Assay (acidimetric; calculated on dried substance):
99.5 - 100.5 %
Assay (HPLC, calc.on dried substance):
98.0 - 102.0 %
Identity:
passes test
Appearance of solution (10 %; ethanol 96 %):
passes test
Chloride (Cl):
≤ 0.0100 %
Sulfate (SO₄):
≤ 0.0200 %
Related substances / HPLC (EP) (4-Hydroxybenzoic acid):
≤ 0.1 %
Related substances / HPLC (EP) (4-Hydroxyisophthalic acid):
≤ 0.05 %
Related substances / HPLC (EP) (Phenol):
≤ 0.02 %
Related substances / HPLC (EP) (Largest unspecified impurity):
≤ 0.05 %
Related substances / HPLC (EP) (Sum of all impurities):
≤ 0.2 %
Related substances / HPLC (USP) (4-Hydroxybenzoic acid):
≤ 0.1 %
Related substances / HPLC (USP) (4-Hydroxyisophthalic acid):
≤ 0.05 %
Related substances / HPLC (USP) (Phenol):
≤ 0.02 %
Related substances / HPLC (USP) (Largest unspecified impurity):
≤ 0.05 %
Related substances / HPLC (USP) (Sum of all impurities):
≤ 0.2 %
Residual solvents (ICH Q3C):
excluded by manufacturing process
Sulfated ash:
≤ 0.05 %
Loss on drying:
≤ 0.5 %
