US4873091A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Controlled release formulating employing resilient microbeads
Assignee: Amcol International Corp
•
Filing: 1988-05-23
•
Granted: 1989-10-10
•
Expires: 2008-05-23
Abstract
Abstract Microscopic particles containing a continuous network of pores open to the particle surface are manufactured of a spongy material. The particles are useful as controlled-release delivery systems for active substances intended for a wide range of uses including topical applications. The spongy character of the particles enhances their usefulness in applications where high pressure or high temperature are encountered, and where exceptional smoothness of feel is required.
Inventors
- 👤 Laura J. Jankower
- 👤 Larry W. Shipley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 20:40
CPC Classifications
A; A61; A61K; A61K31/00; A61K31/01; C; C08; C08J; C08J3/00; C08J3/12; A61K9/00; A61K9/14; C08J9/00; C08J9/28; C08J2201/00; C08J2201/04; C08J2201/05; C08J2201/0502; C08J2323/00; C08J2323/02; C08J2323/16
Claims Analysis
Total Claims: 98
Claim 1
Independent Claim
103 words
A method for forming solid resilient particles containing a substantially continuous network of pores open to the exterior of said particles, said method comprising: (a) combining an ethylene-propylene-diene elastomeric prepolymer with a substantially water-immiscible liquid species which is inert with respect to said prepolymer to form a homogeneous, substantially water-immiscible liquid solution; (b) dispersing said liquid solution in an aqueous solution to form a suspension; (c) polymerizing said prepolymer in said suspension to form solid resilient particles containing said water-immiscible liquid species; (d) recovering said solid resilient particles from said suspension; and (e) extracting said water-immiscible liquid species from said solid resilient particles.
Claim 2
Independent Claim
103 words
A method for forming solid resilient particles containing a substantially continuous network of pores open to the exterior of said particles, said method comprising: (a) combining an ethylene-propylene-diene elastomeric prepolymer with a substantially water-immiscible liquid species which is inert with respect to said prepolymer to form a homogeneous, substantially water-immiscible liquid solution; (b) dispersing said liquid solution in an aqueous solution to form a suspension; (c) polymerizing said prepolymer in said suspension to form solid resilient particles containing said water-immiscible liquid species; (d) recovering said solid resilient particles from said suspension; and (e) extracting said water-immiscible liquid species from said solid resilient particles.
Claim 3
Dependent Claim
27 words
A method in accordance with claim 1 in which the diene in said ethylene-propylene-diene prepolymer is a member selected from the group consisting of dicyclopentadiene and 5-ethylidene-2-norbornene.
Claim 4
Dependent Claim
17 words
A method in accordance with claim 1 in which the diene in said ethylene-propylene-diene prepolymer is dicyclopentadiene.
Claim 5
Dependent Claim
23 words
A method in accordance with claim 1 in which said ethylene-propylene-diene prepolymer has a molecular weight ranging from about 1000 to about 30,000.
Claim 6
Dependent Claim
24 words
A method in accordance with claim 1 in which said ethylene-propylene-diene prepolymer has a molecular weight ranging from about 5000 to about 10, 000.
Claim 7
Dependent Claim
23 words
A method in accordance with claim 1 in which said ethylene-propylene-diene prepolymer has an iodine number of from about 5 to about 50.
Claim 8
Dependent Claim
23 words
A method in accordance with claim 1 in which said ethylene-propylene-diene prepolymer has an iodine number of from about 8 to about 30.
Claim 9
Dependent Claim
23 words
A method in accordance with claim 1 in which step (c) comprises heating said prepolymer in the presence of a peroxide free-radical initiator.
Claim 10
Dependent Claim
27 words
A method in accordance with claim 8 in which said peroxide free-radical initiator is a member selected from the group consisting of t-butyl perbenzoate and t-butyl hydroperoxide.
Claim 11
Dependent Claim
23 words
A method in accordance with claim 1 in which step (c) comprises heating said prepolymer in the presence of a peroxyester free-radical initiator.
Claim 12
Dependent Claim
16 words
A method in accordance with claim 10 in which said peroxyester free-radical initiator is t-butyl perbenzoate.
Claim 13
Dependent Claim
38 words
A method in accordance with claim 1 in which step (c) comprises heating said prepolymer in the presence of a peroxide free-radical initiator and a polyfunctional active olefin in an amount effective in improving the cross-linking efficiency thereof.
