# US 9,517,191 B2 · Stable silk protein fragment compositions

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- Number: US 9,517,191 B2
- Document ID: US9517191B2
- Status: Granted
- Kind: B2
- Application number: 14/876,799
- Filed: 2015-10-06
- Published: 2016-01-28
- Granted: 2016-12-13
- Earliest claimed: 2013-09-30
- Assignees: Silk Therapeutics, Inc.
- Applicants: Silk Therapeutics, Inc.
- Inventors: Gregory H. Altman; Rebecca L. Horan; Rachel Lee Dow; Rachel M. Lind; Dylan S. Haas
- Web page: https://patentgrep.com/patent/US9517191B2

## CPC

- A61K 8/64: Proteins; Peptides; Derivatives or degradation products thereof
- A45D 33/00: Containers or accessories specially adapted for handling powdery toiletry or cosmetic substances
- A61K 8/02: characterised by special physical form
- A61K 8/0216: {Solid or semisolid forms}
- A61K 8/042: {Gels}
- A61K 8/19: containing inorganic ingredients
- A61K 8/27: Zinc; Compounds thereof
- A61K 8/29: Titanium; Compounds thereof
- A61K 8/365: Hydroxycarboxylic acids; Ketocarboxylic acids
- A61K 8/4953: {containing pyrimidine ring derivatives, e.g. minoxidil}
- A61K 8/676: {Ascorbic acid, i.e. vitamin C}
- A61K 8/735: {Mucopolysaccharides, e.g. hyaluronic acid; Derivatives thereof}
- A61K 8/922: {of vegetable origin}
- A61K 8/97: from algae, fungi, lichens or plants; from derivatives thereof
- A61K 8/9789: Magnoliopsida [dicotyledons]
- A61K 8/9794: Liliopsida [monocotyledons]
- A61K 8/987: {of species other than mammals or birds}
- A61K 9/08: Solutions {(composition of solutions A61K47/00)}
- A61K 31/375: Ascorbic acid, i.e. vitamin C; Salts thereof
- A61K 38/00: Medicinal preparations containing peptides (peptides containing beta-lactam rings A61K31/00; cyclic dipeptides not having in their molecule any other peptide link than those which form their ring, e.g. piperazine-2,5-diones, A61K31/00; ergot alkaloids of the cyclic peptide type A61K31/48; containing macromolecular compounds having statistically distributed amino acid units A61K31/74; medicinal preparations containing antigens or antibodies A61K39/00; medicinal preparations characterised by the non-active ingredients, e.g. peptides as drug carriers, A61K47/00)
- A61K 38/012: {from animals}
- A61K 45/06: Mixtures of active ingredients without chemical characterisation, e.g. antiphlogistics and cardiaca
- A61K 47/02: Inorganic compounds
- A61K 47/12: Carboxylic acids; Salts or anhydrides thereof
- A61K 47/36: Polysaccharides; Derivatives thereof, e.g. gums, starch, alginate, dextrin, hyaluronic acid, chitosan, inulin, agar or pectin
- A61P 17/00: Drugs for dermatological disorders
- A61P 17/16: Emollients or protectives, e.g. against radiation
- A61Q 17/04: Topical preparations for affording protection against sunlight or other radiation; Topical sun tanning preparations
- A61Q 19/00: Preparations for care of the skin
- A61Q 19/007: {Preparations for dry skin}
- A61Q 19/02: for chemically bleaching or whitening the skin
- A61Q 19/08: Anti-ageing preparations
- C07K 1/12: by hydrolysis {, i.e. solvolysis in general}
- C07K 14/43586: {from silkworms}
- A61K 2800/591: Mixtures of compounds not provided for by any of the codes A61K2800/592 - A61K2800/596
- A61K 2800/72: Hypo-allergenic
- A61K 2800/74: Biological properties of particular ingredients
- A61K 2800/75: Anti-irritant
- A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D)
- A45D: HAIRDRESSING OR SHAVING EQUIPMENT (wigs, toupees or the like A41G3/00, A41G5/00; hairdressers' chairs A47C1/04; hair cutting appliances, razors B26B); EQUIPMENT FOR COSMETICS OR COSMETIC TREATMENTS, e.g. FOR MANICURING OR PEDICURING
- A61P: SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
- A61Q: SPECIFIC USE OF COSMETICS OR SIMILAR TOILETRY PREPARATIONS
- C07K: PEPTIDES (peptides in foodstuffs A23; obtaining protein compositions for foodstuffs, working-up proteins for foodstuffs A23J; preparations for medicinal purposes A61K; peptides containing beta-lactam rings C07D; cyclic dipeptides not having in their molecule any other peptide link than those which form their ring, e.g. piperazine-2,5-diones, C07D; ergot alkaloids of the cyclic peptide type C07D519/02; macromolecular compounds having statistically distributed amino acid units in their molecules, i.e. when the preparation does not provide for a specific; but for a random sequence of the amino acid units, homopolyamides and block copolyamides derived from amino acids C08G69/00; macromolecular products derived from proteins C08H1/00; preparation of glue or gelatine C09H; single cell proteins, enzymes C12N; genetic engineering processes for obtaining peptides C12N15/00; compositions for measuring or testing processes involving enzymes C12Q; investigation or analysis of biological material G01N33/00)

