Provided herein are polysaccharide derivatives substituted (a) at a degree of substitution (DS1) of at least 0.05 by a fluorescent group (FG) having a mono or polycyclic ring system including at least one heteroatom selected from N, O and S and conjugated double bonds, and having an absorption band in the UV region of light and an emission band in the visible region of light, and bonded via a first linker to any one of the native functional groups of the polysaccharide repeating units; and (b) at a degree of substitution (DS2) of at least 0.05 by a charged group (CG) bonded via a second linker to any one of the native functional groups of the polysaccharide repeating units.

Provided herein are polysaccharide derivatives substituted (a) at a degree of substitution (DS1) of at least 0.05 by a fluorescent group (FG) having a mono or polycyclic ring system including at least one heteroatom selected from N, O and S and conjugated double bonds, and having an absorption band in the UV region of light and an emission band in the visible region of light, and bonded via a first linker to any one of the native functional groups of the polysaccharide repeating units; and (b) at a degree of substitution (DS2) of at least 0.05 by a charged group (CG) bonded via a second linker to any one of the native functional groups of the polysaccharide repeating units.

There is provided a method for producing hydroxypropyl methyl cellulose acetate succinate (HPMCAS), including an esterification step of reacting hydroxypropyl methyl cellulose with an acetylating agent and a succinoylating agent in the presence of an aliphatic carboxylic acid in a kneader reactor equipped with two or more stirring blades rotating around their own axes and orbitally revolving, to obtain a reaction product solution containing HPMCAS; a precipitation step of precipitating the HPMCAS by mixing the reaction product solution with water to obtain a suspension of the precipitated HPMCAS; and a washing and recovery step of washing the HPMCAS in the suspension and recovering the washed HPMCAS. Further, there is provided HPMCAS having yellowness at 20° C. of 15.0 or less, as determined in a 2% by mass solution of the HPMCAS in a mixed solvent of dichloromethane, methanol and water in a mass ratio of 44:44:10.

There is provided a method for producing hydroxypropyl methyl cellulose phthalate (HPMCP), including an esterification step of reacting hydroxypropyl methyl cellulose with a carboxybenzoylating agent in the presence of an aliphatic carboxylic acid in a kneader reactor equipped with two or more stirring blades rotating around their own axes and orbitally revolving, to obtain a reaction product solution containing HPMCP; a precipitation step of precipitating the HPMCP by mixing the reaction product solution with water to obtain a suspension of the precipitated HPMCP; and a washing and recovery step of washing the HPMCP in the suspension and recovering the washed HPMCP. Further, there is provided HPMCP having yellowness at 20° C. of 10.0 or less, as determined in a 10% by mass solution of the HPMCP in acetone.

Provided is a method for producing HPMCP capable of reducing the average particle size of HPMCP particles to an intended range without a pulverization step. Specifically provided is a method for producing hypromellose phthalate, comprising an esterification step of reacting hypromellose with an esterification agent in the presence of a catalyst to obtain a reaction solution containing crude hypromellose phthalate, a precipitation step of mixing the reaction solution with water to precipitate the crude hypromellose phthalate, thereby obtaining a hypromellose phthalate suspension, a liquid removal step of removing a liquid from the hypromellose phthalate suspension with a centrifugal decanter to obtain liquid-removed hypromellose phthalate, and a drying step of drying the liquid-removed hypromellose phthalate.

Provided is a method for producing HPMCP capable of reducing the average particle size of HPMCP particles to an intended range without a pulverization step. Specifically provided is a method for producing hypromellose phthalate, comprising an esterification step of reacting hypromellose with an esterification agent in the presence of a catalyst to obtain a reaction solution containing crude hypromellose phthalate, a precipitation step of mixing the reaction solution with water to precipitate the crude hypromellose phthalate, thereby obtaining a hypromellose phthalate suspension, a liquid removal step of removing a liquid from the hypromellose phthalate suspension with a centrifugal decanter to obtain liquid-removed hypromellose phthalate, and a drying step of drying the liquid-removed hypromellose phthalate.

Provided is a method for producing HPMCAS capable of reducing the average particle size of HPMCAS particles to an intended range without a pulverization step. Specifically provided is a method for producing hypromellose acetate succinate, comprising an esterification step of reacting hypromellose with an esterification agent in the presence of a catalyst to obtain a reaction solution containing crude hypromellose acetate succinate, a precipitation step of mixing the reaction solution with water to precipitate the crude hypromellose acetate succinate, thereby obtaining a hypromellose acetate succinate suspension, a liquid removal step of removing a liquid from the hypromellose acetate succinate suspension with a centrifugal decanter to obtain liquid-removed hypromellose acetate succinate, and a drying step of drying the liquid-removed hypromellose acetate succinate.

Provided is a method for producing HPMCAS capable of reducing the average particle size of HPMCAS particles to an intended range without a pulverization step. Specifically provided is a method for producing hypromellose acetate succinate, comprising an esterification step of reacting hypromellose with an esterification agent in the presence of a catalyst to obtain a reaction solution containing crude hypromellose acetate succinate, a precipitation step of mixing the reaction solution with water to precipitate the crude hypromellose acetate succinate, thereby obtaining a hypromellose acetate succinate suspension, a liquid removal step of removing a liquid from the hypromellose acetate succinate suspension with a centrifugal decanter to obtain liquid-removed hypromellose acetate succinate, and a drying step of drying the liquid-removed hypromellose acetate succinate.

There is provided a method for producing hypromellose phthalate (HPMCP) which exhibits an excellent solubility when dissolved in a solvent, while suppressing formation of undissolved matter. More specifically, there is provided a method for producing HPMCP, including an esterification step of esterifying hypromellose dissolved in glacial acetic acid with phthalic anhydride in the presence of sodium acetate at a temperature of from 75 to 100 C. to obtain a reaction product solution; a cooling step of cooling the reaction product solution to 70 C. or lower; and a precipitation step of mixing the cooled reaction product solution with water of from 0 to 40 C. to obtain a suspension of precipitated HPMCP.

There is provided a method for producing hypromellose phthalate (HPMCP) which exhibits an excellent solubility when dissolved in a solvent, while suppressing formation of undissolved matter. More specifically, there is provided a method for producing HPMCP, including an esterification step of esterifying hypromellose dissolved in glacial acetic acid with phthalic anhydride in the presence of sodium acetate at a temperature of from 75 to 100 C. to obtain a reaction product solution; a cooling step of cooling the reaction product solution to 70 C. or lower; and a precipitation step of mixing the cooled reaction product solution with water of from 0 to 40 C. to obtain a suspension of precipitated HPMCP.