ABSTRACT
The objective of this study was to assess the clinical efficacy of a single dose of insulin [100 IU] incorporated with a group of additives in enteric-coated, chitosan-coated capsules through its glucose lowering effect over a period of 12 hours. The capsules were administered orally to type-2 diabetic patients. The results were compared to those of oral administration of capsules of the same coating containing only insulin [100 IU] without additives, S.C. insulin injection [average dose 18 IU] and oral placebo. Ten patients with type-2 diabetes were enrolled in this blind, placebo-controlled, four-way crossover study. It was found that, capsules containing, only insulin resulted in a slight decrease in the mean blood glucose levels of the 10 patients compared to control especially in the period from 6 to 12 hours following administration. On the other hand, capsules containing insulin with additives showed a remarkable lowering of the blood glucose levels. Their effect started 3 hours following administration and sustained to the end of the experiment [12 h]. During the first 4 hours following administration was the reduction resulting from S.C. insulin was significantly higher than that produced by capsules containing insulin with additives. In the period from 4-7 hours, the effect of the capsules was comparable to that of S.C. insulin [no significant difference]. Beyond that [7-12 hours], there was a highly significant difference in favor of capsules. The relative bioavailability obtained by capsules containing only insulin was 3.43%, while that obtained by capsules containing insulin with additives was 18.54%