Reproducibility Study on the Efficiency of Film Coating on Preventing Photolytic Degradation of Betaloc® (Metoprolol Tartrate) Tablets

Abstract

This research work was aimed to evaluate the reproducibility of the data in a study that was previously done in order to determine whether the film coating is effective to prevent the photolytic degradation of Metoprolol Tartrate which is a photosensitive drug. For this purpose, Betaloc® of Drug International Limited was chosen which was exposed in various lighting conditions (normal room light, 25watt bulb, 40watt bulb & sunlight). A group of tablet was kept in dark as control to compare the result. Physical parameters and potency of the tablets were determined. Color change, thickness, hardness, and weight variation were measured according to USP and little or no significant change was found. The standard deviation of the thickness, hardness and weight variation was ±0.0026 cm, ±0.4300 kg & ±0.0025gm respectively. Potency test was performed by UV spectroscopy at 221.5 nm wavelength showed gradual decline in potency of the tablet. In various lighting condition like 25watt bulb, 40watt bulb, direct sunlight and normal room light, the percent variation in potency was 11.48%, 12.92%, 22.62% and 16.87% respectively. So this study reveals that the Betaloc® containing metoprolol tartrate is light sensitive and coating alone is not sufficient to protect the drug from light. So that protective opaque package should be used thus light cannot pass through the package.