Abstract: Provided are hypromellose acetate succinate (HPMCAS) which exhibits high solubility and can suppress generation of undissolved materials when dissolved in a solvent; an HPMCAS-containing composition; and a method for producing the HPMCAS. More specifically, provided are HPMCAS having a ratio of 2-position MS to 3-position MS of 1.2 or less, wherein the 2-position MS means a molar substitution of hydroxypropyl group by which a hydrogen atom of a hydroxyl group on 2-position carbon of each glucose unit of the HPMCAS has been directly replaced, and the 3-position MS means a molar substitution of hydroxypropyl group by which a hydrogen atom of a hydroxyl group on 3-position carbon of each glucose unit of the HPMCAS has been directly replaced; a composition comprising the HPMCAS and a solvent; and the method for producing the HPMCAS.

Abstract: 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.

Abstract: Provided are hypromellose acetate succinate (HPMCAS) which exhibits high solubility and can suppress generation of undissolved materials when dissolved in a solvent; an HPMCAS-containing composition; and a method for producing the HPMCAS. More specifically, provided are HPMCAS having a ratio of 2-position MS to 3-position MS of 1.2 or less, wherein the 2-position MS means a molar substitution of hydroxypropyl group by which a hydrogen atom of a hydroxyl group on 2-position carbon of each glucose unit of the HPMCAS has been directly replaced, and the 3-position MS means a molar substitution of hydroxypropyl group by which a hydrogen atom of a hydroxyl group on 3-position carbon of each glucose unit of the HPMCAS has been directly replaced; a composition comprising the HPMCAS and a solvent; and the method for producing the HPMCAS.

Abstract: An internal combustion engine includes, in addition to an LPL-EGR system, two water vapor separation film modules for fresh air and for EGR gas. One module 34 is connected to a pressure reducing pump 40 through a suction passage 38. Other module 36 is connected to a pressure reducing pump 44 through a suction passage 42. A condenser 54 that condenses water vapor that flows through the suction passage 38 is provided in the suction passage 38. A water tank 56 that temporarily accumulates condensed water that is discharged from the condenser 54 is provided on a downstream side relative to the condenser 54. The water tank 56 is connected to injectors 60 that inject water from the water tank 56 into intake ports of respective cylinders or into respective cylinders.

Abstract: An internal combustion engine includes, in addition to an LPL-EGR system, two water vapor separation film modules for fresh air and for EGR gas. A module for fresh air is provided in an intake passage between a connecting portion with an EGR passage, and an air cleaner. A module for EGR gas is provided in the EGR passage on an upstream side of an EGR cooler. The module is connected to a pressure reducing pump through a suction passage. The module is connected to a pressure reducing pump through a suction passage.

Abstract: Provided are HPMCAS powder having high solubility when dissolved in a solvent and being capable of suppressing generation of undissolved materials; and a method for producing the powder. More specifically, provided is hypromellose acetate succinate powder having an average ratio of L to D of from 2.0 to 3.0, wherein L and D mean maximum and minimum diameters of each particle, respectively. Also provided is a method for producing a hypromellose acetate succinate, comprising the steps of: dissolving hypromellose powder in a solvent, esterifying the dissolved hypromellose with succinic anhydride and acetic anhydride in the presence of a catalyst to obtain a reaction mixture, and mixing the reaction mixture with water to precipitate hypromellose acetate succinate, wherein the reaction mixture just before being mixed with the water has a viscosity of from 100 to 200 Pa·s.

Abstract: Provided are hypromellose acetate succinate (HPMCAS) which exhibits high solubility and can suppress generation of undissolved materials when dissolved in a solvent; an HPMCAS-containing composition; and a method for producing the HPMCAS. More specifically, provided are HPMCAS having a ratio of 2-position MS to 3-position MS of 1.2 or less, wherein the 2-position MS means a molar substitution of hydroxypropyl group by which a hydrogen atom of a hydroxyl group on 2-position carbon of each glucose unit of the HPMCAS has been directly replaced, and the 3-position MS means a molar substitution of hydroxypropyl group by which a hydrogen atom of a hydroxyl group on 3-position carbon of each glucose unit of the HPMCAS has been directly replaced; a composition comprising the HPMCAS and a solvent; and the method for producing the HPMCAS.

Abstract: There are provided a solution for spray drying having a high transmittance and markedly reduced generation of undissolved matter; and a method for producing a solid dispersion by using the solution for spray drying so that clogging with the undissolved matter is reduced and dissolution is improved. More specifically, there is provided a solution for spray drying comprising hypromellose acetate succinate (HPMCAS) having a hydroxypropoxy molar substitution of 0.40 or more, a solvent, and a drug. There is also provided a method for producing a solid dispersion comprising the step of removing the solvent from the spray drying solution.

Abstract: Provided is a composition for hot melt extrusion including a drug and hypromellose acetate succinate (HPMCAS) having a hydroxypropoxy molar substitution of 0.40 or more and a mole ratio of an acetyl group to a succinyl group of less than 1.6. Further, provided is a method for producing a hot melt extrudate including the step of hot melt-extruding a composition for hot melt extrusion including a drug and hypromellose acetate succinate having a molar hydroxypropoxy substitution of 0.40 or more and a mole ratio of an acetyl group to a succinyl group of less than 1.6, at a hot melt temperature of not lower than a melting temperature of the hypromellose acetate succinate or of not lower than a temperature at which both the hypromellose acetate succinate and the drug are melted.

Abstract: Provided are hypromellose acetate succinates (HPMCAS) for use as a hot-melt extrusion carrier having a volume average particle size (D50) of from 70 to 300 as measured by dry laser diffraction and a loose bulk density of from 0.25 to 0.40 g/cm3; and a hot-melt extrusion composition comprising the HPMCAS and a drug. Also provided is a method for producing a hot-melt extrudate including the steps of: hot-melting the hot-melt extrusion composition at a hot-melt temperature equal to or higher than a melting temperature of the HPMCAS, or at a hot-melt temperature equal to or higher than a temperature at which both of the HPMCAS and the drug become melt; and extruding the hot-melted composition.

Abstract: Provided are a composition for hot-melt extrusion which can be hot-melt extruded at a temperature lower than a conventional temperature and therefore free of heat-induced deactivation of a drug; and a method for producing a hot-melt extrusion product which is simpler than a spray-drying method. More specifically, provided is a composition for hot-melt extrusion including a drug and hypromellose acetate succinate (HPMCAS) having a hydroxypropoxy molar substitution of 0.40 or more. Also provided is a method for producing a hot-melt extrusion product including a step of hot-melt extruding a composition for hot-melt extrusion including a drug and hypromellose acetate succinate having a hydroxypropoxy molar substitution of 0.40 or more at a hot-melt temperature of melting temperature of the hypromellose acetate succinate or higher, or at a hot-melt temperature equal to or higher than a temperature at which both the hypromellose acetate succinate and the drug become melted.