Metformin Hydrochloride E.P

Sr. No. Tests Specification
1 Appearance White or almost 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) M.P 222 °Cto 226 °C
(c)TLC The principal spot in the chromatogram obtained with the test solution is similar in position colour and size to the principal spot in the chromatogram obtained with the reference solution.
(d) By Chemical A pink colour develops
(e) 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 Appearance of solution Solution S is clear and colorless
6 Sulfated Ash Not more than 0.1%
7 Heavy metals Not more than 10 ppm
8 Impurity F (Dimethylamine) Not more than 0.05%
Related substances(By HPLC)

a) Impurity A (Cyanoguanidine) Not more than 0.02%
  b) Any other impurity Not more than 0.1%
10 Assay (By Potentiometry, % w/w On dried basis) 98.5% to 101.0%
11 Residual solvent (By G. C.ppm)

a) Xylene Not more than 2170 ppm

b) Methanol Not more than 3000 ppm