Purpose. Good glycaemic control is essential to minimize the risk for diabetes-induced complications. Also, compliance is likely to be higher if the procedure is simple and painless. This study was designed to validate painless intradermal delivery via a patch-like microneedle array.
Materials and Methods. Diabetes was induced by an intravenous injection of streptozotocin (50 mg/kg bw) in adult male Sprague Dawley rats. Plasma insulin and blood glucose were measured before, during and after subcutaneous or intradermal (microneedles) infusion of insulin (0.2 IU/h) under Inactin-anaesthesia.
Results. Before insulin administration, all animals displayed a pronounced hyperglycaemia (19 +/- 1 mM; 359 mg/dl). Administration of insulin resulted in a reduced plasma glucose independently of administration route (subcutaneous 7.5 +/- 4.2, n=9, and intradermal 11 +/- 1.8, n=9 after 240 min), but with less errors of the mean in the intradermal group. In the intradermal group, plasma insulin was increased in all latter measurements (72 +/- 22, 81 +/- 34, and 87 +/- 20 mu IU/ml), as compared to the first measurement (26 +/- 13). In the subcutaneous group, plasma insulin was elevated during the last measurement (to 154 +/- 3.5 mu IU/ml from 21 +/- 18).
Conclusion. This study presents a novel possibility of insulin delivery that is controllable and requires minimal training. This treatment strategy could improve compliance, and thus be beneficial for patients' glycaemic control.
2007. Vol. 24, no 7, 1381-1388 p.
diabetes; insulin lispro; intradermal; microneedles; rats; transdermal; DIABETES-MELLITUS; TRANSDERMAL DELIVERY; HOLLOW MICRONEEDLES; IN-VITRO; INHALED INSULIN; RAT DERMIS; INJECTION; TYPE-1; SKIN; STREPTOZOTOCIN