Influence of Certain Additives on the Diffusion Rate of Aspirin, Salicylamide and Phenacetin Through the Rat's Ileum

The diffusion rate of aspirin, salicylamide and phenacetin through the rat's ileum was found to be concentration dependent. The presence of glucoseamine hydrochloride decreased the amount diffused from each drug. The higher diffusion rate of aspirin was happened in presence of 0.01% w/v Myrj 59, followed by Brij 58 and then cetrimide. While that of salicylamide increased in presence of 0.01% w/v Tween 80. The more convenient increase in the diffusion rate of phenacetin produced in presence of 0.01% w/v Tween 20 and 0.3% w/v sodium lauryl sulfate. The other tested surfactants either reduced the amounts of drugs diffused or produced insignificant effect. With regard to the effect of aliphatic acids-drugs solid dispersions, tartaric acid increased the diffusion rate of aspirin; citric, tar taric and succinic acids as well as PEG 4000 increased the diffusion rate of salicylamide while, succinic acid increased the diffusion rate of phenacetin through the rat's ileum.