Presence of Acetylsalicylic Acid in Plasma Following Oral Ingestion of Aspirin

Abstract

The absorption and hydrolysis of aspirin was examined under various experimental conditions. Aspirin appears to be absorbed intact from the gastrointestinal tract. High concentrations of acetyl-salicylate in the plasma can be demonstrated following the oral inges-tion of soluble but not insoluble aspirin preparations. This is correlated with the increased rate of absorption of the soluble products. There appears to be a rapid hydrolysis of acetylsalicylate in vivo and it is suggested that the principal site of this hydrolysis is the tissues. Direct evidence for the hydrolysis of acetylsalicylate to salicylate by the liver of the dog was demonstrated.