Purification of Erythromycin by Antisolvent Crystallization or Azeotropic Evaporative Crystallization

Crystallization plays an important role in separation and purification of the antibiotics. And it is also an indispensable step in preparation of pharmaceuticals with biological activities and specific crystal form. As the last step in purification, crystallization determines the puri‐ ty, crystal habit, granularity and its distribution as well as pharmacologic effect, biologic ac‐ tivity and product stability [1], which are actually dependent on specific mechanism for its processes and operational conditions. So it’s necessary to study thermodynamics, kinetics and conditions of crystallization process, which helps increase the yield and reduce cost.