Cefaclor EP Impurity HUAG9954SHKCefaclor EP Impurity H [EP Impurity](6R,7R)-7-[[(2R)-2-[[(2R)-2-amino-2-phenylacetyl]amino]-2-phenylacetyl]amino]-3-chloro-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid(6R,7R)-7-((R)-2-((R)-2-amino-2-phenylacetamido)-2-phenylacetamido)-3-chloro-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acidGlycinamide, D-2-phenylglycyl-N-(2-carboxy-3-chloro-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-en-7-yl)-D-2-phenyl-, (6R-trans)-