The invention belongs to the technical field of
medicine crystallization processes, and particularly relates to a
crystallization process of small-particle-size
azithromycin fumarate with low
solvent residue. In the prior art,
azithromycin fumarate is crystallized in an
alcohol solvent, which is often accompanied by the residue of an
ethanol reagent. The invention provides a
crystallization process of
azithromycin fumarate, which comprises the following steps: feeding part of
fumaric acid into azithromycin, adding an azithromycin fumarate
seed crystal, carrying out ultrasonic induced crystallization, continuing feeding
fumaric acid, and carrying out vacuum concentration for constant-temperature
crystal growing. According to the azithromycin fumarate
crystal prepared by the method, the
particle size distribution range is 15-30 microns, the
ethanol residue is also reduced to 0.5% or below, and the azithromycin fumarate
crystal can be directly used for preparation
processing, does not need to be purified again, and is a
raw material medicine product with high quality and good
economic benefits.