Hydrolysis of Aspirin in Different Solvent Systems-The rate ofhydrolysis of aspirin was followed by direct measurement of the amountof intact aspirin remaining as a function of time. The hydrolysis of aspirinwas found to follow apparent first-order kinetics in all solvent systemsstudied. A minimum of four and maximum of six replicate kinetic runswere conducted for each of the solvent systems used. The concentration-time data were fitted to the linear regression equation for pseudofirst-order kinetics.