Claim 14
Dependent Claim
27 words
A method in accordance with claim 12 in which said polyfunctional active olefin is a member selected from the group consisting of trimethylolpropane trimethacrylate and dimethylolpropane trimethacrylate.
Claim 15
Dependent Claim
16 words
A method in accordance with claim 12 in which said polyfunctional active olefin is trimethylolpropane trimethacrylate.
Claim 16
Dependent Claim
20 words
A method in accordance with claim 1 in which step (a) further comprises combining said prepolymer with a metal soap.
Claim 17
Dependent Claim
28 words
A method in accordance with claim 15 in which said metal soap is a member selected from the group consisting of cobalt naphthenate. manganese octoate and bismuth octoate.
Claim 18
Dependent Claim
15 words
A method in accordance with claim 15 in which said metal soap is cobalt naphthenate.
Claim 19
Dependent Claim
26 words
A method in accordance with claim 1 in which said water-immiscible liquid species is a member selected from the group consisting of alkanes. cycloalkanes and aromatics.
Claim 20
Dependent Claim
25 words
A method in accordance with claim 1 in which said solid resilient particles have an average diameter from about 1 micron to about 200 microns.
Claim 21
Dependent Claim
26 words
A method in accordance with claim 1 in which said solid resilient particles have a total pore volume of about 0.01 cc/g to about 4.0 cc/g.
Claim 22
Dependent Claim
26 words
A method in accordance with claim 1 in which said solid resilient particles have a total pore volume of about 0.1 cc/g to about 2.0 cc/g.
Claim 23
Dependent Claim
29 words
A method in accordance with claim 1 in which said solid resilient particles have a surface area of about 1 m 2 /g to about 500 m 2 /g.
Claim 24
Dependent Claim
29 words
A method in accordance with claim 1 in which said solid resilient particles have a surface area of about 20 m 2 /g to about 200 m 2 /g.
Claim 25
Dependent Claim
26 words
A method in accordance with claim 1 in which said solid resilient particles have an average pore diameter of about 0.001 micron to about 3.0 microns.
Claim 26
Dependent Claim
26 words
A method in accordance with claim 1 in which said solid resilient particles have an average pore diameter of about 0.003 micron to about 1.0 micron.
Claim 27
Independent Claim
73 words
A method for preparing a controlledrelease formulation of an active substance. said method comprising: (a) combining an ethylene-propylene elastomeric prepolymer with an impregnant comprising said active substance to form a homogeneous. substantially water-immiscible liquid solution; (b) dispersing said liquid solution in an aqueous solution to form a suspension; (c) polymerizing said prepolymer in said suspension to form solid resilient particles containing said impregnant; and (d) recovering said solid resilient particles from said suspension.
Claim 28
Independent Claim
73 words
A method for preparing a controlledrelease formulation of an active substance. said method comprising: (a) combining an ethylene-propylene elastomeric prepolymer with an impregnant comprising said active substance to form a homogeneous. substantially water-immiscible liquid solution; (b) dispersing said liquid solution in an aqueous solution to form a suspension; (c) polymerizing said prepolymer in said suspension to form solid resilient particles containing said impregnant; and (d) recovering said solid resilient particles from said suspension.
Claim 29
Dependent Claim
27 words
A method in accordance with claim 26 in which the diene in said ethylene-propylene-diene prepolymer is a member selected from the group consisting of dicyclopentadiene and 5-ethylidene-2-norbornene.
Claim 30
Dependent Claim
17 words
A method in accordance with claim 26 in which the diene in said ethylene-propylene-diene prepolymer is dicyclopentadiene.
Claim 31
Dependent Claim
23 words
A method in accordance with claim 26 in which said ethylene-propylene-diene prepolymer has a molecular weight ranging from about 1000 to about 30.000.
Claim 32
Dependent Claim
23 words
A method in accordance with claim 26 in which said ethylene-propylene-diene prepolymer has a molecular weight ranging from about 5000 to about 10.000.
Claim 33
Dependent Claim
23 words
A method in accordance with claim 26 in which said ethylene-propylene-diene prepolymer has an iodine number of from about 5 to about 50.
Claim 34
Dependent Claim
23 words
A method in accordance with claim 26 in which said ethylene-propylene-diene prepolymer has an iodine number of from about 8 to about 30.
