US4436738A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stabilized estradiol cream composition
Assignee: Warner Chilcott Co LLC
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Filing: 1982-03-15
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Granted: 1984-03-13
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Expires: 2002-03-15
Abstract
Abstract Loss of potency of estradiol cream compositions found to be due to unexpected oxidation of estradiol. Improved cream composition comprises 1% or less 17β-estradiol in the presence of stabilizing members selected from phenolic-type antioxidants, metal chelating agents, and suspending agents.
Inventors
- 👤 Robert J. Bequette
- 👤 Linda G. Hobbs
- 👤 Joseph A. Scott
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 23:17
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/0012; A61K9/0014; A61K31/00; A61K31/56; A61K31/565
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
119 words
A cream composition for topical estrogen therapy which comprises 17β-estradiol of a concentration of about 1% or less on a weight basis relative to the whole composition and the remainder being a pharmaceutically acceptable carrier wherein said carrier contains as stabilizers from about 0.01 to about 10% by weight of at least one member selected from (a) one or more phenolic-type antioxidants selected from the group consisting of t-butylhydroquinone, di-t-amylhydroquinone, di-t-butylhydroquinone, butylhydroxytoluene, butylhydroxyanisole, pyrocatechol, pyrogallol, propyl gallate, and nordihydroguaiaretic acid; (b) one or more metal chelating agents selected from the group consisting of the sodium edetates (EDTA), and edatic acid; and (c) one or more suspending agents selected from the group consisting of carbomer, carboxymethylcellulose, hydroxypropyl methylcellulose and methylcellulose.
Claim 2
Dependent Claim
119 words
A cream composition for topical estrogen therapy which comprises 17β-estradiol of a concentration of about 1% or less on a weight basis relative to the whole composition and the remainder being a pharmaceutically acceptable carrier wherein said carrier contains as stabilizers from about 0.01 to about 10% by weight of at least one member selected from (a) one or more phenolic-type antioxidants selected from the group consisting of t-butylhydroquinone, di-t-amylhydroquinone, di-t-butylhydroquinone, butylhydroxytoluene, butylhydroxyanisole, pyrocatechol, pyrogallol, propyl gallate, and nordihydroguaiaretic acid; (b) one or more metal chelating agents selected from the group consisting of the sodium edetates (EDTA), and edatic acid; and (c) one or more suspending agents selected from the group consisting of carbomer, carboxymethylcellulose, hydroxypropyl methylcellulose and methylcellulose.
Claim 3
Dependent Claim
71 words
The composition of claim 1 wherein the concentration of antioxidant is less than 0.1% by weight; the metal chelating agent is a sodium edetate which is present in a concentration of less than 0.1% by weight; at least one of the suspending agents is present in a concentration of 1% or less; and 17β-estradiol is present at a 0.1% or less concentration on a weight basis relative to the whole composition.
Claim 4
Dependent Claim
67 words
The composition of claim 1 wherein the antioxidant is tertiary butylhydroquinone at a concentration of 0.2 parts per 1,000 parts cream; the metal chelating agent is disodium edetate at a concentration of 0.5 part per 1,000 parts cream; the suspending agent is hydroxypropyl methylcellulose at a concentration of 3 parts per 1,000 parts cream and 17β-estradiol is at the concentration of 0.1 part per 1,000 parts cream.
Claim 5
Dependent Claim
44 words
The composition as recited in claim 3 which further comprises per 1,000 parts cream: stearyl alcohol, 70 parts; glyceryl monostearate, 40 parts; white ceresin wax, 70 parts; sodium lauryl sulfate, 3 parts; methylparaben, 1.5 parts; propylene glycol, 100 parts; and purified water, 712 parts.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-03-13 | 1987-09-12 | 1988-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-03-13 | 1991-09-12 | 1992-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-03-13 | 1995-09-12 | 1996-03-13 | $7700.00 | Window Closed / Lapsed |