Methods of crystal precipitation
AssigneeSumitomo Chemical Company, Limited
InventorsShigeya Yamazaki, Taichi Yoshikawa
Life of this patent
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Abstract
Crystals of paroxetine hydrochloride ½-hydrate are allowed to separate out by adding water to a solution or suspension comprising paroxetine hydrochloride and a polar organic solvent which contains no water or at most 60% by weight of water to adjust the water content to at least 70% by weight when crystals of paroxetine hydrochloride ½-hydrate are allowed to separate out in a water-containing polar organic solvent. Crystals of paroxetine hydrochloride ½-hydrate being not colored in pink can be allowed to separate out in the presence of hydrogen chloride when crystals of paroxetine hydrochloride ½-hydrate are allowed to separate out in water or a water-containing polar organic solvent.
Claims23
A method for allowing crystals of paroxetine hydrochloride ½-hydrate to separate out, wherein water is added to a solution or suspension comprising paroxetine hydrochloride and a polar organic solvent which contains no water or at most 60% by weight of water, to adjust the water content to at least 70% by weight when crystals of paroxetine hydrochloride ½-hydrate are allowed to separate out in a water-containing polar organic solvent.
A method for allowing crystals of paroxetine hydrochloride ½-hydrate to separate out, wherein hydrogen chloride is present when crystals of paroxetine hydrochloride ½-hydrate are allowed to separate out from a solution or suspension of paroxetine hydrochloride in which water or a water-containing polar organic solvent is used as a solvent, with the exception of the case where concentrated hydrochloric acid is added to an aqueous solution of paroxetine acetate.
Crystals of paroxetine hydrochloride ½-hydrate, moisturized with water or a polar organic solvent containing water, and being not colored in pink.
Crystals of paroxetine hydrochloride ½-hydrate, wherein the pH of a supernatant of the suspension prepared by suspending 1 g of the crystals in 10 g of distilled water is 3 to 6.
A process for preparing crystals of paroxetine hydrochloride ½-hydrate being not colored in pink, comprising dissolving crystals of paroxetine hydrochloride ½-hydrate being colored in pink in a solvent, and allowing the crystals to separate out, wherein the crystals are purified in the presence of hydrogen chloride in an amount at least equimolar with the paroxetine hydrochloride ½-hydrate.
Dependencies are inferred from the claim text.