Gastric emptying in relation to drug absorption

Summary 1. Test meals were given to healthy subjects, and the rate of gastric emptying was assessed from the volumes of the gastric contents recoverable after different periods.2. With test meals of 500 ml. containing a mixture of sodium citrate, sodium bicarbonate, and monocalcium phosphate, the rate of gastric emptying was more rapid than that of water and was largely independent of the concentration of the salts in the meal.3. Neither effervescence of the solutions nor the presence of acetyl-salicylic acid has any notable effect on gastric emptying.4. The influence of the volume of an ingested solution on gastric emptying, based on previous experiments, is outlined.5. These data are considered in relation to the volume and composition of a vehicle for drugs which are intended to reach the small intestine soon after they are taken.The author is grateful to the subjects for their continued co-operation. The dummy tablets, and the active tablets, which are available as Alka Seltzer, were kindly supplied by Miles Laboratories, Inc., Elkhart, Ind.