Stable concentrated insulin preparations for pulmonary delivery

Abstract From the Canadian patent

Concentrated aqueous insulin formulations of high physical and chemical stability are disclosed. The formulations are suitable for pulmonary delivery. The object has been accomplished by providing an insulin formulation in which the concentration of chloride is kept below 50 mM and in which the , concentration of other anions such as phosphate is minimised. The aqueous insulin formulation comprises 3 to 20 mM of human insulin or an analogue or a derivative thereof, less than 50 mM of chloride less than 10 mM of any anions , other than chloride and acetate 2 to 5 Zn2+ ions per six molecules of insulin, and at least 3 phenolic molecules per six molecules of insulin.