The invention belongs to the technical field of
pharmacy, and relates to a preparation method of
ampicillin sodium. The preparation method comprises the following steps: mixing
ampicillin acid and
sodium type cation exchange resin in water according to a certain proportion, stirring and dissolving, filtering to obtain an
ampicillin sodium solution, and concentrating and freeze-
drying to obtain the
ampicillin sodium with the quality meeting the standard. According to the preparation method, the
raw material ampicillin acid does not need to be dehydrated, any
organic solvent does not need to be used, the ampicillin acid can be directly converted into the
ampicillin sodium only through the cation exchange resin, the
process design is innovative, the operation is simple and convenient, the
energy consumption is low, and the obtained
ampicillin sodium product is high in quality and stable.