Hydroxypropyl methylcellulose acetate succinate and method for producing same
AssigneeShin-Etsu Chemical Co., Ltd.
InventorsKentaro MIKI, Shinnosuke INADA, Taishi KITAGUCHI, Akira KITAMURA, Mitsuo NARITA
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Abstract
Provided is an industrial and efficient method for producing hydroxypropyl methylcellulose acetate succinate that exhibits an enhanced dissolution rate into a solvent. This method includes a liquid removal step, a first drying step, and a second drying step, wherein the first drying step involves drying hydroxypropyl methylcellulose acetate succinate under reduced pressure until it reaches a water content above 0% by mass and lower than or equal to 30% by mass while maintaining the product temperature above 0° C. and lower than or equal to 25° C.
Claims8
A method for producing hydroxypropyl methylcellulose acetate succinate comprising:
- a liquid removal step of
- allowing hydroxypropyl methylcellulose, an acetylating agent, and a succinoylating agent to react with each other in the presence of a catalyst to produce a reaction solution,
- mixing water with the reaction solution to obtain a suspension of hydroxypropyl methylcellulose acetate succinate, and
- removing liquid from the suspension of hydroxypropyl methylcellulose acetate succinate to obtain liquid-removed hydroxypropyl methylcellulose acetate succinate;
- a first drying step of drying the liquid-removed hydroxypropyl methylcellulose acetate succinate under reduced pressure until it reaches a water content above 0% by mass and lower than or equal to 30% by mass while maintaining the product temperature above 0° C. and lower than or equal to 25° C. to obtain first dried hydroxypropyl methylcellulose acetate succinate;
- and
- a second drying step of further drying the first dried hydroxypropyl methylcellulose acetate succinate to obtain hydroxypropyl methylcellulose acetate succinate.
A hydroxypropyl methylcellulose acetate succinate comprising pores each having a diameter of 0.01 to 3.0 μm, wherein said pores have a pore volume of 0.5 to 2.0 mL/g as measured by mercury porosimetry.
Dependencies are inferred from the claim text.