Polymorphic Transformation of Pravastatin Sodium Monitored Using Combined on-line FBRM and PVM

摘要

Polymorphic transformation of pravastatin sodium in a mixture of isopropanol and water was studied by use of on-line FBRM and PVM. It is shown that the form A polymorph transformed to the stable polymorph, form B. It was speculated that in the transformation process there was an agglomeration and breakage phenomenon. The transformation mechanism was identified as solution-mediated phase transformation. Influences of temperature, solvent composition and stirrer speed on the transformation process were examined. It can be seen from the FBRM monitoring results that higher temperature, larger ratio of water to isopropanol and higher stirrer speed can increase the transformation process.