US4806360A
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US
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Synthetic melanin aggregates
Assignee: Amcol International Corp
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Filing: 1987-10-23
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Granted: 1989-02-21
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Expires: 2007-10-23
Abstract
Abstract Melanin compositions include a melanin pigment incorporated within an internal pore network defined by a polymeric particle matrix. The melanin compositions may be produced by in situ oxidation of melanin precursors within the pore network, or by absorption of a melanin pigment dispersed in a suitable vehicle or carrier. The melanin compositions are found to display enhanced absorbance of ultraviolet radiation when compared to melanin pigments which are not incorporated in such a polymeric particle matrix.
Inventors
- 👤 Helen Leong
- 👤 Martin Katz
- 👤 Anne Delk
- 👤 David Berliner
- 👤 Sergio Nacht
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:05
CPC Classifications
A; A61; A61K; A61K8/00; A61K8/18; A61K8/72; A61K8/02; A61K8/0241; A61K8/0279; A61Q; A61Q19/00; A61Q19/04; A61K2800/00; A61K2800/40; A61K2800/56
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
64 words
A composition comprising substantially non-collapsible particles each defining a network of internal pores and having melanin pigment entrapped within said network of pores, wherein said particles are polymers having a cross-linking density of at least about 10% and said melanin pigment has been introduced to said pores by absorption of melanin pigment or by in situ conversion of a melanin precursor within said pores.
Claim 2
Dependent Claim
64 words
A composition comprising substantially non-collapsible particles each defining a network of internal pores and having melanin pigment entrapped within said network of pores, wherein said particles are polymers having a cross-linking density of at least about 10% and said melanin pigment has been introduced to said pores by absorption of melanin pigment or by in situ conversion of a melanin precursor within said pores.
Claim 3
Dependent Claim
14 words
A composition as in claim 1, wherein said polymeric particles are substantially non-collapsible beads.
Claim 4
Dependent Claim
14 words
A composition as in claim 1, wherein the polymeric beads are a styrene-divinylbenzene copolymer.
Claim 5
Dependent Claim
19 words
A composition as in claim 1, wherein said cross-linking density is in the range from about 20% to 80%.
Claim 6
Dependent Claim
23 words
A composition as in claim 2, wherein said beads have an average diameter in the range from about 5 μm to 100 μm.
Claim 7
Dependent Claim
21 words
A composition as in claim 5, wherein said average diameter is in the range from about 10 μm to 40 μm.
Claim 8
Dependent Claim
17 words
A composition as in claim 1, wherein the polymeric beads are a methyl methacrylate-ethylene glycol dimethacrylate copolymer.
Claim 9
Dependent Claim
22 words
A composition as in claim 1, wherein the melanin precursor is selected from the group consisting of L-dopa, tyrosine, tryptophan, and cysteine.
Claim 10
Dependent Claim
12 words
A composition as in claim 1, wherein the melanin precursor is L-dopa.
Claim 11
Dependent Claim
33 words
A composition as in claim 1, wherein the melanin pigment is introduced into preformed beads by absorption of a dispersion of melanin pigment in a suitable carrier, followed by evaporation of the carrier.
Claim 12
Dependent Claim
21 words
A composition as in claim 10, wherein the carrier is selected from the group consisting of water, buffer, and alkaline solution.
Claim 13
Independent Claim
51 words
A method for preparing a melanin particle composition, said method comprising: introducing a melanin precursor into a plurality of substantially non-collapsible polymeric particles having a cross-linking density of a least about 10% and each defining a network of internal pores; and oxidizing the melanin precursor to melanin pigment within said pores.
Claim 14
Independent Claim
51 words
A method for preparing a melanin particle composition, said method comprising: introducing a melanin precursor into a plurality of substantially non-collapsible polymeric particles having a cross-linking density of a least about 10% and each defining a network of internal pores; and oxidizing the melanin precursor to melanin pigment within said pores.
Claim 15
Dependent Claim
22 words
A method as in claim 12, wherein the melanin precursor is selected from the group consisting of L-dopa, tyrosine, tryptophan, and cysteine.
Claim 16
Dependent Claim
15 words
A method as in claim 12, wherein the oxidation is promoted by an oxidation catalyst.
Claim 17
Dependent Claim
13 words
A method as in claim 14, wherein the oxidation catalyst is an enzyme.
Claim 18
Dependent Claim
11 words
A method as in claim 15, wherein the enzyme is tyrosinase.
Claim 19
Independent Claim
56 words
A method for preparing a melanin particle composition, said method comprising: introducing a dispersion of melanin pigment in a suitable carrier into a plurality of substantially non-collapsible polymeric particles having a cross-linking density of at least about 10% and each defining a network of internal pores; and evaporating the carrier from the pores of the particles.
Claim 20
Independent Claim
56 words
A method for preparing a melanin particle composition, said method comprising: introducing a dispersion of melanin pigment in a suitable carrier into a plurality of substantially non-collapsible polymeric particles having a cross-linking density of at least about 10% and each defining a network of internal pores; and evaporating the carrier from the pores of the particles.
Claim 21
Dependent Claim
21 words
A method as in claim 17, wherein the carrier is selected from the group consisting of water, buffer, and alkaline solution.
Claim 22
Dependent Claim
18 words
A method as in claim 17, wherein the melanin is in the form of a finely divided powder.
Claim 23
Independent Claim
78 words
A method for protecting skin from exposure to ultraviolet radiation, said method comprising: applying to the skin a composition comprising substantially non-collapsible polymeric particles having a cross-linking density of at least about 10% and each defining a network of internal pores and having melanin pigment entrapped within said network of pores, wherein said melanin pigment has been introduced to said pores by absorption of melanin pigment or by in situ conversion of a melanin precursor within said pores.
Claim 24
Independent Claim
78 words
A method for protecting skin from exposure to ultraviolet radiation, said method comprising: applying to the skin a composition comprising substantially non-collapsible polymeric particles having a cross-linking density of at least about 10% and each defining a network of internal pores and having melanin pigment entrapped within said network of pores, wherein said melanin pigment has been introduced to said pores by absorption of melanin pigment or by in situ conversion of a melanin precursor within said pores.
Claim 25
Dependent Claim
19 words
A method as in claim 20, wherein said cross-linking density is in the range from about 20% to 80%.
Claim 26
Dependent Claim
23 words
A method as in claim 20, wherein said beads have an average diameter in the range from about 5 μm to 100 μm.
Claim 27
Dependent Claim
21 words
A method as in claim 22, wherein said average diameter is in the range from about 10 μm to 40 μm.
Claim 28
Dependent Claim
22 words
A method as in claim 20, wherein the melanin precursor is selected from the group consisting of L-dopa, tyrosine, tryptophan, and cysteine.
Claim 29
Dependent Claim
12 words
A method as in claim 20, wherein the melanin precursor is L-dopa.
Claim 30
Dependent Claim
33 words
A method as in claim 20, wherein the melanin pigment is introduced into preformed beads by absorption of a dispersion of melanin pigment in a suitable carrier, followed by evaporation of the carrier.
Claim 31
Dependent Claim
21 words
A method as in claim 26, wherein the carrier is selected from the group consisting of water, buffer, and alkaline solution.
Claim 32
Dependent Claim
14 words
A method as in claim 20, wherein the polymeric beads are a styrene-divinylbenzene copolymer.
Claim 33
Dependent Claim
17 words
A method as in claim 20, wherein the polymeric beads are a methyl methacrylate-ethylene glycol dimethacrylate copolymer.
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