Claim 35
Dependent Claim
23 words
A method in accordance with claim 26 in which step (c) comprises heating said prepolymer in the presence of a peroxide free-radical initiator.
Claim 36
Dependent Claim
27 words
A method in accordance with claim 33 in which said peroxide free-radical initiator is a member selected from the group consisting of t-butyl perbenzoate and t-butyl hydroperoxide.
Claim 37
Dependent Claim
23 words
A method in accordance with claim 26 in which step (c) comprises heating said prepolymer in the presence of a peroxyester free-radical initiator.
Claim 38
Dependent Claim
16 words
A method in accordance with claim 35 in which said peroxyester free-radical initiator is t-butyl perbenzoate.
Claim 39
Dependent Claim
38 words
A method in accordance with claim 1 in which step (c) comprises heating said prepolymer in the presence of a peroxide free-radical initiator and a polyfunctional active olefin in an amount effective in improving the cross-linking efficiency thereof.
Claim 40
Dependent Claim
27 words
A method in accordance with claim 37 in which said polyfunctional active olefin is a member selected from the group consisting of trimethylolpropane trimethacrylate and dimethylolpropane trimethacrylate.
Claim 41
Dependent Claim
16 words
A method in accordance with claim 37 in which said polyfunctional active olefin is trimethylolpropane trimethacrylate.
Claim 42
Dependent Claim
20 words
A method in accordance with claim 1 in which step (a) further comprises combining said prepolymer with a metal soap.
Claim 43
Dependent Claim
28 words
A method in accordance with claim 40 in which said metal soap is a member selected from the group consisting of cobalt naphthenate, manganese octoate and bismuth octoate.
Claim 44
Dependent Claim
15 words
A method in accordance with claim 40 in which said metal soap is cobalt naphthenate.
Claim 45
Independent Claim
45 words
A method for preparing a controlledrelease formulation of an active substance, said method comprising: (a) forming solid resilient particles containing a substantially continuous network of pores open to the exterior of said particles; and (b) impregnating said pores with an impregnant comprising said active substance.
Claim 46
Independent Claim
45 words
A method for preparing a controlledrelease formulation of an active substance, said method comprising: (a) forming solid resilient particles containing a substantially continuous network of pores open to the exterior of said particles; and (b) impregnating said pores with an impregnant comprising said active substance.
Claim 47
Dependent Claim
25 words
A method in accordance with claim 43 in which said solid resilient particles have an average diameter from about 1 micron to about 200 microns.
Claim 48
Dependent Claim
26 words
A method in accordance with claim 43 in which said solid resilient particles have a total pore volume of about 0.01 cc/g to about 4.0 cc/g.
Claim 49
Dependent Claim
26 words
A method in accordance with claim 43 in which said solid resilient particles have a total pore volume of about 0.1 cc/g to about 2.0 cc/g.
Claim 50
Dependent Claim
29 words
A method in accordance with claim 43 in which said solid resilient particles have a surface area of about 1 m 2 /g to about 500 m 2 /g.
Claim 51
Dependent Claim
29 words
A method in accordance with claim 43 in which said solid resilient particles have a surface area of about 20 m 2 /g to about 200 m 2 /g.
Claim 52
Dependent Claim
26 words
A method in accordance with claim 43 in which said solid resilient particles have an average pore diameter of about 0.001 micron to about 3.0 microns.
Claim 53
Dependent Claim
26 words
A method in accordance with claim 43 in which said solid resilient particles have an average pore diameter of about 0.003 micron to about 1.0 micron.
Claim 54
Dependent Claim
90 words
A method in accordance with claim 43 in which step (a) comprises: (i) combining an ethylene-propylene-diene prepolymer with a substantially water-immiscible liquid species which is inert with respect to said prepolymer to form a homogeneous. substantially water-immiscible liquid solution; (ii) dispersing said liquid solution in an aqueous solution to form a suspension; (iii) polymerizing said prepolymer in said suspension to form solid resilient particles containing said water-immiscible liquid species; (iv) recovering said solid resilient particles from said suspension: and (v) extracting said water-immiscible liquid species from said solid resilient particles.
Claim 55
Dependent Claim
28 words
A method in accordance with claim 51 in 10 which the diene in said ethylene-propylene-diene prepolymer is a member selected from the group consisting of dicyclopentadiene and 5-ethylidene-2-norbornene.
