop a simple and accurate method to determine the active ingredient concentrations of metformin hydrochloride (type II diabetes) and atorvastatin calcium (hypercholesterolemia) using a simple ultraviolet photo spectroscopy (UV). The method has been developed according to the International Conference on Harmonization (ICH) guidelines and validated using the acceptance criteria of linearity, range, accuracy, precision, limit of detection (LOD), limit of quantitation (LOQ), and stability. From the UV-Vis spectra, the wavelength of maximum absorbance (λmax) values of metformin hydrochloride and atorvastatin calcium tablets were measured and used for the rest of the study. A five-point calibration curve was obtained within a concentration range from 2-10 ppm with a correlation coefficient (R2) of 0.999 for metformin hydrochloride and 5-15 ppm concentration range with an R2 value of 0.998 for atorvastatin calcium. The accuracy was tested with the spike recovery method which showed the mean recoveries occur from 92.14% to 95.04% for metformin hydrochloride and 90.10% to 102.90% for atorvastatin calcium, respectively. Test sample analysis was carried out by using different brands purchased from various places in Sri Lanka, manufactured in different countries. The developed method resulted that the actual concentration of the active ingredients of metformin hydrochloride ranged from 382.70 to 454.19 mg per 500 mg tablet while 9.00 to 9.88 mg per 10 mg tablet for atorvastatin calcium. Since the calibration plot can be prepared using premade standard solutions stored at room temperature or refrigerated conditions, it can be concluded that the developed analytical procedure can be used for quantitative analysis of the active compound for the selected drugs. Since standard samples have proven stability of seven days, no need of repeat preparation of calibration plots for each analysis.

Keywords: Method development; Spectroscopy; Metformin hydrochloride; Atorvastatin calcium