SELF-POWERED VAPOR PRESSURE DELIVERY DEVICE

• US 3,840,009 A
• Filed: 12/27/1971
• Issued: 10/08/1974
• Est. Priority Date: 12/27/1971
• Status: Expired due to Term

• Current Assignee: Alan S. Michaels, Richard G. Buckles, Su IL Yum
• Original Assignee: Alan S. Michaels, Richard G. Buckles, Su IL Yum
• Inventors: Michaels, Alan S., Buckles, Richard G., Yum, Su Il
• Primary Examiner(s): Gaudet, Richard A.
• Assistant Examiner(s): Recla, Henry J.
• Application Number:
  US05/212,140
• Time in Patent Office: 1,016 Days
• Field of Search: 128/260,272,261 222/491,189
• US Class Current: 604/892.1
• CPC Class Codes: A61K 9/0004 Osmotic delivery systems; Sustained release driven by osmosis, thermal energy or gas
• 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
• CPC Class Codes: A61M 37/00 Other apparatus for introducing media into the body for reproduction or fertilisation A61B17/425; apparatus for iontophoresis or cataphoresis A61N1/30; Percutany, i.e. introducing medicines into the body by diffusion through the skin salt baths A61H33/04

Abstract

A self-powered vapor pressure delivery device for the controlled and continuous dispensing of an active agent employing in a preferred embodiment outer and inner chambers in functional relationships. The inner chamber is a sealed bag comprised of a flexible and substantially vapor and fluid impermeable material. The bag is freely positioned within an outer casing. The bag is filled with a volatile propellant and is expandably responsive to the vapor pressure of the propellant at the temperature of use, such as to cause the bag to distend so as to reduce the volume of the outer chamber. The active agent in the outer chamber is thereby caused to flow through a flow resistive means which is provided in the outer chamber.

Claims

1. A self-powered dispenser for administering an active agent internally to a mammal consisting essentially of:

a. a hollow casing whose inner surface defines an active agent impermeable chamber and whose outer surface defines the exterior of the dispenser;

b. an outlet in said casing communicating from said chamber to said exterior of the dispenser;

c. a bladder positioned within said chamber the inner surface of said bladder defining a sealed inner chamber, the active agent being contained in said chamber externally of said bladder and in contact with the outer surface of said bladder, said bladder being formed of a flexible material and being expandable in response to a pressure increase within the inner chamber from an initial state in which the volume defined by the outer surface of the bladder is less than the volume of said chamber to an expanded state in which the outer surface of the bladder conforms approximately to the shape of said chamber and the volume defined thereby is approximately the volume of said chamber;

d. a self-actuated active agent flow resisting means within said outlet for metering the discharge of agent from said chamber at a substantially constant rate; and

e. a liquified gas propellant having a vapor pressure greater than one atmosphere at the physiological temperature of the mammal contained within said inner chamber;

whereby when said dispenser is placed internally of the mammal said propellant vaporizes in response to said physiological temperature causing said bladder to expand continuously from said initial state to said expanded state and thereby concurrently and continuously displace active agent from said chamber via said outlet and said means in vivo at a controlled rate.

2. The dispenser of claim 1 wherein the outer surface of the bladder in said expanded state is substantially contiguous with the inner surface of the casing.

3. The dispenser of claim 1 including:

f. an inlet in said casing communicating from said exterior to said chamber for charging active agent to said chamber.

4. The dispenser of claim 1 wherein the casing is constructed of a flexible material.

5. The dispenser of claim 1 wherein the same has a specific gravity of at least 1.5 and is of a size, weight and shape which enables it to be retained in the rumen of polygastric mammals.

6. The dispenser of claim 1 wherein the bladder is comprised of a polymeric film material.

7. The dispenser of claim 6 wherein the polymeric film is a laminate.

8. The dispenser of claim 6 wherein the bladder is in the form of a pleated accordian bellows.

9. The dispenser of claim 6 wherein the bladder is comprised of a metal foil.

10. The dispenser of claim 1 wherein the bladder is comprised of polyethylene, polyvinylidene, polyvinylidene chloride, aluminum foil, polypropylene, nylon, polytrifluorochloroethylene, polytetrafluoroethylene, polyvinylacetate, polyvinylchloride, or combinations thereof.

11. The dispenser of claim 1 including:

f. a conduit connected to said outlet and leading to the administration site of the agent.

12. The dispenser of claim 1 wherein the active agent substantially fills that portion of the volume of said chamber not occupied by said bladder in its initial state.