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