Coating Efficiency in Preventing Photolytic Degradation of Two Randomly Selected Brands of Metoprolol Tartrate

Abstract

This research work was carried out to determine whether the film coating is effective to prevent the photolytic degradation of Metoprolol tartrate which is known to have photosensitivity. For this purpose, two randomly selected brands of two different pharmaceutical companies were chosen i.e. Brand A and Brand B. These two brands were exposed to different lighting conditions (normal light, direct sunlight as well as two incandescent lights i.e. 25 watt bulb, 40 watt bulb). Potency tests were performed using UV spectroscopy which showed gradual decline in potency of the tablets under aforesaid lighting conditions and the potency degradations were found 11.48%, 12.92%, 22.62%, 16.87% for Brand A and 14.74%, 14.24%, 10.88%, 18.10% for Brand B under 25 watt bulb, 40 watt bulb, direct sunlight and normal room light respectively. So this study reveals that the both brands containing metoprolol tartrate showed significant light sensitivity even though they are coated and protective opaque packaging is highly recommended for their protection.