Comparison of pharmacokinetic and pharmacodynamic properties of single-dose oral insulin spray and subcutaneous insulin injection in healthy subjects using the euglycemic clamp technique

Background: Oral insulin spray is a new, noninjectable method of insulin delivery This system delivers an aerosol of uniform-sized droplets containing regular human insulin at a high velocity into the oropharyngeal cavity for local transmucosal absorption. Objective: The purpose of this study was to compare the pharmacokinetic and pharmacodynamic properties of single-dose oral insulin spray and SC insulin injection in healthy subjects. Methods: Healthy male volunteers aged 21 to 25 years participated in this open-label study conducted at the Diabetes Unit, Hadassah-Hebrew University Hospital, Jerusalem, Israel. Subjects presented at 2 visits separated by 7 to 14 days. At both visits, the euglycemic clamp technique was used to maintain a constant blood glucose level. At one visit, subjects received regular human insulin 0.1 U/kg by SC injection. At the other visit, subjects received 15 puffs (150 U) of oral insulin spray The pharmacokinetic (insulin absorption) and pharmacodynamic (glucose uptake) properties of the drugs were evaluated using blood analyses over the subsequent 360 minutes. Results: Six volunteers were enrolled (mean [SD] age, 22.8 [1.2] years; mean [SD] body mass index, 23.2 [2.2] kg/m(2)). The mean (SD) baseline-corrected C-max was significantly higher with oral insulin spray compared with S C insulin (54.0 [ 20.3] vs 30.8 [6.1] muU/mL; P = 0.028). Mean (SD) T-max was significantly shorter with oral insulin spray compared with SC insulin (23.3 [5.2] vs 83.3 [42.2] minutes; P = 0.027). The mean (SD) time to maximal metabolic effect (maximum glucose infusion rate [GIR(max)]) (44.2 [8.6] vs 100.0 [35.6] minutes) and late time to half-maximal effect (101.0 [41.0] vs 257.2 [27.8] minutes) were shorter with oral insulin spray compared with SC insulin (both, P = 0.028). The baseline-corrected GIR(max) (6.8 [3.3] vs 6.2 [2.3] mg/kg(.)min) and glucose consumption (396.7 [178.0] vs 432.1 [226.0] mg/kg) during the 120 minutes after study drug administration were comparable between oral and SC insulin, respectively. Conclusions: In this study in a small, selected population of healthy male subjects under euglycemic conditions, oral insulin spray was associated with a higher Cmax, shorter Tmax, and faster time to peak glucose uptake compared with SC insulin. The short T-max and the 120-minute duration of effect of oral insulin spray suggest it may be a promising alternative for fulfilling meal-related insulin requirements in persons with diabetes. (Clin Ther. 2004;26:2084-2091) Copyright (C) 2004 Excerpta Medica, Inc.