Salicylic acid and its concern have long been used for the management of pain, fever, and inflammation. Of this group, acetyl-salicylic acid, or aspirin (ASA) has proved to be the most potent in each case. Although hydrolysis, the first step in biotransformation of aspirin takes place very rapidly, many workers feel that the greater effectiveness is due to a unique action of the intact molecule; however, others disagree. In this study, the effects of aspirin and in vitro were compared in order to obtain a greater amount of information relating to the problem.