Self-dissolving micropile array tips for percutaneous administration of insulin.

Two kinds of insulin were loaded into self-dissolving micropile array tip (following tip). Fully-loaded tip (f-tip) and partially-loaded tip (p-tip) were prepared using chondroitin sulfate for the percutaneous administration of insulin. One hundred micropiles were constructed on a 1.0 x 1.0 cm tip. The mean length of the micropile in a tip were 483.4 +/- 4.7 mum for the f-tip and 492.6 +/- 2.4 mum for the p-tip. The insulin content of the p-tip was 28.5% of that of the f-tip. The pharmacological efficiency of insulin loaded tip was evaluated in rat experiments by measuring their hypoglycemic effects. The maximum hypoglycemic effect of insulin was observed at 1.7 +/- 0.2 h for the f-tip and 1.5 +/- 0.2 h for the p-tip. Good dose-dependency was observed for the plasma glucose level vs. time curves. These results suggest the usefulness of p-tip as a percutaneous DDS of insulin.