Quantitative determination of albendazole forced degradation percentages by densitometric thin layer chromatographic method

Simple densitometric thin layer chromatographic method has been applied in this study to proceed forced degradation test of albendazole by subjecting drug to acidic, alkaline, oxidative, thermal, and photolytic conditions, and determine the degradation percentages of albendazole in these conditions after 1, 2, 4, and 6 hrs. Two different mobile phases have been used in this study to separate degradation products. chloroform: diethyl ether: glacial acetic acid (75: 12.5: 12.5, v/v) as mobile phase 1, and dichloromethane: methanol (90: 10, v/v) as mobile phase 2. Silica gel GF-254 TLC-plates were used, and densitometric Area under curve (AUC) and AUC percentages were measured. Densitometric measurements showed that albendazole is unstable in all stress conditions but in different percentages, with the least susceptibility have been reported with acid condition (just 6.13% of drug lost after 6 hrs. of incubation). Acidic medium caused reversible degradation with homogeneity in the structures of degradation products, Unlike Alkaline medium which showed heterogeneity in structures detected through the change in the number and Rf-values of degradation spots against time. Both mobile phases were suitable for detecting albendazole degradation percentages under different conditions, as quantitative measurements were closely similar for the two phases, but mobile phase 1 was better to differentiate base-induced degradation products and mobile phase 2 was better for photolytic-induced degradation products.