Novel microneedle patches for active insulin delivery are efficient in maintaining glycaemic control: an initial comparison with subcutaneous administration.
OBJECTIVE
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.


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 microIU/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 microIU/ml from 21 +/- 18).


CONCLUSIONS
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.
Nordquist
Lina
L
Department of Medical Cell Biology, Division of Integrative Physiology, Biomedical Centre, Uppsala University, Uppsala, Sweden. Lina.Nordquist@medcellbiol.uu.se
Roxhed
Niclas
N
Griss
Patrick
P
Stemme
Göran
G
D000279:Administration, Cutaneous; D000818:Animals; D001786:Blood Glucose / Q000187:drug effects*; D003692:Delayed-Action Preparations; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000188:drug therapy*; D016503:Drug Delivery Systems / Q000295:instrumentation*; D004867:Equipment Design; D007004:Hypoglycemic Agents / Q000008:administration & dosage* / Q000097:blood / Q000627:therapeutic use; D007262:Infusions, Intravenous; D007271:Injections, Intradermal / Q000295:instrumentation; D007279:Injections, Subcutaneous; D007328:Insulin / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood / Q000627:therapeutic use; D061268:Insulin Lispro; D008297:Male; D008845:Microinjections / Q000295:instrumentation*; D009339:Needles; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results
D001786:Blood Glucose; D003692:Delayed-Action Preparations; D007004:Hypoglycemic Agents; D007328:Insulin; D061268:Insulin Lispro