Insulin delivery device

• US 4,364,385 A
• Filed: 03/13/1981
• Issued: 12/21/1982
• Est. Priority Date: 03/13/1981
• Status: Expired due to Fees

• Current Assignee: Steven V. Lossef
• Original Assignee: Steven V. Lossef
• Inventors: Lossef, Steven V.
• Primary Examiner(s): Apley, Richard J.
• Assistant Examiner(s): Wallen, T. J.
• Application Number:
  US06/243,494
• Time in Patent Office: 648 Days
• Field of Search: 424/19, 424/20, 128/213, 128/260, 128/1 R, 128/635
• US Class Current: 424/424
• CPC Class Codes: A61K 9/0024 Solid, semi-solid or solidifying implants, which are implanted or injected in body tissue compositions for intravenous administration, normal injectable solutions or dispersions for, e.g. subcutaneous administration A61K9/0019; brain implants A61K9/0085; (coated) prostheses, catheters or stents A61L
• CPC Class Codes: A61M 31/002 Devices for releasing a drug at a continuous and controlled rate for a prolonged period of time artificial gland structures or devices A61F2/022; intra-uterine contraceptive devices A61F6/14; tampons for introducing into the vagina A61F13/20, A61L15/00; suppositories or bougies for intra-vaginal or intra-uterine application A61K9/02; physical forms of medicinal preparations for sustained or differential drug release A61K9/20, A61K9/50

Abstract

An insulin delivery device comprised of a compartment limited by a semipermeable, ionically charged membrane, containing the enzymes glucose oxidase and catalase, is disclosed. The enclosed enzymes provide a means for varying the permeabiity of the membrane to stored insulin deposited within the compartment according to the magnitude of glucose concentration outside the compartment, thus facilitating continuous, physiologically regulated delivery of insulin to tissues. This device may be applicable for intracorporeal or extracorporeal use.

Claims

1. An insulin delivery device comprising:

a compartment containing insulin therein, said compartment limited by a semipermeable membrane having a plurality of pores permeable to glucose and exhibiting a net negative surface charge, said compartment adapted to contact circulating body fluids including glucose; and

enzymes contained in said compartment capable of liberating hydrogen ions from glucose diffused through said pores, from said body fluids, the molecular size of said enzymes being greater than the size of the pores of said compartment and the molecular size of the insulin being slightly smaller than the size of the pores of said compartment;

whereby, as the concentration of positive hydrogen ions increases with an increase of glucose concentration, the net negative charge of the semipermeable membrane is reduced providing an increase in the rate of diffusion of the insulin through the pores as a function of the increase of glucose concentration in the circulating body fluids.

2. An insulin delivery device in accordance with claim 1 wherein said enzymes are glucose oxidase and catalase.

3. An insulin delivery device in accordance with claims 1 and 2 whereby the pore size of said semipermeable membrane is approximately 6500 daltons.

4. An insulin delivery device in accordance with claim 2 wherein said glucose oxidase and said catalase convert the glucose into gluconic acid which dissociates into negative gluconate ions and positive hydrogen ions.

5. A method for providing a controlled release of insulin comprising the steps of:

providing a compartment limited by a semipermeable membrane having a negative surface charge and containing enzymes and insulin therein, said semipermeable membrane having pores which are smaller that the molecular size of the enzymes and are slightly larger than the molecular size of the insulin;

placing said compartment in contact with circulating body fluid containing a varying concentration of glucose, said glucose capable of diffusing through the pores of said semipermeable membrane; and

reacting the glucose with said enzymes to liberate positive hydrogen ions, the concentration of said hydrogen ions being a function of the concentration of the glucose;

whereby as the concentration of positive hydrogen ions increases with an increase of glucose concentration, the net negative charge of the semipermeable membrane is reduced providing an increase in the rate of diffusion of the insulin through the pores as a function of the glucose concentration in the circulating body fluids.

6. A method for providing a controlled release of insulin in accordance with claim 5 wherein said enzymes are glucose oxidase and catalase.