Claim 56
Dependent Claim
17 words
A method in accordance with claim 51 in which the diene in said ethylene-propylene-diene prepolymer is dicyclopentadiene.
Claim 57
Dependent Claim
23 words
A method in accordance with claim 51 in which said ethylene-propylene-diene prepolymer has a molecular weight ranging from about 1000 to about 30.000.
Claim 58
Dependent Claim
23 words
A method in accordance with claim 51 in which said ethylene-propylene-diene prepolymer has a molecular weight ranging from about 5000 to about 10,000.
Claim 59
Dependent Claim
23 words
A method in accordance with claim 51 in which said ethylene-propylene-diene prepolymer has an iodine number of from about 5 to about 50.
Claim 60
Dependent Claim
23 words
A method in accordance with claim 51 in which said ethylene-propylene-diene prepolymer has an iodine number of from about 8 to about 30.
Claim 61
Dependent Claim
23 words
A method in accordance with claim 51 in which step (iii) comprises heating said prepolymer in the presence of a peroxide free-radical initiator.
Claim 62
Independent Claim
27 words
A method in accordance with claim 5B in which said peroxide free-radical initiator is a member selected from the group consisting of t-butyl perbenzoate and t-butyl hydroperoxide.
Claim 63
Dependent Claim
23 words
A method in accordance with claim 51 in which step (iii) comprises heating said prepolymer in the presence of a peroxyester free-radical initiator.
Claim 64
Dependent Claim
16 words
A method in accordance with claim 60 in which said peroxyester free-radical initiator is t-butyl perbenzoate.
Claim 65
Dependent Claim
38 words
A method in accordance with claim 51 in which step (iii) comprises heating said prepolymer in the presence of a peroxide free-radical initiator and a polyfunctional active olefin in an amount effective in improving the cross-linking efficiency thereof.
Claim 66
Dependent Claim
27 words
A method in accordance with claim 62 in which said polyfunctional active olefin is a member selected from the group consisting of trimethylolpropane trimethacrylate and dimethylolpropane trimethacrylate.
Claim 67
Dependent Claim
16 words
A method in accordance with claim 63 in which said polyfunctional active olefin is trimethylolpropane trimethacrylate.
Claim 68
Dependent Claim
20 words
A method in accordance With claim 51 in which step (a) further comprises combining said prepolymer with a metal soap.
Claim 69
Dependent Claim
28 words
A method in accordance with claim 65 in which said metal soap is a member selected from the group consisting of cobalt naphthenate, manganese octoate and bismuth octoate.
Claim 70
Dependent Claim
15 words
A method in accordance with claim 65 in which said metal soap is cobalt naphthenate.
Claim 71
Dependent Claim
26 words
A method in accordance with claim 51 in which said water-immiscible liquid species is a member selected from the group consisting of alkanes. cycloalkanes and aromatics.
Claim 72
Dependent Claim
46 words
A controlled release formulation of an active substance comprising solid resilient particles formed from the reaction product of cross-linking an ethylene-propylene-diene propolymer, said said particles containing a substantially continuous network of pores open to the exterior of said particles, said pores impregnated with said active substance.
Claim 73
Dependent Claim
46 words
A controlled release formulation of an active substance comprising solid resilient particles formed from the reaction product of cross-linking an ethylene-propylene-diene propolymer, said said particles containing a substantially continuous network of pores open to the exterior of said particles, said pores impregnated with said active substance.
Claim 74
Dependent Claim
25 words
A formulation in accordance with claim 69 in which said solid resilient particles have an average diameter from about 1 micron to about 200 microns.
Claim 75
Dependent Claim
26 words
A formulation in accordance with claim 69 in which said solid resilient particles have a total pore volume of about 0.01 cc/g to about 4.0 cc/g.
Claim 76
Dependent Claim
26 words
A formulation in accordance with claim 69 in which said solid resilient particles have a total pore volume of about 0.1 cc/g to about 2.0 cc/g.
Claim 77
Dependent Claim
29 words
A formulation in accordance with claim 69 in which said solid resilient particles have a surface area of about 1 m 2 /g to about 500 m 2 /g.
Claim 78
Dependent Claim
29 words
A formulation in accordance with claim 69 in which said solid resilient particles have a surface area of about 20 m 2 /g to about 200 m 2 /g.
