US4123520A
Expired / Lapsed
US
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Method for preparing high molecular weight meningococcal Group C vaccine
Assignee: Merck and Co Inc
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Filing: 1977-08-01
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Granted: 1978-10-31
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Expires: 1997-08-01
Abstract
Abstract A vaccine against Group C meningococcal meningitis consisting of a polysaccharide of which at least 80% by weight has a molecular weight in excess of 1,000,000 daltons is prepared. The polysaccharide was isolated from Group C hexadecyl trimethylammonium bromide cell paste with 1.0M CaCl 2 extraction and purified by phenol extraction, ultracentrifugation at 100,000 g. and ethanol fractionation (30%-45% v/v in ethanol).
Inventors
- 👤 Arpi Hagopian
- 👤 Dennis J. Carlo
- 👤 Thomas H. Stoudt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 22:12
CPC Classifications
A; A61; A61K; A61K39/00; A61K39/02; A61K39/095
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
124 words
A process for the preparation of antigenic meningococcal polysaccharide active against Group C meningococci wherein at least 80% of the polysaccharide has a molecular weight in excess of 100,000,000 daltons comprising: a. growing a culture of Group C meningococci in a suitable culture media; b. isolating the polysaccharide from culture by precipitation with a quaternary ammonium halide salt; c. dissolving the precipitate in aqueous calcium chloride solution; d. precipitating the polysaccharide by bringing the aqueous polysaccharide solution to 75%-85% v/v in ethanol; e. dissolving the precipitate in buffer at a pH of 6.8 to 7.2, and extracting with aqueous phenol solution; f. precipitating the polysaccharide by bringing the phenol extracted solution to a concentration of 40%-50% v/v in ethanol; and g. collecting the precipitate.
Claim 2
Dependent Claim
124 words
A process for the preparation of antigenic meningococcal polysaccharide active against Group C meningococci wherein at least 80% of the polysaccharide has a molecular weight in excess of 100,000,000 daltons comprising: a. growing a culture of Group C meningococci in a suitable culture media; b. isolating the polysaccharide from culture by precipitation with a quaternary ammonium halide salt; c. dissolving the precipitate in aqueous calcium chloride solution; d. precipitating the polysaccharide by bringing the aqueous polysaccharide solution to 75%-85% v/v in ethanol; e. dissolving the precipitate in buffer at a pH of 6.8 to 7.2, and extracting with aqueous phenol solution; f. precipitating the polysaccharide by bringing the phenol extracted solution to a concentration of 40%-50% v/v in ethanol; and g. collecting the precipitate.
Claim 3
Independent Claim
76 words
A method of purifying a polysaccharide of Group C meningococci comprising dissolving a precipitate of the polysaccharide in an aqueous buffer at pH 6.8 to 7.2; extracting the solution comprising the polysaccharide a plurality of times with an aqueous phenol solution; bringing the polysaccharide solution to a concentration of 30%-33% v/v in ethanol and ultracentrifuged; then bringing the supernatant fluid to a concentration of 40%-50% v/v in ethanol to precipitate the polysaccharide, and collecting the polysaccharide.
Claim 4
Independent Claim
76 words
A method of purifying a polysaccharide of Group C meningococci comprising dissolving a precipitate of the polysaccharide in an aqueous buffer at pH 6.8 to 7.2; extracting the solution comprising the polysaccharide a plurality of times with an aqueous phenol solution; bringing the polysaccharide solution to a concentration of 30%-33% v/v in ethanol and ultracentrifuged; then bringing the supernatant fluid to a concentration of 40%-50% v/v in ethanol to precipitate the polysaccharide, and collecting the polysaccharide.
Claim 5
Dependent Claim
17 words
A method according to claim 2 where the buffer is aqueous 0.4 to 0.6 molar sodium acetate.
Claim 6
Dependent Claim
17 words
A method according to claim 2 where the aqueous phenol solution is 70%-80% v/v in aqueous buffer.
Claim 7
Dependent Claim
17 words
A method according to claim 4 where the aqueous buffer is 0.4 to 0.6 molar sodium acetate.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-10-30 | 1982-05-01 | 1982-10-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-10-30 | 1986-05-01 | 1986-10-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-10-30 | 1990-05-01 | 1990-10-31 | $7700.00 | Window Closed / Lapsed |