Evaluation of the pharmacodynamic activity of insulin from bilosomal formulation

In this study, bilosome as a drug delivery system for insulin was studied. Two bilosomal preparations were formulated and assessed. One was prepared using a lipid extract from Soya beans seed (SBE), Palmitic acid (PA) and cholesterol (CH ) in the ratio of 0.25:1:1 w/w designated as BI while the other (BII) contained PA and CH as the lipid entity at the ratio of 1:1 w/w. Each of the preparations contained 0.5% of sodium deoxycholate (SDC) and soluble insulin. BI was given orally only, while BII was administered subcutaneously, intraperitoneally and orally to different groups of streptozotocin-induced diabetic male rats, and the blood glucose levels were measured at predetermined time intervals. The results of the studies showed that oral administration of BI and BII produced blood glucose reduction, which could mimick endogenous release of insulin with prolonged activity, although, less blood sugar lowering compared with parental administration. BI (oral I) containing SBE had greater reduction of blood glucose than BII (oral II) ,showing that SBE increased the bioavailability of insulin. Bilosomal insulin formulation could provide a good oral delivery system for insulin that would affect the entero-insular axis similar to endogenous insulin.