Cefadroxil monohydrate Imp.F (EP):(6R,7R)-7-[[(2R)-2-[[(2RS)-2-amino-2-(4-hydroxyphenyl)acetyl]amino]-2-(4-hydroxyphenyl)acetyl]amino]-3-methyl-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid.