EFFECTS OF ORALLY-ADMINISTERED INSULIN NANOCAPSULES IN NORMAL AND DIABETIC DOGS

Polyalkylcyanoacrylate nanocapsules used as a drug carrier for insulin have been shown to preserve the therapeutic effect of insulin when ad ministered orally to rats. This study was undertaken to investigate th e effects of oral insulin nanocapsules in normal and alloxan induced d iabetic dogs. In normal dogs, a single oral administration of 100 U/kg insulin nanocapsules decreased hyperglycemia induced by an i.v. gluco se overload. This effect was maximal after 9 clays and had disappeared at day 21. Moreover, fasted glycemia remained unchanged. In diabetic dogs, glycosuria was accompanied by elevated blood glucose as well as plasma glucagon and somatostatin concentrations. A single oral adminis tration of 100 U/kg insulin nanocapsules reduced significantly glycosu ria and postprandial glycemia, glucagonemia and somatostatinemia from the 2nd day and lasted up to the 6th or 8th clay depending on the para meter studied; these reductions were weaker in the fasting state. Our results indicate that orally administered insulin nanocapsules induce several beneficial persistent effects in both normal and diabetic dogs . Thus this new form of insulin administration could be of interest in the treatment of diabetes.