Patent US2993837A successfully refreshed from Google Patents.
US2993837A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Enteric coated tablets
Assignee: Merck Frosst Canada and Co
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Filing: 1959-07-13
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Granted: 1961-07-25
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Expires: 1979-07-13
Abstract
No abstract record available.
Inventors
- 👤 John F Millar
- 👤 Samuel W Harder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:46
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/20; A61K9/28; A61K9/2806; A61K9/2833; A61K9/284
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
123 words
A SOLID MEDICINAL ORAL DOSAGE UNIT CONTAINING AT LEAST ONE MEDICINAL AGENT, COMPRISING A SHAPED CORE CONTAINING A MEDICINAL AGENT SURROUNDED BY AN ENTERIC LAYER OF A PARTIALLY ESTERIFIED POLYVINYL ALCOHOL IN WHICH THE HYDROXYL GROUPS ARE PARTLY ESTERFIED BY PHTHALIC ACID, PARTLY ACETYLATED, AND PARTLY UNREPLACED, SAID PARTIALLY ESTERIFIED POLYVINYL ALCOHOL HAVING A DEGREE OF A POLYMERIZATION OF FROM 200 TO 800, A PHTHALYL CONTENT OF FROM 38 TO 59% AND AN ACETYL CONTENT OF FROM 0.2 TO 12% SAID ENTERIC COATING BEING SUBSTANTIALLY RESISTANT TO DISINTEGRATION IN AQUESOUS FLUIDS HAVING A PH LOWER THAN 3.5 FOR A PERIOD OF AT LEAST 2 HOURS, AND CAPABLE OF DISINTEGRATING IN AQUEOUS FLUIDS HAVING A PH OF AT LEAST 5.5 IN FROM 10-30 MINUTES.
Claim 2
Dependent Claim
123 words
A SOLID MEDICINAL ORAL DOSAGE UNIT CONTAINING AT LEAST ONE MEDICINAL AGENT, COMPRISING A SHAPED CORE CONTAINING A MEDICINAL AGENT SURROUNDED BY AN ENTERIC LAYER OF A PARTIALLY ESTERIFIED POLYVINYL ALCOHOL IN WHICH THE HYDROXYL GROUPS ARE PARTLY ESTERFIED BY PHTHALIC ACID, PARTLY ACETYLATED, AND PARTLY UNREPLACED, SAID PARTIALLY ESTERIFIED POLYVINYL ALCOHOL HAVING A DEGREE OF A POLYMERIZATION OF FROM 200 TO 800, A PHTHALYL CONTENT OF FROM 38 TO 59% AND AN ACETYL CONTENT OF FROM 0.2 TO 12% SAID ENTERIC COATING BEING SUBSTANTIALLY RESISTANT TO DISINTEGRATION IN AQUESOUS FLUIDS HAVING A PH LOWER THAN 3.5 FOR A PERIOD OF AT LEAST 2 HOURS, AND CAPABLE OF DISINTEGRATING IN AQUEOUS FLUIDS HAVING A PH OF AT LEAST 5.5 IN FROM 10-30 MINUTES.
References Cited (Backward Citations)
US2897122A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-07-24 | 1965-01-23 | 1965-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-07-24 | 1969-01-23 | 1969-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-07-24 | 1973-01-23 | 1973-07-25 | $7700.00 | Window Closed / Lapsed |