Time watch or depletion indicator for removable substances
First Claim
1. A device for indicating the depletion of a removable substance by observing a color change, said device comprising:
- (a) a permeable film; and
(b) a porous matrix containing a mixture consisting essentially of (1) a predetermined amount of a removable substance (I) containing acidic or basic groups and (II) capable of diffusing through said permeable film (a) and (2) a pH color indicator that undergoes a color change at a predetermined pH range without a chemical reaction with (I) without a broader pH range, said broader pH range bounded by a first pH measurable at said predetermined amount corresponding to when said removable substance commences to diffuse through said permeable film (a) and a second pH measurable after said removable substance has diffused through said permeable film and said color has occurred, said permeable film (a) containing said porous matrix (b).
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Accused Products
Abstract
A novel depletion indicator (time watch) for removable substances containing acid or basic groups is disclosed, together with a novel method of use therefor. The removable substance of a predetermined concentration comes into contact with a suitable pH color indicator that can change color at a predetermined pH range within a much larger measurable pH range, which color change occurs as the concentration of the removable substance diminishes by passing through a permeable film containing both the removable substance and the pH color indicator.The color change occurs at a predetermined time, e.g., the same time that the active ingredient has diminished to the point it is determined to be inactive.
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Citations
30 Claims
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1. A device for indicating the depletion of a removable substance by observing a color change, said device comprising:
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(a) a permeable film; and (b) a porous matrix containing a mixture consisting essentially of (1) a predetermined amount of a removable substance (I) containing acidic or basic groups and (II) capable of diffusing through said permeable film (a) and (2) a pH color indicator that undergoes a color change at a predetermined pH range without a chemical reaction with (I) without a broader pH range, said broader pH range bounded by a first pH measurable at said predetermined amount corresponding to when said removable substance commences to diffuse through said permeable film (a) and a second pH measurable after said removable substance has diffused through said permeable film and said color has occurred, said permeable film (a) containing said porous matrix (b). - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A time watch for determining when a predetermined period of time has elapsed by observing a color change, comprising:
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(a) a permeable film; (b) a porous matrix containing a mixture consisting essentially of (1) a controlled release substance having acidic or basic groups diffusable through said permeable film (a); and
(2) a suitable pH color indicator that undergoes a color change without a chemical reaction with said controlled release substance (1) and in a predetermined pH range within a broader pH range bounded by;(aa) a pH of (a) (1) measurable before any migration of (b)(1) from the porous matrix and before any color change has occurred; and (bb) a pH of (a)(2) measurable after migration of (b)(1) from the porous matrix and after the color change has occurred; (c) an impermeable crushable pouch containing an acid or base having acidic or a basic groups with the proviso that if the controlled release substance of (b)(1) is an acid, the crushable pouch contains a base and if the controlled release substance is a base, the pouch contains an acid; and
with a second proviso that said pouch and porous matrix are separated by said permeable film through which (b)(1) is diffusable; and(d) a transparent impermeable container containing (a), (b) and (c) by which the porous matrix can be observed. - View Dependent Claims (30)
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21. A device for indicating the depletion of a controlled release substance by observing a color change comprising:
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(A) a mixture consisting essentially of; (1) a controlled release substance containing acid or basic groups; (2) a suitable pH color indicator that undergoes a color change without a chemical reaction with said controlled release substance and at a pH within a pH range bounded by a first pH measured as the concentration of said controlled release substance starts to diminish in said device and a second pH measured after said controlled release substance has completely diminished; and (B) a permeable film containing said mixture, said film characterized by having the ability to pass said controlled release substance therethrough.
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22. A time watch for determining when a predetermined period of time has elapsed by observing a color change, said time watch comprising:
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(a) a permeable film; (b) an impermeable crushable pouch containing a controlled release substance having acidic or basic groups and diffusable through said permeable film (a); (c) a porous matrix containing a mixture consisting essentially of (1) an acid or a base and (2) a suitable pH color indicator that undergoes a color change without a chemical reaction with said controlled release substance and at a predetermined pH range within a broader pH range, said broader pH range bounded by (aa) a pH measurable before said controlled release substance initially contacts (c)(1) with the proviso that if the groups of said controlled release substance are acidic, then (c)(1) is a base and if the groups of said controlled release are basic, then (c)(1) is an acid and (bb) a second pH measurable after said controlled release substance has intimately contacted and has completely neutralized (c)(1) and said pH color indicator has completely changed color;
said permeable film (a) separating said impermeable crushable pouch (b) and said porous matrix (c); and(d) a transparent impermeable container containing (a), (b), and (c) permitting said porous matrix (c) to be observed. - View Dependent Claims (23)
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24. A time watch for determining when a predetermined period of time has elapsed by observing a color change, said time watch comprising:
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(a) a permeable film; (b) a porous matrix containing a mixture consisting essentially of (1) a predetermined amount of a removable substance containing acidic or basic groups and capable of diffusing through said permeable film and (2) a suitable pH color indicator that undergoes a color change without a chemical reaction with said removable substances, and at a predetermined pH range within a broader pH range, said broader pH range being bounded by a first pH measurable at said predetermined amount when said removable substance commences to diffuse through said permeable film and a second pH measurable after said removable substance has diffused through said permeable film and the color change has occurred; (c) an impermeable crushable pouch covering said permeable film and said porous matrix, with the proviso that said impermeable crushable pouch and said porous matrix are separated by said permeable film; and (d) a transparent impermeable container containing (a), (b), and (c) permitting said porous matrix (b) to be observed.
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25. A method for indicating the depletion of a controlled release substance having a known period of effectiveness after activation of said controlled release substance, by a color change, said method comprising:
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(a) activating the release of a removable substance through a permeable film, said removable substance being placed in a porous matrix containing a mixture consisting essentially of said removable substance and a suitable pH indicator, said removable substance being present in a predetermined amount, and capable of diffusing through said permeable film, and containing acidic or basic groups, said suitable pH color indicator capable of undergoing a color change without a chemical reaction with the removable substance and at a predetermined pH range within a broader pH range, said broader pH range being bounded by a pH measurable at said predetermined amount when said removable substance commences to diffuse through said permeable film and a second pH measurable after said removable substance has diffused through said permeable film and the color change has occurred, and (b) noting said color change. - View Dependent Claims (26, 27, 28, 29)
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Specification