Trimethoprim

Trimethoprim (INN) is a bacteriostatic antibiotic mainly used in the prophylaxis and treatment of urinary tract infections. It belongs to the class of chemotherapeutic agents known as dihydrofolate reductase inhibitors. Trimethoprim was formerly marketed by GlaxoSmithKline under trade names including Proloprim, Monotrim and Triprim; but these trade names have been licensed to various generic pharmaceutical manufacturers. In clinical use it is often abbreviated TRI or TMP; its common laboratory abbreviation is W. Items Standard Results Appearance Whiteoryellowish-whitepowder Whitepowder Solubility Veryslightlysolubleinwater, slightlysolubleinalcohol. Veryslightlysolubleinwater, slightlysolubleinalcohol. •Identification A:Meltingpoint 199-203 201.0-201.4 B:Specificabsorbance Max.287nm:240-250 243 C:IR-spectrum Complieswithreferencespectrum Complieswithreferencespectrum D:Chemicalreaction Greenfluorescenceat365nm Greenfluorescenceat365nm Appearanceofsolution Notmoreintenselycoloredthan ReferenceSolutionBY7 LessintenselycoloredthanreferencesolutionBY7 Relatedsubstances MethodAbyHPLC: ImpurityF ≤0.1% 0.05% Anysingleimpurity ≤0.1% <0.1% Totalimpurities ≤0.2% <0.2% MethodBbyHPLC: Anysingleimpurity ≤0.1% <0.1% Totalimpurities ≤0.2% <0.2% Heavymetals ≤20ppm < 20ppm Residualmethanol ≤3000ppm Notdetected ResidualDMSO ≤5000ppm Notdetected Residualaceticacid ≤5000ppm Notdetected ImpurityK(aniline)byGC ≤5ppm Notdetected Lossondrying ≤0.5% 0.3% Sulphatedash ≤0.1% 0.02% Assay 98.5-101.0% 99.71% Particlesize 100%pass300mesh 100%pass300mesh