Biokinetics of buccal spray insulin in patients with type 1 diabetes

Objective To evaluate the metabolic effect of buccal spray insulin compared with subcutaneous regular insulin in patients with type 1 diabetes. Research Design and Methods This study compared plasma glucose, insulin, and C-peptide levels in 18 patients with type 1 diabetes treated with subcutaneous regular or buccal spray insulin on 2 consecutive mornings. On day 1, patients were treated with their usual subcutaneous regular insulin regimens. On day 2, patients received buccal spray insulin. In the morning of both days 1 and 2, patients received a standard meal of 630 kJ. No intermediate or long-acting insulin was administered to patients on the morning of the test. Blood samples were collected for up to 4 hours for biokinetic analysis. In a subset of 3 patients, premeal buccal spray insulin was administered for 2 entire consecutive days. In these patients, glucose levels were monitored using the glucose sensor monitoring system. Results Overall, there were no statistically significant differences in glucose, insulin, or C-peptide levels measured after administration of subcutaneous vs buccal spray insulin. However, at 90 and 120 minutes after subcutaneous regular insulin administration, significantly higher insulin levels and more prolonged hypoglycemic effect were detected compared with buccal spray insulin administration. In the 3 patients who received 1 day of regular and 2 entire days of buccal spray insulin, no significant differences were observed in glucose levels during the 3 days of glucose sensor monitoring. Conclusions Insulin administered via the buccal spray formulation is as effective as the subcutaneous route in lowering blood glucose levels.