Self adjustable exit port

• US 6,217,906 B1
• Filed: 09/17/1999
• Issued: 04/17/2001
• Est. Priority Date: 03/24/1997
• Status: Expired due to Term

• Current Assignee: Intarcia Therapeutics, Inc.
• Original Assignee: ALZA Corporation (Johnson & Johnson)
• Inventors: Gumucio, Juan C., Brown, James E., Dionne, Keith E.
• Primary Examiner(s): Page, Thurman K.
• Assistant Examiner(s): TRAN, SUSAN T
• Application Number:
  US09/397,507
• Time in Patent Office: 578 Days
• Field of Search: 424/473, 424/451, 604/892.1
• US Class Current: 424/473
• CPC Class Codes: A61K 9/0004 Osmotic delivery systems; Sustained release driven by osmosis, thermal energy or gas

Abstract

A delivery device having a first chamber containing an osmotic agent, a membrane forming a wall of the first chamber through which fluid is imbibed by osmosis, a second chamber containing a beneficial agent to be delivered, and a moveable piston separating the two chambers. In fluid communication with the second chamber is an orifice which comprises a slit valve. In the presence of pressure, the beneficial agent pushes through the slit, opening up a channel for delivery of the beneficial agent and creating flow. Because the slit remains closed in the absence of flow (or when the pressure is below the pressure required to open the slit), back diffusion of external fluids is eliminated when the slit is closed, which prevents contamination of the beneficial agent in the second chamber by external fluids. In addition, forward diffusion of the beneficial agent out of the capsule is prevented when the slit is closed. The slit valve opens only to the minimum dimension required to allow the flow generated by the osmotic pumping rate. The slit valve also allows a flow path to open around any obstruction in the slit valve to prevent clogging.

Claims

1. A method of forming a delivery device comprising the steps of:

filling a chamber of the delivery device with a beneficial agent having a known viscosity;

providing an exit passage through which the beneficial agent is delivered, the exit passage comprising a first portion having a wall which is at an angle to a direction of flow of the beneficial agent, the exit passage also comprising a slit orifice downstream of the first portion; and

selecting the angle of the wall with respect to the direction of flow of the beneficial agent based on the viscosity of the beneficial agent so that the force of the flow of the beneficial agent opens the slit orifice to deliver the beneficial agent substantially without diffusion of external liquids into the chamber.

2. The method of claim 1, further comprising the step of forming the first portion of the exit passage in the shape of a cone with the slit orifice intersecting an apex of the cone.

3. A method of forming a delivery device comprising:

inserting a beneficial agent into a capsule;

locating an osmotic agent in the capsule;

positioning a flexible member at least partially inside the capsule; and

forming a slit orifice in the flexible member, the slit orifice being closed when a pressure of the beneficial agent in the capsule is less than a predetermined pressure and being opened when the pressure of the beneficial agent is greater than the predetermined pressure thereby permitting flow of the beneficial agent through the slit orifice and out of the capsule.

4. The method of claim 3, wherein the beneficial agent is inserted into the capsule after the flexible member has been positioned at least partially inside the capsule.

5. The method of claim 3, wherein the slit orifice in formed in said flexible member after the flexible member has been positioned at least partially inside the capsule.

6. The method of claim 3, wherein said forming of the slit orifice includes inserting at least one of a hypodermic needle, pin, or blade through at least a portion of the flexible member.

7. The method of claim 3, wherein the flexible member is positioned partially inside the capsule.

8. The method of claim 3, wherein the flexible member is positioned completely inside the capsule.

9. The method of claim 3, further comprising inserting a flow moderator at least partially inside the flexible member.

10. The method of claim 3, further comprising locating a member having an inner recess at least partially inside said enclosure.

11. The method of claim 10, further comprising locating the flexible member at least partially inside the inner recess of the member.

12. The method of claim 3, further comprising forming a plurality of slit orifices in the flexible member.

13. A method of forming an osmotic delivery system comprising:

locating a beneficial agent in a capsule;

providing an osmotic agent for applying osmotic pressure to the beneficial agent; and

inserting a plug having a slit orifice at least partially into the capsule, the slit orifice being closed when a pressure of the beneficial agent is less than a predetermined pressure and being opened when the pressure of the beneficial agent is greater than the predetermined pressure thereby permitting flow of the beneficial agent through the slit orifice and out of the capsule.

14. The method of claim 13, further comprising forming the slit orifice in the plug.

15. The method of claim 13, further comprising inserting a piston into the capsule.