Oral spray insulin in treatment of type 2 diabetes: A comparison of efficacy of the oral spray insulin (Oralin) with subcutaneous (SC) insulin injection, a proof of concept study

Objective. Proof-of-concept study of evaluation of metabolic effect of novel oral spray insulin (Oralin) formulation at breakfast time in subjects with type 2 diabetes on multiple daily injections. Research design and methods. This was an open-label, crossover, randomized study in (n = 23) subjects with type 2 diabetes on multiple daily injections. Subjects received each treatment, in random order, 3 to 7 days apart - a daily dose of SC injection (0.1 u/kg) on one occasion and Oralin spray (100 u) at time 0 min on another occasion. Subjects were given a standard breakfast containing 360 cal (Sustacal liquid meal) 10 min after the dose. Blood samples were taken at regular intervals to measure glucose, insulin, and C-peptide. Results. The 30- and 60-min postprandial glucose levels were significantly lowered with Oralin versus that with the injection treatment (146 ± 5 mg/dL Oralin vs 184 ± 7 mg/dL injection at 30 min and 192 ± 6 mg/dL Oralin vs 236 ± 9 mg/dL injection, p < 0.003 at 60 min). The rise in serum insulin levels was significantly higher (Cmax = 98 ± 6 uU/mL for Oralin at 30 min vs 65 ± 3 uU/ml injection, p < 0.001). The reduction in C-peptide was greater in Oralin during the first 60 min (1.38 ± 0.21 ng/mL Oralin vs 1.75 ± 0.38 ng/mL injection, p < 0.001). Conclusions. This proof-of-concept study results demonstrated that Oralin could be used as meal insulin in place of mealtime-insulin injections in subjects with type 2 diabetes to regulate the postprandial glucose levels.