Positive pressure drug releasing device
AssigneeIowa State University Research Foundation, Inc.
InventorsKeith E. Magoon, Lawrence E. Evans, Frederick B. Hembrough
Life of this patent
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Abstract
A positive pressure long-term drug delivery device particularly useful for the intravaginal or intrauterine release of a drug capable of passing through a diffusion membrane and being absorbed by the vaginal or uterine epithelium. The device includes a tubular casing having a plunger urged by a compression spring to create a continuous positive pressure on a drug in liquid form within the chamber of the casing, a supported membrane at one end of the casing through which such drug diffuses at a predetermined rate, and resilient elements at the opposite end of the casing for facilitating retention of the device throughout the term of administration of the drug.
Claims9
A positive pressure drug releasing device comprising an elongated casing having a tubular side wall defining a chamber;
- said casing being open at one end and having an end wall at the other end thereof;
- a diffusion membrane secured to said casing and extending across said open end;
- a plunger slidably disposed within said chamber for axial movement therein;
- a drug solution in said chamber between said plunger and said membrane;
- said drug solution being diffusable through said membrane and absorbable by the body wall of a cavity in which said device is implanted;
- and a compression spring interposed between said plunger and said end wall;
- said spring being in a state of compression for producing a substantially uniform positive pressure on said drug solution of a magnitude sufficient to render negligible the effects of back diffusion osmotic pressure when the device is in use.
The device of claim 8 in which said sleeve and fingers are formed of flexible non-irritating polymeric material.
Dependencies are inferred from the claim text.