Antibiotic crystalline epimer, its preparation and pharmaceutical composition containing it.

摘要

The diamonium salt of the oxa- beta -lactam antibiotic of the formula
<CHEM>
wherein the chiral center of the alpha -carboxy-p-hydroxy-phenylacetyl side chain has the D-configuration in crystalline form substantially free of the L-diammonium salt. This invention also relates to a process for preparing the crystalline D-diammonium salt of the above formula.