Abstract
The present study describes stress degradation studies on a biomarker, trigonelline following the International Conference on Harmonization (ICH) guidelines under different stress conditions and establishment of a stability‐indicating HPTLC assay method. Analysis of trigonelline was performed on TLC aluminium plates precoated with silica gel 60F‐254 and mobile phase consisting of n‐propanol‐methanol‐water (4:1:4 v/v/v). Spectrodensitometric scanning was carried out in absorbance mode at 269 nm for trigonelline (Rf=0.46±0.02). Trigonelline was subjected to acid and alkali hydrolysis, oxidation, dry heat, wet heat treatment, and photodegradation. Statistical analysis proves that the developed HPTLC method is reproducible and selective. As the method could effectively separate the drug from its degradation products, it can be employed as a stability‐indicating one. Moreover, the method was utilized to investigate the kinetics of the acidic and alkaline degradation processes at different temperatures and to study degradation in constant ionic strength buffer solutions within the pH range 1–11.