Effective intestinal absorption of insulin in diabetic rats using enteric coated capsules containing sodium salicylate

Abstract

The absorption of insulin manifested as percent reduction of blood glucose was evaluated after placement of capsules containing 4.6 units of the drug and 20 mg of Sodium salicylate as an absorption promoter in the rate stomach. The capsules were coated with either Eudragit L100 or Eudragit 9100 to deliver insulin in different regions of small intestine of the rats as they are pH dependent. The data obtained after administration of the capsules were compared with that after intraperitoneal injection of 1 U of insulin and ALSO after administration of coated capsules containing insulin alone. The administration of insulin capsules containing sodium salicylate result in a significant (p<0.01) increase of the hypoglycemic effect over the 5 h period of the experiments. They produced the same hypoglycemia effect as I.P. injection at 5 h point. The areas under the % blood glucose reduction curves produced were 363.5, 221.7 and 236.5% h for I.P. injection and capsules coated with Eudragit L100 and Eudragit S100, respectively. The relative bioavailabilities of capsules to I.P. injection were 13.26 and 14.15% for those coated with Eudragit L100 and Eudragit S100, respectively. Enteric coated capsules of insulin alone caused no glucose reduction. © 1995 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted.