Evaluation and comparison of expired and extant metformin drug by method validation using UV-VIS spectrophotometry

Abstract

Metformin, a widely used antihyperglycemic drug for the treatment of type 2 diabetes mellitus. The usage of this therapeutic drug has become more common as the frequency of diabetes mellitus metabolic disorder is high world wide especially in India. Improper disposal of the expired drug is creating a huge impact in the environment as well as financial prudence for the country. UV-visible spectrophotometry is one of the simple and accurate method for the apposite validation of drug. Our aim is to evaluate and compare the expired and extant metformin drug by UV-visible spectrophotometry. We observed the absorption maxima at 233nm and the resolution of the analyte peak is highly specific for metformin drug. The calibration curve with different concentration of both expired and extant drugs was found to be linear. The repeated interday and intraday measurements of both the drug at 10 ppm concentration were extremely precise and the percentage recovery was accurate by zero order spectroscopy. The drug solution was stable at different time points and the robustness during all variations was not much affected for both the expired and extant metformin drug. We observed the system suitability is satisfactory and fulfilled all the parameters of method validation. The detection and quantification limit of both the drugs was found to be the lowest concentration about 1ppm as an exact value. Our results conclude that there is no significant variation in all the method validation parameters between the 10 years expired and extant metformin drug. This will be helpful to avoid wastage or disposal of enormous expired metformin drug and to reconsider the extension of expiry date by pharmaceutical companies with proper approval of the organizations.