Items Specification Appearance White or off white powder Solubility Easy to dissolve in water Identification HPLC IR Water 3.0%～5.0% Heavy metals ≤20ppm Residue on ignition ≤0.1% Chiral impurities ≤1.0% Specific rotation -18.0°~-23.0°(C=1,water) Related impurities Total impurity≤1.0% Assay 98.0%~102.0% Conclusion Comply with In-house standard.