Inspection items 

 Enterprise Standard of our company

USP37 

 Appearance

 A white or almost white crystalline powder. 

 -

 Solubility

 Soluble in water, practically
insoluble in ethanol, methanol.

- 

Optical rotation

+46.0°~+50.0°

+46.0°~+50.0° 

 Water

12.0%~15.0% 

10.0%~16.0% 

 Clarity and colour

Solution is not more intensely turbid than reference suspension 1, and not more intensely coloured than reference solution Y1.

- 

 Trasmittance

≥ 95.0% 

- 

 Chloride

≤ 0.01% 

≤ 0.01% 

 Ammonium

≤ 0.02% 

≤ 0.02% 

 Iron

≤ 0.001% 

≤ 0.001%  

Sulfate 

≤ 0.02% 

≤ 0.02% 

 Arsenic

≤ 0.0001% 

- 

 Residue on ignition

≤ 0.10% 

≤ 0.10% 

 Related substances
(HPLC)

Tyr (Impurity A)≤ 1.5% ;
 Gly (Impurity B)≤ 1.0% ;
 Cyclo (gly-tyr)(Impurity C)≤ 0.2% 

 Tyr ≤ 1.5% ;
 Gly ≤ 1.0% ;
 Cyclo (gly-tyr) ≤ 0.2%;
Pivaloyl-L-tyrosine ≤ 0.1%;
Gly-gly-tyr ≤ 0.3%