Safila Naveed, Areesha Shafiq, Madiha Khan, Madiha Jamal, Hira Zafar, Hira Hashim and Lubna Urooj
There are several different brands available for metformin as it is the most prescribed oral antihyperglycemic agent that is used for Type-II Diabetes mellitus. The objective of this study develop the degradation studies of different brands of metformin HCL500 mg. Metformin was subjected to different stress conditions as per (ICH) International Conference on Harmonization guidelines. A UV spectroscopic method was developed for analysis of the drug in the presence of the degradation products. Methanol and distilled water were used as solvents. The amount of degraded drug was calculated by taking absorbance at 237 nm. According to the assay limit of USP specified that the content should not be less than 95% and not more than 105% of labelled amount. Brand A, C and E are degraded after heating. Brand A,B,C, and D are degraded by UV light exposure .On basic pH brand A, and C showed degradation after the addition of 0.1 N NaOH while other brands does not degraded as base has no impact on metformin concentration and the original pH of metformin HCL was 6.68 before addition of acid and base. On addition of 0.1 N HCL all brands showed heavy degradation. After 15 days the time affects and degrades the metformin concentration of all brands. The method was found to be simple and less time consuming and cost effective. Hence this method can be successfully used to study stress degradation behavior of metformin in small industry where high end instruments are not available.