Hypromellose acetate succinate and method for producing the same
US10888525B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 30, 2017 |
| Grant date | Jan 12, 2021 |
| Priority date | — |
| Expiry date | Mar 3, 2038 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08B13/00
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
There are provided HPMCAS (hypromellose acetate succinate) having such a property that a solution of the HPMCAS in a solvent has a controlled viscosity; and a method for producing the HPMCAS. More specifically, provided are HPMCAS having such property that a solution of 10 parts by weight of the HPMCAS in 100 parts by weight of a mixed solvent having a weight ratio of methylene chloride to methanol of 1:1 has a viscosity at 20° C. of 135 mPa·s or less; and a method for producing the HPMCAS including an esterification step of adding acetic anhydride and succinic anhydride to a solution of hypromellose in glacial acetic acid in the presence of sodium acetate to obtain a reaction product mixture, wherein the succinic anhydride is added intermittently, and a precipitation step of mixing the reaction product mixture with water to precipitate the HPMCAS.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.