Drug Substance Polymorph Conversion

Drug substance polymorph conversion describes thermodynamic transition between distinct crystal forms during manufacturing or storage. Metastable forms spontaneously convert to stable polymorphs compromising bioavailability. Nucleation and growth mechanisms determine conversion rates. Temperature and humidity accelerate conversion. Preventive strategies including formulation stabilisation impede conversion.

Analytical monitoring detects polymorph appearance. Kinetic studies predict conversion timelines. Thermodynamic stability assessment characterises polymorph relationships. Regulatory specifications mandate monitoring conversions. Manufacturing process control maintains target polymorph throughout shelf life. Emerging stabilisation technologies prevent unwanted transformations.