Patent US4289764A successfully refreshed from Google Patents.
US4289764A
Expired / Lapsed
US
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Steroid compositions
Assignee: Drythanol Ltd
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Filing: 1979-12-04
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Granted: 1981-09-15
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Expires: 1999-12-04
Abstract
Abstract The invention provides a pharmaceutical composition for topical application comprising an essentially saturated solution of hydrocortisone in aqueous propylene glycol solution containing at least 15% but less than 50% by weight of propylene glycol, the proportion of hydrocortisone in the total composition being at least 0.08% but not greater than 0.4% by weight of aqueous propylene glycol and from 0.025 to 0.4% based on the total weight of the composition, the said composition being characterized by a pH in the range of 2.7 to 3.3, and the substantial absence of metallic cations. Such compositions have excellent storage stability and surprisingly high effectiveness of the hydrocortisone contained therein.
Inventors
- 👤 Hyman Yarrow
- 👤 Martin Whitefield
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 14:52
CPC Classifications
A; A61; A61K; A61K47/00; A61K47/06; A61K47/08; A61K47/10; A61K47/12; A61K9/00; A61K9/0012; A61K9/0014
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
109 words
In a pharmaceutical composition for topical application comprising an essentially saturated solution of hydrocortisone in an aqueous propylene glycol solution containing at least 15% but less than 50% by weight of propylene glycol, the proportion of hydrocortisone in the total composition being at least 0.08% but not greater than 0.4% by weight of aqueous propylene glycol and from 0.025 to 0.4% based on the total weight of the composition, the improvement which consists in including in the composition sufficient of a pharmacologically acceptable compatible non-toxic acid to bring the pH of the composition to within the range 2.7 to 3.3, and in substantially excluding metallic cations from the composition.
Claim 2
Dependent Claim
109 words
In a pharmaceutical composition for topical application comprising an essentially saturated solution of hydrocortisone in an aqueous propylene glycol solution containing at least 15% but less than 50% by weight of propylene glycol, the proportion of hydrocortisone in the total composition being at least 0.08% but not greater than 0.4% by weight of aqueous propylene glycol and from 0.025 to 0.4% based on the total weight of the composition, the improvement which consists in including in the composition sufficient of a pharmacologically acceptable compatible non-toxic acid to bring the pH of the composition to within the range 2.7 to 3.3, and in substantially excluding metallic cations from the composition.
Claim 3
Dependent Claim
21 words
The improvement of claim 1 in which the said acid is an aqueous carboxylic acid which is also a chelating agent.
Claim 4
Dependent Claim
13 words
The improvement of claim 1 in which the said acid is citric acid.
Claim 5
Dependent Claim
37 words
A pharmaceutical composition for topical application consisting essentially of hydrocortisone 0.05 to 0.3%, propylene glycol about 20%, emulsifying ointment BP about 40%, water about 40%, and sufficient citric acid to adjust the pH to 2.7 to 3.3.
Claim 6
Dependent Claim
37 words
A pharmaceutical composition for topical application consisting essentially of hydrocortisone 0.05 to 0.3%, propylene glycol about 20%, emulsifying ointment BP about 40%, water about 40%, and sufficient citric acid to adjust the pH to 2.7 to 3.3.
References Cited (Backward Citations)
US3899580A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-09-14 | 1985-03-16 | 1985-09-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-09-14 | 1989-03-16 | 1989-09-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-09-14 | 1993-03-16 | 1993-09-15 | $7700.00 | Window Closed / Lapsed |