The inability of subcutaneous (sc) insulin to effectively, safely and painlessly control postprandial glucose levels has encouraged the exploration of alternate methods of insulin delivery. Recently, a novel drug delivery system, based on a unique liquid aerosol formulation, has been developed. This system allows precise insulin dose delivery via a simple, cosmetically acceptable metered dose inhaler in the form of fine aerosolized droplets directed into the mouth. The system introduces a fine-particle aerosol at high velocity into the patient's breath; the mouth deposition is dramatically increased compared with conventional technology. This oral aerosol formulation is rapidly absorbed through the buccal mucosal lining and in the oropharynx regions, and it provides the plasma insulin levels necessary to control postprandial glucose rise in diabetic patients. This novel, pain-free, oral insulin formulation has a critical series of attributes: rapid absorption, a simple (user-friendly) administration technique, precise dosing control (comparable to injection within one unit), and bolus delivery of drug. This review describes the recent results of clinical studies (in type 1 and type 2 diabetic patients) by comparing the efficacy of Oralin (oral insulin spray) versus sc injected insulin and placebo arms. A simplified means for prandial insulin delivery, such as that offered by this technique, will significantly reduce the incidence of key complications by allowing increased patient compliance for consistent drug administration in order to regulate patients' blood glucose levels.
Copyright 2002 John Wiley & Sons, Ltd.