Test Items Specifications Results Appearance white to almost white crystalline powder White crystalline powder Identification IR HPLC Must conform to reference standard Must conform to reference standard Conforms Conforms Absorbance NMT0.02 0.008 Water NMT 2.0% 0.76% Residue on Ignition NMT0.1% 0.04% Heavy Metals NMT 0.001% ﹤0.001% Related compounds R-isomer Compound B Compound C Any other individual impurity Total impurities (excluding R-isomer) NMT 1.0% NMT 0.2% NMT 0.1% NMT 0.1% NMT 0.3% 0.60% 0.03% Conforms 0.04% 0.15% Residual solvents Ethyl acetate Dichloromethane Methanol N,N-Dimethylformamidc NMT 0.5% NMT 0.06% NMT 0.3% NMT 0.088% 0.20% Conforms Conforms 0.008% Assay (HPLC) 98.0-102.0% 99.4% Conclusion:It conforms to USP31.