High-performance thin-layer chromatographic method for determination of erdosteine in pharmaceutical dosage forms

A sensitive, selective, precise, and stability-indicating method for quantitative analysis of erdosteine, in the presence of its degradation products, both as the bulk drug and in a formulation has been established and validated. High-performance thin layer chromatography (HPTLC) on aluminium-backed silica gel 60 F254 plates with toluene–methanol–acetone–ammonia 3.5:3.5:2.5:0.05 (v/v) as mobile phase was followed by densitometric measurement at 254 nm. This system was found to give compact bands for erdosteine (RF 0.45 ± 0.02). The method was validated in accordance with ICH guidelines There was no chromatographic interference from capsule excipients. Erdosteine was subjected to acid and alkaline hydrolysis, oxidation, dry heat, wet heat, and UV degradation. The drug is degraded by acid and alkaline hydrolysis, oxidation, and UV irradiation. The drug was found to be stable under wet and dry heat conditions. Because the method could effectively separate the drug from its degradation products it can be regarded as stability-indicating.