Claim 79
Dependent Claim
26 words
A formulation in accordance with claim 69 in which said solid resilient particles have an average pore diameter of about 0.001 micron to about 3.0 microns.
Claim 80
Dependent Claim
26 words
A formulation in accordance with claim 69 in which said solid resilient particles have an average pore diameter of about 0.003 micron to about 1.0 micron.
Claim 81
Dependent Claim
94 words
A formulation in accordance with claim 69 in which said solid resilient particles are formed by (i) combining an ethylene-propylene-diene prepolymer with a substantially water-immiscible liquid species which is inert with respect to said prepolymer to form a homogeneous, substantially water-immiscible liquid solution; (ii) dispersing said liquid solution in an aqueous solution to form a suspension; (iii) polymerizing said prepolymer in said suspension to form solid resilient particles containing said water-immiscible liquid species; (i) recovering said solid resilient particles from said suspension; and (v) extracting said water-immiscible liquid species from said solid resilient particles.
Claim 82
Dependent Claim
27 words
A formulation in accordance with claim 77 in which the diene in said ethylene-propylene-diene prepolymer is a member selected from the group consisting of dicyclopentadiene and 5-ethylidene-2-norbornene.
Claim 83
Dependent Claim
26 words
A formulation in accordance with claim 77 ib which said water-immiscible liquid species is a member selected from the group consisting of alkanes, cycloalkanes and aromatics.
Claim 84
Dependent Claim
17 words
A formulation in accordance with claim 77 in which the diene in said ethylene-propylene-diene prepolymer is dicyclopentadiene.
Claim 85
Dependent Claim
23 words
A formulation in accordance with claim 77 in which said ethylene-propylene-diene prepolymer has a molecular weight ranging from about 1000 to about 30,000.
Claim 86
Dependent Claim
23 words
A formulation in accordance with claim 77 in which said ethylenepropylene-diene prepolymer has a molecular weight ranging from about 5000 to about 10,000.
Claim 87
Dependent Claim
23 words
A formulation in accordance with claim 77 in which said ethylene-propylene-diene prepolymer has an iodine number of from about 5 to about 50.
Claim 88
Dependent Claim
23 words
A formulation in accordance with claim 77 in which said ethylene-propylene-diene prepolymer has an iodine number of from about 8 to about 30.
Claim 89
Dependent Claim
23 words
A formulation in accordance with claim 77 in which step (iii) comprises heating said prepolymer in the presence of a peroxide free-radical initiator.
Claim 90
Dependent Claim
27 words
A formulation in accordance with claim 85 in which said peroxide free-radical initiator is a member selected from the group consisting of t-butyl perbenzoate and t-butyl hydroperoxide.
Claim 91
Dependent Claim
23 words
A formulation in accordance with claim 77 in which step (iii) comprises heating said prepolymer in the presence of a peroxyester free-radical initiator.
Claim 92
Dependent Claim
16 words
A formulation in accordance with claim 87 in which said peroxyester free-radical initiator is t-butyl perbenzoate.
Claim 93
Dependent Claim
38 words
A formulation in accordance with claim 77 in which step (iii) comprises heating said prepolymer in the presence of a peroxide free-radical initiator and a polyfunctional active olefin in an amount effective in improving the cross-linking efficiency thereof.
Claim 94
Dependent Claim
27 words
A formulation in accordance with claim 89 in which said polyfunctional active olefin is a member selected from the group consisting of trimethylolpropane trimethacrylate and dimethylolpropane trimethacrylate.
Claim 95
Dependent Claim
16 words
A formulation in accordance with claim 89 in which said polyfunctional active olefin is trimethylolpropane trimethacrylate.
Claim 96
Dependent Claim
20 words
A formulation in accordance with claim 77 in which step (a) further comprises combining said prepolymer with a metal soap.
Claim 97
Dependent Claim
28 words
A formulation in accordance with claim 92 in which said metal soap is a member selected from the group consisting of cobalt naphthenate. manganese octoate and bismuth octoate.
Claim 98
Dependent Claim
15 words
A formulation in accordance with claim 92 in which said metal soap is cobalt naphthenate.
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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) | 1992-10-09 | 1993-04-10 | 1993-10-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-10-09 | 1997-04-10 | 1997-10-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-10-09 | 2001-04-10 | 2001-10-10 | $7700.00 | Window Closed / Lapsed |