Method Development and Stress Degradation Profile of 5-Benzyl-1,3,4-Oxadiazole-2-Thiol Studied by UV Spectroscopy

Abstract

Considering the pharmacological activities of 5-benzyl-1,3,4-oxadiazole-2-thiol (OXPA), the present study aimed to develop and validate a UV-spectroscopic method according to the ICH guidelines to be used to study degradation profile of the compound. The method was developed at 263 nm, the wavelength giving maximum absorbance. Linearity of the method was evaluated by analyzing a series of standard solutions. Then, recovery, accuracy and sensitivity were determined. The compound was subjected to a number of stress conditions to determine it in the presence of degradants (specificity). The proposed method showed linearity in a concentration range (0.33 - 40.0 μg/mL) with correlation coefficient (R²) = 0.998. The recovery was within 100.63 – 102.46%, intraday and inter-day accuracy were found to be 99.10 – 102.46% with relative standard deviation less than 2%, and the LOD and LOQ were found to be 0.099 and 0.330 μg/mL, respectively. The OXPA was degraded with the passage of time under acidic conditions and oxidized completely in 35% H₂O₂, whereas the degradation was 58.47% in 3% H₂O₂. Dry heat (80°C) exposure for 48 h resulted in 1.09% degradation, whereas UV exposure resulted in complete loss of the compound. These results indicate that the method is simple, sensitive, accurate and specific, hence may be used to carry out quantitative work on OXPA.