Superiority:
Appearance White or yellowish white ,crystalline powder or colourless or almost colourless crystals
Solubility Slightly soluble in water ,very slightly soluble in ethanol(96%).It is freely soluble indilute mineral acids.
Identification A.IR IR spectrum is concordant with Methyldopa CRS.
B.Enantiomeric purity D-Methyldopa not more than 0.5%
Appearance of solution Not more intensely coloured than reference solution BY6 or B6.
Acidity (0.1M NaOH) Not more than 0.5ml/g.
Absorbance(on anhydrous basis) 122~137
Related substances Impurity A Not more than 0.15%
Impurity B Not more than 0.15%
Impurity C Not more than 0.15%
Unspecified impurities Not more than 0.05%
Total impurities Not more than 0.5%
Details:
Appearance White or yellowish white ,crystalline powder or colourless or almost colourless crystals
Solubility Slightly soluble in water ,very slightly soluble in ethanol(96%).It is freely soluble indilute mineral acids.
Identification A.IR IR spectrum is concordant with Methyldopa CRS.
B.Enantiomeric purity D-Methyldopa not more than 0.5%
Appearance of solution Not more intensely coloured than reference solution BY6 or B6.
Acidity (0.1M NaOH) Not more than 0.5ml/g.
Absorbance(on anhydrous basis) 122~137
Related substances Impurity A Not more than 0.15%
Impurity B Not more than 0.15%
Impurity C Not more than 0.15%
Unspecified impurities Not more than 0.05%
Total impurities Not more than 0.5%