Novel route of insulin delivery using an implant-mediated drug delivery system

Patients with diabetes mellitus (DM) frequently require multiple painful injections of insulin to manage their blood glucose level. A newly introduced, modified titanium implant, the implant-mediated drug delivery system (IMDDS), has the advantage of sustained, needle-free drug delivery. We evaluated the feasibility of the IMDDS as an alternative route of insulin delivery in an alloxan-induced rabbit DM model. Among a total of 30 rabbits with IMDDSs, 25 survived the induction and had a blood glucose level (BGL) higher than 300 mg/dl. The animals were divided into two groups: 13 in the test group to which insulin was administered via the IMDDS and 12 in the untreated control group. The BGL was monitored and measured at 0, 2, 4, 6, 8, 12, and 24 hours on the first day and every 12 hours thereafter for a total of 2 weeks. Marked hypoglycemic effects of insulin in the test rabbits were detected from the 2-h time point, and the mean BGL fell below the normal range from 12 h after insulin administration via the IMDDS. The effects lasted the entire 2-week period. Control rabbits did not show a pronounced decrease in BGL except for three animals who exhibited spontaneous recovery. The mean body weight of the test group was significantly higher than that of the control group at the end of the observation period. Although this implant requires several improvements, the IMDDS exhibited promise as an alternative route of insulin delivery with the advantages of being a sustained, needle-free insulin delivery system.