Abstract: A method of preventing the precipitation of hormone preparations within drug delivery systems that depend on the fluidity of the infusate for proper function. A non-toxic water soluble detergent is dissolved in the hormone solution prior to the introduction of the solution into the drug delivery system. The detergent is added in amount sufficient to prevent precipitation of the hormone during long-term storage in the drug delivery device. According to one form of usage, the hormone-detergent solution is charged to the pressurized drug storage chamber 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.

Abstract: An implantable flow regulator for the infusion of drugs into an animal body from a pressure actuated drug delivery device, such as an implantable infusion pump. The flow regulator comprises a body having a shallow cavity divided into two chambers by a flexible diaphragm. The first of these chambers is a pressure sensing chamber. The other is a valving chamber through which the drug flows, the outlet from that chamber being centrally disposed underlying the diaphragm whereby flexing of the diaphragm in one direction as a result of increased pressure in the other chamber contacts an elastomeric sealing ring around the outlet and closes off the flow path. At least one capillary restrictor is disposed in the flow line between the drug delivery device and flow regulator. The pressure drop across this restrictor governs operation of the flow regulator valve.