## Abstract

A composition is disclosed that includes pure silk fibroin-based protein fragments that are substantially devoid of sericin, wherein the composition has an average weight average molecular weight ranging from about 17 kDa to about 38 kDa, wherein the composition has a polydispersity of between about 1.5 and about 3.0, wherein the composition is substantially homogeneous, wherein the composition between 0 ppm to about 500 ppm of inorganic residuals, and wherein the composition includes between 0 ppm to about 500 ppm of organic residuals.

## Claims

### Claim 1

A composition comprising:
pure silk fibroin-based protein fragments having about 0.01% (w/w) to about 10% (w/w) sericin, wherein the fragments have an average weight average molecular weight ranging from about 17 kDa to about 38 kDa,
wherein the fragments have a polydispersity of from about 1.5 to about 3.0,
wherein the composition is substantially homogeneous,
wherein the composition includes between 0 ppm to 500 ppm of inorganic residuals,
wherein the composition includes between 0 ppm to 500 ppm of organic residuals, and
wherein the composition does not spontaneously or gradually gelate and does not visibly change in color or turbidity when in a solution for at least 10 days.

### Claim 2 (depends on 1)

The composition of claim 1 wherein the inorganic residuals include lithium bromide and wherein the organic residuals include sodium carbonate.

### Claim 3 (depends on 2)

The composition of claim 2 wherein the lithium bromide residuals are measurable using a high-performance liquid chromatography lithium bromide assay, and the sodium carbonate residuals are measurable using a high-performance liquid chromatography sodium carbonate assay.

### Claim 4 (depends on 1)

The composition of claim 1 wherein the solution is an aqueous solution.

### Claim 5 (depends on 1)

The composition of claim 1 in a sealed container.

### Claim 6 (depends on 1)

The composition of claim 1 further comprising polyanhydrides.

### Claim 7 (depends on 1)

The composition of claim 1 further comprising vitamin C or a derivative thereof.

### Claim 8 (depends on 1)

The composition of claim 1 further comprising an alpha hydroxy acid selected from the group consisting of glycolic acid, lactic acid, tartaric acid and citric acid.

### Claim 9 (depends on 1)

The composition of claim 1 further comprising hyaluronic acid or its salt form at a concentration of about 0.5 wt. % to about 10.0 wt. %.

### Claim 10 (depends on 1)

The composition of claim 1 further comprising at least one of zinc oxide or titanium dioxide.

### Claim 11 (depends on 1)

The composition of claim 1 wherein the pure silk fibroin-based protein fragments are hypoallergenic.

### Claim 12 (depends on 1)

The composition of claim 1 having less than 10 colony forming units per gram.

### Claim 13 (depends on 1)

The composition of claim 1, wherein the composition does not spontaneously or gradually gelate and does not visibly change in color or turbidity when in a solution for at least 30 days.

### Claim 14 (depends on 1)

The composition of claim 1 wherein the average weight average molecular weight range and the polydispersity are measurable using a high-performance liquid chromatography assay.

### Claim 15 (depends on 1)

The composition of claim 1, wherein the fragments have an average weight average molecular weight ranging from 20 kDa to 25 kDa.

### Claim 16 (depends on 1)

The composition of claim 1, wherein the fragments have an average weight average molecular weight ranging from 25 kDa to 30 kDa.

### Claim 17 (depends on 1)

The composition of claim 1, wherein the fragments have an average weight average molecular weight ranging from 30 kDa to 35 kDa.