PURPOSE: To obtain powdery sodium hyaluronate of good water solubility at low cost by washing a precipitate of sodium hyaluroanate with a water-soluble organic solvent, removing residual water from it and drying the precipitate in vacuo.
CONSTITUTION: A water-soluble organic solvent is added to an aqueous sodium hyaluronate solution containing sodium chloride to precipitate sodium hyaluronate. The obtained precipitate is separated from the mother liquor, the residual water is removed from this precipitate, and the obtained precipitate is dried in vacuo to produce the purpose powdery sodium hyaluronate. Examples of the processes for separating the precipitate from the mother liquor include one comprising precipitating the precipitate and removing the supernatant from it, one comprising filtering the mother liquor containing the precipitate by suction or under pressure, and one comprising centrifuging it with a centrifuge.
SHINDO TORU
FUJII MASAHIRO
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