Trimethoprim

CAS number: 738-70-5

Molecular formula: C14H9Cl3N2OS

molecular weight: 359.6581

Chemical structure:

Product name:    Trimethoprim
Expiry Date: Fiveyears
Inspection Standard: EP7.0
TestsStandardsResults
AppearanceWhite or yellowish-white powderWhite powder
Solubility

Very slightly soluble in water, 

slightly soluble in alcohol.

Very slightly soluble in water, 

slightly soluble in alcohol.

Identification
A: Melting point199-203℃199.5.0-200.6℃
B: Specific absorbanceMax.287nm: 240-250246%
C: IR-spectrumComplies with reference spectrumComplies with reference spectrum
D: Chemical reactionGreen fluorescence at 365nmGreen fluorescence at 365nm
Appearance of solution

Not more intensely colored 

than Reference Solution BY7

Less intensely colored than reference solution BY7
Related substances
Method A by HPLC:
Impurity F≤0.1%0.02%
Any single impurity≤0.1%<0.1%
Total impurities≤0.2%<0.2%
Method B by HPLC:

Any single impurity≤0.1%<0.1%
Total impurities≤0.2%<0.2%
Heavy metals≤20ppm<20ppm
Residual methanol≤3000ppmNot detected
Residual DMSO≤5000ppmNot detected
Residual acetic acid≤5000ppmNot detected
Impurity K(aniline) by GC≤5ppmNot detected
Loss on drying≤1.0%0.21
Sulphated ash≤0.1%0.08%
Assay 98.5-101.0%99.89%
Conclusion : Complies with EP7.0