CAS number： 738-70-5
Molecular formula： C14H9Cl3N2OS
molecular weight： 359.6581
Chemical structure：
| Product name: | Trimethoprim | |
| Expiry Date: | Fiveyears | |
| Inspection Standard: | EP7.0 | |
| Tests | Standards | Results |
| Appearance | White or yellowish-white powder | White powder |
| Solubility | Very slightly soluble in water, slightly soluble in alcohol. | Very slightly soluble in water, slightly soluble in alcohol. |
| Identification | ||
| A: Melting point | 199-203℃ | 199.5.0-200.6℃ |
| B: Specific absorbance | Max.287nm: 240-250 | 246% |
| C: IR-spectrum | Complies with reference spectrum | Complies with reference spectrum |
| D: Chemical reaction | Green fluorescence at 365nm | Green 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 | ≤3000ppm | Not detected |
| Residual DMSO | ≤5000ppm | Not detected |
| Residual acetic acid | ≤5000ppm | Not detected |
| Impurity K(aniline) by GC | ≤5ppm | Not 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 | ||
