Patent US4771004A successfully refreshed from Google Patents.
US4771004A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for in vitro determination of transdermal absorption
Assignee: Teikoku Seiyaku Co Ltd
•
Filing: 1986-08-29
•
Granted: 1988-09-13
•
Expires: 2006-08-29
Abstract
Abstract Provided is a novel barrier membrane and a method using the barrier membrane for testing the transdermal penetration behavior of a bioactive agent. The method employs shed snake skin as the model barrier membrane. In particular, the method comprises the steps of providing a dose of a donor formulation containing the bioactive agent, and a receptor solution, with a barrier membrane of shed snake skin separating the donor formulation and receptor solution. The receptor solution is then serially sampled and assayed in order to determine the concentration of the bioactive agent in the receptor solution. The use of the shed snake skin has been found to provide reproducible and uniform results as a model barrier membrane. As well, the shed snake skin offers the advantages of being readily available and storable for an extended period of time.
Inventors
- 👤 Takeru Higuchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:08
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/5005; G01N33/5008; G01N33/5082; G01N33/5088; G01N13/00; G01N33/15; Y; Y10; Y10S; Y10S424/00; Y10S424/07
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
42 words
In a system for testing the human skin penetration behavior of a bioactive agent comprising a model barrier membrane positioned between a donor formulation and a receptor solution, the improvement which comprises said model barrier membrane consisting essentially of shed snake skin.
Claim 2
Dependent Claim
42 words
In a system for testing the human skin penetration behavior of a bioactive agent comprising a model barrier membrane positioned between a donor formulation and a receptor solution, the improvement which comprises said model barrier membrane consisting essentially of shed snake skin.
Claim 3
Dependent Claim
17 words
The system of claim 1, wherein the shed snake skin is that of the black rat snake.
Claim 4
Dependent Claim
127 words
In an in vitro testing method for testing the ability of formulations to deliver bioactive agents across human skin, comprising the steps of (i) providing a dose of a donor formulation containing the bioactive agent to be followed, and a receptor solution, (ii) providing a barrier membrane to separate the donor formulation and the receptor solution, (iii) contacting the donor formulation with one side of the barrier membrane and the receptor solution with the other side of the barrier membrane for a time sufficient to produce penetration of the barrier membrane by the donor formulation, and, (iv) sampling the receptor solution and assaying same to determine the concentration of the bioactive agent in the receptor solution, the improvement wherein the model barrier membrane comprises shed snake skin.
Claim 5
Dependent Claim
127 words
In an in vitro testing method for testing the ability of formulations to deliver bioactive agents across human skin, comprising the steps of (i) providing a dose of a donor formulation containing the bioactive agent to be followed, and a receptor solution, (ii) providing a barrier membrane to separate the donor formulation and the receptor solution, (iii) contacting the donor formulation with one side of the barrier membrane and the receptor solution with the other side of the barrier membrane for a time sufficient to produce penetration of the barrier membrane by the donor formulation, and, (iv) sampling the receptor solution and assaying same to determine the concentration of the bioactive agent in the receptor solution, the improvement wherein the model barrier membrane comprises shed snake skin.
Claim 6
Dependent Claim
24 words
The in vitro testing method of claim 3, wherein the shed snake skin of the barrier membrane is that of the black rat snake.
Claim 7
Dependent Claim
14 words
The in vitro testing method of claim 3, wherein the bioactive agent is indomethacin.
Claim 8
Dependent Claim
24 words
The in vitro testing method of claim 3, wherein the system in which the model barrier membrane is employed is a Franz Diffusion Cell.
Claim 9
Dependent Claim
23 words
The in vitro testing method of claim 3, wherein the formulation comprises enhancers for the delivery of the bioactive agent across human skin.
Claim 10
Dependent Claim
28 words
The in vitro testing method of claim 3, wherein the shed snake skin comprising the barrier membrane has been stored for at least one week prior to use.
Claim 11
Dependent Claim
28 words
The in vitro testing method of claim 3, wherein the shed snake skin comprising the barrier membrane had been stored for at least one month prior to use.
Claim 12
Independent Claim
115 words
A method for testing the penetration behavior of a bioactive agent across human skin, comprising the steps of (i) providing a dose of a donor formulation containing the bioactive agent to be followed, and a receptor solution, (ii) providing a barrier membrane of shed snake skin to separate the donor formulation and the receptor solution, (iii) contacting the donor formulation with one side of the barrier membrane and the receptor solution with the other side of the barrier membrane for a time sufficient to produce penetration of the barrier membrane by the donor formulation, and (iv) sampling the receptor solution and assaying same to determine the concentration of the bioactive agent in the receptor solution.
Claim 13
Independent Claim
115 words
A method for testing the penetration behavior of a bioactive agent across human skin, comprising the steps of (i) providing a dose of a donor formulation containing the bioactive agent to be followed, and a receptor solution, (ii) providing a barrier membrane of shed snake skin to separate the donor formulation and the receptor solution, (iii) contacting the donor formulation with one side of the barrier membrane and the receptor solution with the other side of the barrier membrane for a time sufficient to produce penetration of the barrier membrane by the donor formulation, and (iv) sampling the receptor solution and assaying same to determine the concentration of the bioactive agent in the receptor solution.
Claim 14
Dependent Claim
21 words
The method of claim 10, wherein the shed snake skin of the barrier membrane is that of the black rat snake.
Claim 15
Dependent Claim
23 words
The method of claim 10, wherein the donor dose formulation comprises enhancers for the delivery of the bioactive agent across the human skin.
Claim 16
Dependent Claim
21 words
The method of claim 10, wherein the receptor solution is periodically sampled and assayed for the concentration of the bioactive agent.
Claim 17
Dependent Claim
11 words
The method of claim 10, wherein the bioactive agent is indomethacin.
Claim 18
Dependent Claim
24 words
The method of claim 10, wherein the shed snake skin of the barrier membrane had been stored at least one week prior to use.
Claim 19
Dependent Claim
24 words
The method of claim 10, wherein the shed snake skin of the barrier membrane had been stored at least one month prior to use.
References Cited (Backward Citations)
US3590634A
Cited
US4594884A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-09-13 | 1992-03-14 | 1992-09-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-09-13 | 1996-03-14 | 1996-09-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-09-13 | 2000-03-14 | 2000-09-13 | $7700.00 | Window Closed / Lapsed |