Metformin Hydrochloride USP

Sr. No. Tests Specification
1 Appearance White crystals
2 Solubility Freely soluble in water, slightly soluble in Alcohol, practically insoluble in Acetone and in Methylene Chloride.
3 Identification By:
(a) IR IR spectrum of test preparation should be concordant with that of the Metformin Hydrochloride reference standard or working standard preparation.
(b) Reaction of chloride It gives chloride test
4 Loss on Drying at 105 °C for 5 hrs. Not more than 0.5% w/w
5 Residual on ignition Not more than 0.1%
6 Heavy Metal Not more than 0.001%
7 Related compounds (By HPLC)
a) Related compounds – A (1-Cyanoguanidine) Not more than 0.02%
b) Any other impurity Not more than 0.1%
c) Total impurity Not more than 0.5%
8 Assay (By Potentiometry, % w/w On dried basis) 98.5% to 101.0%
ADDITIONAL TEST
9 Residual solvent (By G. C.ppm)
a) Xylene Not more than 2170 ppm
b) Methanol Not more than 3000 ppm