US4017360A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for purifying hepatitis B antigen
Assignee: Merck and Co Inc
•
Filing: 1975-05-14
•
Granted: 1977-04-12
•
Expires: 1995-05-14
Abstract
Abstract Hepatitis B antigen useful as vaccine is prepared from clarified plasma of hepatitis B donors by treating with pepsin at a pH wherein pepsin is enzymatically active, treating with urea, and optionally treating with formaldehyde.
Inventors
- 👤 Alexander U. Bertland
- 👤 Alfred A. Tytell
- 👤 George P. Lampson
- 👤 Eugene Buynak
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 16:04
CPC Classifications
C; C07; C07K; C07K14/00; C07K14/005; A; A61; A61K; A61K39/00; C12; C12N; C12N2730/00; C12N2730/00011; C12N2730/10011; C12N2730/10111; C12N2730/10122
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
77 words
A method for purifying hepatitis B antigen from a partially purified concentrate obtained from clarified plasma containing hepatitis B antigen comprising treating the concentrate with a quantity of pepsin effective to digest proteinaceous matter at a pH within the range wherein pepsin is enzymatically active, treating the concentrate with a quantity of urea effective to dissociate proteinaceous matter, and removing pepsin, pepsin degradation products and urea, and optionally adding formaldehyde in a concentration effective to inactivate viruses.
Claim 2
Independent Claim
77 words
A method for purifying hepatitis B antigen from a partially purified concentrate obtained from clarified plasma containing hepatitis B antigen comprising treating the concentrate with a quantity of pepsin effective to digest proteinaceous matter at a pH within the range wherein pepsin is enzymatically active, treating the concentrate with a quantity of urea effective to dissociate proteinaceous matter, and removing pepsin, pepsin degradation products and urea, and optionally adding formaldehyde in a concentration effective to inactivate viruses.
Claim 3
Dependent Claim
19 words
A method according to claim 1 wherein the pH of the concentrate is adjusted to about 2 with HCl.
Claim 4
Dependent Claim
28 words
A method according to claim 1 wherein the pepsin is added until its concentration is about 1 microgram/ml. per from about 40 to about 500 micrograms of protein.
Claim 5
Dependent Claim
20 words
A method according to claim 1 wherein urea is added until its concentration is from about 4M to about 8M.
Claim 6
Dependent Claim
19 words
A method according to claim 1 wherein formaldehyde is added following removal of pepsin, pepsin degradation products and urea.
Claim 7
Dependent Claim
22 words
A method according to claim 5 wherein the formaldehyde is added until its concentration is from about 50 to about 200 micrograms/ml.
Claim 8
Dependent Claim
14 words
A method according to claim 5 wherein removal is effected by filtration and chromatography.
References Cited (Backward Citations)
US3636191A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-04-11 | 1980-10-11 | 1981-04-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-11 | 1984-10-11 | 1985-04-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-11 | 1988-10-11 | 1989-04-12 | $7700.00 | Window Closed / Lapsed |