Nasal administration of insulin using bioadhesive microspheres as a delivery system

Abstract

The use of the bioadhesive microsphere system for the intranasal delivery of insulin was investigated in sheep. The effect of combining the above system with lysophosphatidylcholine, as a biological absorption enhancer, was also assessed. For comparison, insulin was also administered by the intravenous and subcutaneous routes. The plasma glucose and insulin levels were determined by a glucose oxidase method and a radioimmunoassay, respectively. The bioadhesive system produced large and significant changes in the plasma insulin and glucose levels. The relative bioavailability (± standard error of measurement) of insulin administered with the microsphere system alone was found to be 10.7% (±2.6) and that of insulin administered with the microsphere /enhancer system to be 31.5% (±6.5).