Fundamental Aspects Of Solvent Effects In Crystallisation Processes

Publication Reference: 
29-08
Author Last Name: 
Davey
Authors: 
Davey,Yeoh, Chiarella, Gillon
Report Type: 
ARR
Research Area: 
Particle Formation
Publication Year: 
2005
Publication Month: 
11
Country: 
United Kingdom

The aim of this project is to enhance our understanding of how solvents affect the polymorphic forms of compounds. Polymorphism is very important to the pharmaceutical industry as a compound’s polymorph can exhibit different physical properties, some more desirable than others. Being able to control which polymorphic form is nucleated is thus very useful.

To study the effects of solvent type on polymorphism, enantiotropic compounds will be used. These compounds have multiple polymorphs but the distinguishing feature about them is that there is a transition temperature where the solubilities of the polymorphs are equal. This transition temperature is constant regardless of the solvent type as at this temperature the free energies of the polymorphs are equal. This allows us to study the effects of solvent type by decoupling it from the effects of the supersaturation.

The work done in this first year is primarily aimed at identifying the compounds which are enantiotropic in nature, selecting a model compound, characterizing it and determining its exact transition temperature. Subsequently, we will perform experiments using different solvents at the transition temperature and measure both induction times and nucleation rate.