Insulin pumps and insulin quality--requirements and problems.

In developing insulin solution suitable for delivery devices the chemical and biological stability, as well as the physical stability, must be taken into consideration. Addition of certain mono- and disaccharides increases the physical stability of neutral insulin solutions, but concurrently the chemical and biological stability decrease to an unacceptable degree. Addition of Ca-ions in low concentrations offers a physiologically acceptable method for stabilizing neutral insulin solutions against heat precipitation without affecting the quality, including the chemical and biological stability.