(6R,7S)-3-(HYDROXYMETHYL)-7-METHOXY-8-OXO-7-[[(THIOPHEN-2-YL)ACETYL]AMINO]-5-THIA-1-AZABICYCLO[4.2.0]OCT-2-ENE-2-CARBOXYLIC ACID (DECARBAMOYLCEFOXITIN);cefoxitin iMpurity A;Bisoprolol FuMarate IMpurity-k;Cefoxitin EP 8.0 Impurity A;Cefoxitin EP Impurity A