Formulation of Insulin Containing Niosomes and the Effect of Their Oral Administration on Blood Glucose in Streptozotocin-induced Diabetic rats

Multilamellar vesicles (noisome) of polyoxyethylene alkyl ether surfactants (Brij ۵۲, ۷۲, ۷۶ and ۹۲) were prepared using classic film hydration method. Vesicle formation ability of the surfactants was assessed in presence or absence of cholesterol. All used surfactants formed vesicles in the absence of cholesterol. Recombinant human insulin was used as a model protein drug to investigate encapsulation efficiency and release characteristics of the vesicles. The amount of insulin released in simulated intestinal fluid (SIF) and simulated gastric fluid (SGF) from Brij ۹۲ vesicles was lower than the other ones. This vesicles also showed the highest protection of insulin against proteolytic enzymes, pepsin and trypsin. Diabetes was induced by IP injection of streptozotocin (۶۵ mg/kg) in male wistar rats. Animals treated with oral niosome (Brij ۵۲ and ۹۲)-encapsulated insulin (۱۰۰ IU/kg) showed decreased levels of blood glucose and elevation of serum insulin, which in the case of Brij ۹۲ niosomes the hypoglycemic effect was significant (P< ۰. ۰۵).

Keywords:

insulin , Oral drug delivery , Polyoxyethylene alkyl ethers , Niosome