Patent ID: 6933380

Claim:
A low-residual-solvent excipient which has residual solvent of less than 3000 ppm; wherein said low-residual-solvent excipient possesses a water absorbing property which is characterized by the presence of a methoxy alkylcarboxyl (—CH 2 —O—RCOO − A + ) group in said excipient; wherein R is a lower alkyl group having 1-4 carbon atoms; wherein A + is Na + or K + ; and said low-residual solvent excipient being produced by mixing an excipient possessing said water absorbing property with a solvent/water solution which contains no more than 40% by volume of water to form a solvent/water/excipient mixture; filtering said solvent/water/excipient mixture to obtain a water-containing low-residual-solvent excipient; and driving said water-containing low-residual-solvent excipient to obtain said low-residual solvent excipient.