BUFFERED POLYOL-HORMONE MIXTURE FOR USE IN CHRONIC PARENTERAL HORMONE ADMINISTRATION

A method of preventing the precipitation of proteins, such as hormone preparations, within drug delivery systems that depend on the fluidity of the infusate for proper function while extending and maintaining the biological activity of the protein during its period of storage in the drug delivery system. A polyol, such as glycerol, is mixed with the protein solution prior to the introduction of the solution into the drug delivery system. The polyol is added in amount between about 10 and 90% by volume sufficient to prevent precipitation of the protein during long-term storage in the drug delivery device. A physiologically compatible buffer system in concentration between about 1 mMolar and 1000 mMolar sufficient to maintain the pH of the solution within about one unit of the optimum pH of the protein is added to maintain the bioactivity of the protein during its extended period of storage. According to one form of usage, the protein-polyol-buffer solution is injected to the pressurized drug storage reservoir of an implanted infusion pump by injection through the patient's skin. As the solution is discharged from the delivery device by the constant pressure exerted upon the storage chamber, its low rate of flow is controlled by a restricted fluid passage. The solution is conveyed to an infusion site and diluted by the blood stream.