Investigation of the Stability of Acetylsalicylic Acid at Different Temperatures

Abstract

This study investigated the stability of acetylsalicylic acid (ASA) in aqueous citric acid solutions at various temperatures (21°C, 37°C, 45°C, and 60°C). The degradation of ASA was monitored using a titrimetric method to quantify its hydrolysis product, salicylic acid. Kinetic analysis based on the Arrhenius equation was performed to evaluate the stability profile of ASA under different storage conditions. The findings indicate that hydrolysis occurs even at room temperature, leading to a significant decrease in ASA concentration over time. The activation energy was calculated as 7.48 kcal, suggesting a rapid degradation process. The results highlight the instability of ASA in aqueous formulations, making it unsuitable for liquid dosage forms. To improve stability and prevent hydrolysis, alternative solvents such as propylene glycol and polyethylene glycol may be used instead of water. Additionally, microencapsulation techniques can offer a protective barrier against degradation, ensuring extended shelf life and improved pharmaceutical efficacy. These findings provide crucial insights for the formulation of stable liquid aspirin preparations and emphasize the necessity of selecting appropriate solvents and excipients in pharmaceutical development.

Keywords

• Acetylsalicylic acid
• Stability
• Hydrolysis
• Citric acid
• Arrhenius equation
• Pharmaceutical formulation

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