DEVELOPMENT AND VALIDATION OF A SPECTROPHOTOMETRIC METHOD FOR THE ESTIMATION OF ASPIRIN USING FERRIC NITRATE

Aspirin (Acetylsalicylic acid) is a widely used analgesic, antipyretic, and anti-inflammatory drug. It acts by inhibiting cyclooxygenase enzymes and thereby reducing prostaglandin synthesis. A novel, simple, and rapid spectrophotometric method was developed and validated for the estimation of Aspirin in pure form and pharmaceutical formulations using ferric nitrate as a complexing agent. Shimadzu UV-1800 Model UV-VIS double beam spectrophotometer was employed for the study. The method is based on the reaction between the hydrolyzed product of Aspirin (salicylic acid) and ferric nitrate to form a violet-coloured complex exhibiting maximum absorbance at 528 nm within the wavelength range of 300–800 nm. Aspirin linearity was observed over the concentration range 10–120 µg/ml. The linear regression equation was found to be y = 0.0087x – 0.0827 with correlation coefficient R² = 0.9957. The method showed a Limit of Detection (LOD) of 3.5 µg/ml and a Limit of Quantification (LOQ) of 10.6 µg/ml, indicating good sensitivity. The method was validated by precision and accuracy studies and was found suitable for routine analysis of Aspirin content in pharmaceutical preparations.