How safe and effective is orally delivered insulin for patients with early-stage type 2 diabetes?

This study compared the safety and effectiveness of different doses of an oral insulin capsule formulation (Capsulin™) to patients with early-stage type 2 diabetes (T2D). The data showed that twice-daily, orally administered Capsulin at a dose of 150 international units (IU) was safe and resulted in a significant lowering of glycated hemoglobin (HbA1c; blood glucose control over the past 2-3 months), fasting plasma glucose (FPG) and triglycerides (TG; blood fats) levels.

Patients with T2D are unable to use glucose normally. Medications, exercise, and dietary and lifestyle changes are needed to manage T2D. Medications may or may not include insulin treatments. Injectable insulin can potentially cause blood glucose levels that are too low (hypoglycemia). Oral insulin delivery can offer advantages such as convenience, less pain, and avoidance of hypoglycemia but has not yet been approved for use.

Capsulin™ insulin is an oral insulin capsule that contains a dry white powder (active ingredient) combined with stabilizers. Stabilizers protect the medicine against protein degradation in the stomach and gut. Stabilizers also aid in intestinal absorption. Oral insulin is then taken up by the liver followed by the bloodstream. Hypoglycemia is unlikely to develop. There is a need to investigate the potential use of Capsulin™ in the treatment of early-stage T2D.

This study included 100 patients with T2D. All patients received metformin (1000 mg to 2500 mg daily) as antidiabetic therapy before and during the study. Patients were randomized and placed into three treatment groups. Group 1 received 75 IU (2.5 mg) of Capsulin™ twice daily. Group 2 was given 150 IU (5 mg) of Capsulin™ twice daily. Group 3 received 300 IU (10 mg) of Capsulin™ twice daily. The capsules were taken an hour before breakfast and dinner. Treatments were given for 12 weeks. Changes from the beginning of the study were determined for HbA1c and FPG. Patients were followed for one month after the study.

HbA1c levels significantly decreased from the beginning of the study for Groups 2 (by 0.52%) and 3 (by 0.42%). FPG levels were significantly lowered in Group 2. TG decreased by 20% in Group 2. There were no episodes of hypoglycemia during the study.

The study concluded that 150 IU of oral Capsulin™, twice daily, was safe and significantly lowered HbA1c, FPG, and TG levels from baseline in patients with early-stage T2D.

The study design did not include a placebo group for comparison. This study had a small number of participants and a short duration. Larger studies are needed to confirm these results.