Systemic absorption of insulin delivered topically to the rat eye.

Academic Article

Abstract

  • Insulin administration in eye drops containing 1% saponin caused a rapid and reproducible reduction in blood levels of D-glucose in anesthetized rats; insulin eye drops lacking saponin were ineffective. Systemic insulin absorption also was observed when Brij 78 or BL-9 was substituted for saponin in eye drops containing insulin. Nonanesthetized rats displayed lower initial D-glucose levels than anesthetized rats, and little hypoglycemic response to insulin eye drops could be observed, suggesting that counter-regulatory hormones could effectively counterbalance the influence of exogenous insulin on glycemic control. Streptozotocin-diabetic rats displayed elevated blood D-glucose values (greater than 400 mg/dl), and these values were decreased to 100-200 mg/dl after the administration of insulin in eye drop solutions containing saponin. The site of insulin absorption appears to be the nasolacrimal drainage system of the rat because administration of a solution containing insulin plus saponin directly into the punctum caused a rapid, significant decrease in blood D-glucose levels. The observation that insulin could be absorbed from the rat eye is consistent with the possibility that insulin eye drops containing an absorption-enhancing surfactant agent could be of potential benefit in the treatment of diabetes mellitus in humans.
  • Keywords

  • Absorption, Administration, Topical, Animals, Blood Glucose, Diabetes Mellitus, Experimental, Disease Models, Animal, Drug Carriers, Eye, Insulin, Male, Nasolacrimal Duct, Ophthalmic Solutions, Radiography, Rats, Rats, Inbred Strains, Streptozocin
  • Author List

  • Pillion DJ; Bartlett JD; Meezan E; Yang M; Crain RJ; Grizzle WE
  • Start Page

  • 3021
  • End Page

  • 3027
  • Volume

  • 32
  • Issue

  • 12