Compensating drug delivery system

• US 6,582,393 B2
• Filed: 05/29/2001
• Issued: 06/24/2003
• Est. Priority Date: 05/29/2001
• Status: Expired due to Fees

• Current Assignee: TheraFuse, Inc.
• Original Assignee: TheraFuse, Inc.
• Inventors: Sage, Burton H. Jr.
• Primary Examiner(s): Hayes, Michael J.
• Assistant Examiner(s): Lam, Ann Y.
• Application Number:
  US09/867,003
• Publication Number:
  US 20030018304A1
• Time in Patent Office: 756 Days
• Field of Search: 604/48, 604/65-67, 604/181, 604/93.01, 604/118, 604/121, 604/131, 604/30, 604/31, 604/113, 604/114, 604/246, 604/250
• US Class Current: 604/65
• CPC Class Codes: A61M 2037/0023 Drug applicators using microneedles
• CPC Class Codes: A61M 2037/0061 Methods for using microneedles
• CPC Class Codes: A61M 2205/3653 by Joule effect, i.e. electric resistance
• CPC Class Codes: A61M 37/0015 by using microneedles
• CPC Class Codes: A61M 5/148 flexible, e.g. independent bagsA61M5/155 takes precedence
• CPC Class Codes: A61M 5/152 pressurised by contraction of elastic reservoirs containers for dispensing contents by contraction of an elastic bag provided therein, in general B65D83/0061
• CPC Class Codes: A61M 5/16804 Flow controllers
• CPC Class Codes: A61M 5/16881 Regulating valves on-off valves, e.g. clamps A61M39/28

Abstract

A compensating drug delivery system for delivery of medicaments to animals is described. A drug-containing reservoir is connected to a needle array through a flow tube. Medicament delivery to the animal through this flow tube is regulated by the combined action of a metering means and a valving means, and inaccuracies in delivery rate are compensated. The metering means and the valving means are microprocessor controlled to insure that the medication administered is according to a pre-established protocol.

Claims

1. A device for delivery of a liquid medicament to a subject comprising:

a reservoir for containing the liquid medicament under pressure;

a needle for penetrating the skin of the subject;

a flow tube in fluid communication with the needle and the reservoir;

a memory device for storing a schedule of delivery of the liquid medicament to a subject in terms of dose or dosing rate or both dose and dosing rate as a function of time;

a meter for measuring properties of flow in the tube; and

a valve for starting and stopping liquid flow in the flow tube in a periodic manner;

wherein

the time the valve is open or closed each period is adjusted to compensate for changes in system parameters as determined by measurements made by the meter so that the schedule of delivery is followed.

2. The device of claim 1 comprising two matable components;

a first disposable component comprising the medicament containing reservoir, the needle, and the flow tube, and a second reusable component comprising the valve, the meter and the memory device.

3. The device of claim 1 or 2 wherein the liquid medicament is an insulin formulation.

4. The device of claim 1 or 2 wherein the liquid medicament is a narcotic analgesic formulation.

5. The device of claim 1 wherein the needle is at least one microneedle.

6. The device of claim 5 wherein the at least one microneedle has an outside diameter of less than 0.2 mm.

7. The device of claim 1 wherein the meter measures the time interval required for an increment of the liquid medicament to flow a prescribed distance along the flow tube.

8. The device of claim 1 wherein the device compensates for a change in pressure in the reservoir or a change in the viscosity of the liquid medicament, or both, by making a linear adjustment of the time that the valve is open or closed.

9. The device of claim 1 wherein the device compensates for a change of flow tube lumen dimensions by making a quadratic adjustment of the time that the valve is open or closed.

10. The device of claim 2 wherein the device compensates for a change in flow tube lumen dimensions by making a quadratic adjustment of the time that the valve is open or closed when the reusable component is first mated to a fresh disposable component.

11. The device of claim 2 wherein the disposable component includes a surface with an adhesive for adhering the disposable component to the skin of a subject.

12. The device of claim 1 wherein the meter measures the volumetric flow rate of the liquid medicament flowing in the flow tube.

13. The device of claim 1 wherein the meter measures the velocity of the liquid medicament flowing in the flow tube.

14. The device of claim 12 wherein the meter measures the volumetric flow rate by detecting a voltage generated by the flow the ions in the liquid medicament through a magnetic field.

20. The device of claim 1, wherein the needle is at least one microneedle, wherein the device compensates for a change of flow tube lumen dimensions by making a quadratic adjustment of the time that the valve is open or closed, and wherein the meter measures the velocity of the liquid medicament flowing in the flow tube.

21. The device of claim 20, wherein the device includes an adhesive for adhering the device to the skin of a subject.

22. The device of claim 20, wherein the liquid medicament is an insulin formulation.

23. The device of claim 20, wherein the device comprises two matable components;

a first disposable component comprising the medicament containing reservoir, the needle, and the flow tube, and a second reusable component comprising the valve, the meter and the memory device.

15. A method of delivering a liquid medicament to a subject including the steps of

a) providing a two component drug delivery device wherein the first component comprises a reservoir for containing a liquid medicament under pressure, a needle for penetrating the skin of the subject, and a flow tube connecting the reservoir and the needle, and wherein the second component is matable with the first component and comprises a valve for starting and stopping flow in the tube, a memory device for storing a delivery schedule for the liquid medicament in terms of dose or dosing rate or both dose and dosing rate as a function of time, and a meter for measuring properties of the flow of the liquid medicament along the flow tube,

b) using the meter to make measurements of a property of flow of the liquid medicament, and

c) using the measurements of a property of flow to deliver the liquid medicament according to the schedule by adjusting the time that the valve is open or closed to compensate for changes in system parameters.

16. The method of claim 15 wherein the system parameters being compensated for comprise at least one of reservoir pressure, medicament viscosity, and flow tube lumen dimensions.

17. The method of claim 15 wherein the system parameters being compensated for comprise reservoir pressure, medicament viscosity, and flow tube lumen dimensions.

18. The method of claim 16 wherein the adjustment of the time that the valve is open or closed to compensate for a change of flow tube lumen dimensions is a quadratic adjustment.

19. The method of claim 16 wherein the adjustment of the time that the valve is open or closed to compensate for changes in reservoir pressure and viscosity is a linear adjustment.