Buccal spray insulin (Oralgen) for type 2 diabetes: what evidence?

The achievement of a good glycemic control and, in particular, the management of postprandial hyperglycemia represent the most significant treatment target for the management of diabetes. Multiple daily insulin injections are often still required to gain the treatment goals. Since the noncompliance with injected insulin therapy causes a slowdown in the process of glycemic compensation, novel non-injectable insulin formulations have been developed. Oral spray insulin (Oralgen) is a tasteless liquid formulation that provides insulin absorption via buccal mucosa.

To elucidate the current status of Oralgen in type 2 diabetes patients, studies of pharmacodynamic and pharmacokinetic and clinical trials are reviewed.

The 'psychological insulin resistance,' represented by the reluctance of both patients and health-care professionals to initiate insulin therapy, could be won by alternative routes of insulin administration, improving patients' compliance. In particular, Oralgen seems to be suitable to manage the postprandial hyperglycemia without hypoglycemic risk, although no comparative studies with rapid-acting insulin analogs and no randomized controlled trials in large cohort subjects with type 2 diabetes are available to date.