Patent US3923939A successfully refreshed from Google Patents.
US3923939A
Expired / Lapsed
US
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Process for improving release kinetics of a monolithic drug delivery device
Assignee: Alza Corp
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Filing: 1974-06-07
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Granted: 1975-12-02
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Expires: 1994-06-07
Abstract
Abstract A process for improving the release kinetics of a monolithic active agent delivery device comprising a shaped body of a dispersion of particulate active agent, such as a drug, with a polymer matrix, such as ethylene/vinylacetate copolymer, by substantially reducing the initial burst of active agent from the device when it is placed in its environment of use. The process involves prior to placing the body in its use environment removing, such as by water washing, the particulate drug from the exterior surface of the body to form an agent depleted layer of polymer matrix voided by the removal of the agent, the thickness of the layer being at least 5% of the overall body thickness.
Inventors
- 👤 Richard W Baker
- 👤 Alan S Michaels
- 👤 Felix Theeuwes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:41
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/0012; A61K9/0034; A61K9/0039; A61K9/0002; A61K9/0004; A61K9/0048; A61K9/0051; A61P; A61P31/00; A61P5/00
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
99 words
METHOD FOR SUBSTANTIALLY REDUCING THE INITIAL BURST OF ACTIVE AGENT RELEASE FROM A MONOLITHIC ACTIVE AGENT DELIVERY DEVICE WHEN SAID DEVICE IS PLACED IN ITS ENVIRONMENT OF USE, SAID DEVICE COMPRISING A SHAPED BODY OF A DISPERSION OF PARTICULATE ACTIVE AGENT WITHIN A POLYMER MATRIX COMPRISING PRIOR TO PLACING SAID SHAPED BODY IN SAID ENVIRONMENT, REMOVING THE PARTICULATE AGENT FROM THE EXTERIOR SURFACE OF SAID BODY TO FORM AN AGENT DEPLETED LAYER OF POLYMER MATRIX VOIDED BY SUCH REMOVAL OF PARTICULATE ACTIVE AGENT, THE THICKNESS OF SAID BEING AT LEAST ABOUT 5% OF THE OVERALL THICKNESS OF THE BODY.
Claim 2
Dependent Claim
99 words
METHOD FOR SUBSTANTIALLY REDUCING THE INITIAL BURST OF ACTIVE AGENT RELEASE FROM A MONOLITHIC ACTIVE AGENT DELIVERY DEVICE WHEN SAID DEVICE IS PLACED IN ITS ENVIRONMENT OF USE, SAID DEVICE COMPRISING A SHAPED BODY OF A DISPERSION OF PARTICULATE ACTIVE AGENT WITHIN A POLYMER MATRIX COMPRISING PRIOR TO PLACING SAID SHAPED BODY IN SAID ENVIRONMENT, REMOVING THE PARTICULATE AGENT FROM THE EXTERIOR SURFACE OF SAID BODY TO FORM AN AGENT DEPLETED LAYER OF POLYMER MATRIX VOIDED BY SUCH REMOVAL OF PARTICULATE ACTIVE AGENT, THE THICKNESS OF SAID BEING AT LEAST ABOUT 5% OF THE OVERALL THICKNESS OF THE BODY.
Claim 3
Dependent Claim
25 words
The method of claim 1 wherein said removing is done by washing the body in a liquid which is inert relative to said polymer matrix.
Claim 4
Dependent Claim
10 words
The method of claim 2 wherein said liquid is water.
Claim 5
Dependent Claim
34 words
The method of claim 2 wherein said device is a diffusion type device and said washing is carried out at an elevated temperature at which diffusion of the agent from the matrix is enhanced.
Claim 6
Dependent Claim
26 words
The method of claim 2 wherein the polymer matrix is an ethylene/vinyl acetate copolymer and the washing is carried out at about 50*C to about 60*C.
Claim 7
Dependent Claim
36 words
The method of claim 2 wherein the device is an osmotic bursting type device and the washing is carried out at an elevated temperature at which imbibition of said liquid by the active agent is enhanced.
Claim 8
Dependent Claim
23 words
The method of claim 1 wherein the thickness of the layer is about 5% to 25% of the overall thickness of the body.
Claim 9
Dependent Claim
109 words
In a process for making a monolithic drug delivery device comprising a dispersion of solid particulate drug in a polymer matrix comprising the steps of forming a dispersion of the solid particulate drug within said matrix and forming the dispersion into a shaped body adapted for placement in the environment of use of the device, the improvement comprising the additional step of removing the solid particulate drug from the surface of said body to Form a drug depleted layer of polymer matrix voided by the removal of the particulate solid drug therefrom, the thickness of said layer being at least about 5% of the overall thickness of said body.
Claim 10
Dependent Claim
109 words
In a process for making a monolithic drug delivery device comprising a dispersion of solid particulate drug in a polymer matrix comprising the steps of forming a dispersion of the solid particulate drug within said matrix and forming the dispersion into a shaped body adapted for placement in the environment of use of the device, the improvement comprising the additional step of removing the solid particulate drug from the surface of said body to Form a drug depleted layer of polymer matrix voided by the removal of the particulate solid drug therefrom, the thickness of said layer being at least about 5% of the overall thickness of said body.
Claim 11
Dependent Claim
25 words
The improvement of claim 8 in which the thickness of said layer is about 5% to about 25% of the overall thickness of the body.
Claim 12
Dependent Claim
25 words
The improvement of claim 8 wherein said removing is done by washing the body in a liquid which is inert relative to the polymer matrix.
Claim 13
Dependent Claim
10 words
The improvement of claim 10 wherein the liquid is water.
Claim 14
Dependent Claim
34 words
The improvement of claim 10 wherein the device is a diffusion type device and said washing is carried out at an elevated temperature at which diffusion of the drug from the matrix is enhanced.
Claim 15
Dependent Claim
27 words
The improvement of claim 12 wherein the polymer matrix is made of an ethylene/vinyl acetate copolymer and the elevated temperature is from about 50*C to about 60*C.
Claim 16
Dependent Claim
36 words
The improvement of claim 10 wherein the device is an osmotic bursting type device and the washing is carried out at an elevated temperature at which the imbibition of liquid by the active agent is enhanced.
References Cited (Backward Citations)
US3402240A
Cited
US3700380A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-01 | 1979-06-02 | 1979-12-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-01 | 1983-06-02 | 1983-12-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-01 | 1987-06-02 | 1987-12-02 | $7700.00 | Window Closed / Lapsed |