Absorption of acetylsalicylic acid from unbuffered and buffered gastric contents

Test meals of 200 ml containing acetylsalicylic acid or buffered acetylsalicylate were given to 19 healthy subjects. Studies were made of the rate of gastric emptying and the gastric absorption of acetylsalicylic acid. It was found that the buffered acetylsalicylate test meals (pH 7.0) were emptied more rapidly from the stomach than test meals containing unbuffered (pH 2.8) acetylsalicylic acid. After 10 min, considering the means of amounts of aspirin absorbed, there was at least 10 times less absorbed from the buffered solution. No bleeding into the gastric contents was observed in response to any test meal.Supported by Miles Laboratories, 1127 Myrtle St, Elkhart, Ind 46514.The authors are grateful to the subjects for their cooperation, and to Miss J. Boram, and Miss D. Porter for technical assistance and are indebted to Drs. W. E. Goldstein and C. L. Sutula of Ames Company Division, Miles Laboratories Inc. for the computation underlying the maximal and minimal values of Table 2. An account of their methods is being prepared for publication.