Stable crystalline (6S)- and (6R)-tetrahydrofolic acid
US6271374A · kind A · utility
11Cited by
3References
17Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jan 26, 1998 |
| Grant date | Aug 7, 2001 |
| Priority date | — |
| Expiry date | Jan 26, 2018 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61P43/00
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
Pure and extremely stable crystalline (6S)- and (6R)-tetrahydrofolic acids, absolutely inert even when exposed to air and elevated temperature without stabilizers being added, are prepared by a crystallization process at a pH of .gtoreq.3.5 for the preparation of crystalline (6S)-tetrahydrofolic acid and at a pH of .gtoreq.2 for the preparation of crystalline (6R)-tetrahydrofolic acid.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.