Patent US3849056A successfully refreshed from Google Patents.
US3851648A
Expired / Lapsed
US
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Zero-order release device
Assignee: Mead Johnson and Co LLC
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Filing: 1973-10-11
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Granted: 1974-12-03
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Expires: 1993-10-11
Abstract
Abstract A diffusible solid is released by diffusion into a fluid medium from a cavity within a container through an opening therein at a rate which is independent of the amount of solid present in the container. Zero-order release is effected by the shape of the cavity and the opening. The rate is related to the solubility and to the diffusion constant of the solid in the fluid medium. For a given substance, the rate of release is determined by cavity shape and dimensions of the diffusion opening. The device is adapted for use in both liquid and gaseous media and can be used for the zero-order release of drug substances into the system of a living organism, and for non-medical uses.
Inventors
- 👤 D Brooke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 20:20
CPC Classifications
A; A61; A61J; A61J3/00; A61J3/08; A01; A01M; A01M7/00; A01M7/0089; A01M7/0092; A61F; A61F6/00; A61F6/06; A61F6/14; A61K; A61K9/00; A61K9/0002; A61K9/0004; A61K9/20; A61K9/2072; A61M; A61M31/00; A61M31/002; A61M37/00
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
230 words
A device for the automatic release at a substantially constant predetermined rate of a diffusible solid into a fluid medium into which said solid has a propensity to diffuse when said device is immersed in said medium which comprises, a container which is insoluble in said medium, impermeable thereto, and impermeable to said solid, said container having a slot in the surface thereof defining an elongated opening of uniform length and width having two ends and two sides with the narrower dimension at the ends and the longer dimension at the sides, said slot communicating in its entirety with an internal cavity within said container said cavity being defined by an accuate wall and a pair of parallel congruent planar end walls arranged at right angles to said slot and adjacent the ends thereof, and a pair of inwardly extending congruent planar side walls adjacent the opposite sides of said slot and in substantially divergent radial relation to said slot, and extending to said rear wall. a means for diffusing said solid from within said cavity into the immersing medium including a diffusible solid housed within said cavity as a homogenous mass in bonded relation to the inner wall surface of the cavity and having a surface thereof facing and opposing said slot opening to expose the diffusable solid surface to said fluid medium when said device is immersed therein.
Claim 2
Independent Claim
230 words
A device for the automatic release at a substantially constant predetermined rate of a diffusible solid into a fluid medium into which said solid has a propensity to diffuse when said device is immersed in said medium which comprises, a container which is insoluble in said medium, impermeable thereto, and impermeable to said solid, said container having a slot in the surface thereof defining an elongated opening of uniform length and width having two ends and two sides with the narrower dimension at the ends and the longer dimension at the sides, said slot communicating in its entirety with an internal cavity within said container said cavity being defined by an accuate wall and a pair of parallel congruent planar end walls arranged at right angles to said slot and adjacent the ends thereof, and a pair of inwardly extending congruent planar side walls adjacent the opposite sides of said slot and in substantially divergent radial relation to said slot, and extending to said rear wall. a means for diffusing said solid from within said cavity into the immersing medium including a diffusible solid housed within said cavity as a homogenous mass in bonded relation to the inner wall surface of the cavity and having a surface thereof facing and opposing said slot opening to expose the diffusable solid surface to said fluid medium when said device is immersed therein.
Claim 3
Dependent Claim
18 words
The device defined in claim 1 wherein the entire volume of the cavity is occupied by said solid.
Claim 4
Dependent Claim
59 words
The device defined in claim 1 wherein less than the entire volume of said cavity is occupied by said solid such that the rear wall of said cavity is entirely covered thereby and the surface thereof opposite said slot is of arcuate concave configuration defining a segment of a cylinder wall the axis of which lies within said slot.
Claim 5
Dependent Claim
30 words
The device of claim 1 wherein the side walls of said cavity are positioned with respect to one another at an angle in the range of from 30* to 270*.
Claim 6
Dependent Claim
32 words
The device of claim 1 wherein the rear wall of said cavity is of arcuate concave configuration defining a segment of a cylinder wall the axis of which lies within said slot.
Claim 7
Dependent Claim
27 words
The device of claim 1 adapted for use in a gaseous medium and said solid possesses a vapor pressure such that sublimation thereof occurs under ambient conditions.
Claim 8
Dependent Claim
12 words
The device of claim 1 wherein said fluid medium is a liquid.
Claim 9
Dependent Claim
29 words
The device of claim 1 wherein said solid is biologically active and release thereof into said medium is for the purpose of exerting a biological effect in the medium.
Claim 10
Dependent Claim
19 words
The device of claim 8 wherein said solid is a drug substance and said medium is a biological liquid.
Claim 11
Dependent Claim
43 words
The device of claim 8 wherein said solid is a suspension or a dispersion of a particulate pure drug substance in an inert carrier solid wherein said carrier solid is substantially insoluble in said medium but permeable to diffusion of said drug substance.
Claim 12
Dependent Claim
31 words
The device of claim 1 wherein said device is sized and shaped for placement and retention within the uterine cavity of a mammal and said solid is a biologically active substance.
Claim 13
Dependent Claim
11 words
The device of claim 11 wherein said solid possesses hormonal activity.
Claim 14
Dependent Claim
21 words
The device of claim 11 wherein said Container is a cylinder approximately 3.2 cm. in length and 0.24 cm. in diameter.
Claim 15
Dependent Claim
67 words
The device of claim 13 wherein said slot is arranged in an axial direction on the side of said cylinder, the width of said slot is from about 0.02 to about 0.06 cm., the angle formed by said side walls of said cavity is from about 30* to about 140*, and said solid has a solubility in said medium from about 1.7 mcg./ml. to about 570 mcg./ml.
Claim 16
Dependent Claim
40 words
The device of claim 1 wherein said container is a ring adapted for placement and retention within the vagina of a mammal, said solid is a biologically active substance, and said slot and cavity are positioned concentrically on said ring.
Claim 17
Dependent Claim
15 words
The device of claim 15 wherein said slot traverses the entire circumference of said ring.
Claim 18
Dependent Claim
12 words
The device of claim 15 having multiple concentrically positioned slots and cavities.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-02 | 1978-06-03 | 1978-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-02 | 1982-06-03 | 1982-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-02 | 1986-06-03 | 1986-12-03 | $7700.00 | Window Closed / Lapsed |