Medicines from space
Understanding and controlling polymorphism in crystallization for pharmaceutical production in space.
COMPANY
VARDA Space Industries
RESEARCH CENTRE
University of Limerick, Taighde Éireann Research Ireland, MACSI, SSPC.
PRODUCTIVE SECTOR
Chemical and Pharmaceutical Industry
Problem description
How does microgravity influence crystal growth and polymorphism, and why do otherwise identical pharmaceutical crystal manufacturing processes produce different crystal structures (polymorphs) on Earth and in space?
Challenges and goals
- Understand the interplay of gravity, sedimentation and crystallization;
- Predict crystal growth and polymorphism of a test molecule;
- Support development of in-space pharmaceutical manufacturing platforms.
Mathematical and computational methods
Crystallization was modelled by coupling nonlinear hyperbolic partial differential equations computing the evolving number of crystal polymorphs of each size with an ordinary differential equation for solute concentration. The method of characteristics is used to analyze moving shocks while a high-resolution Godunov-type method is used to obtain accurate numerical solutions.
The interplay between sedimentation and crystallization was modelled with coupled nonlinear ordinary and integro-differential equations. Asymptotic analysis is used to identify distinct physical regimes and provide simplified analytical solutions.
Results and Benefits
The framework provided insights on polymorph nucleation and the impact of gravity on growth and sedimentation processes relevant to pharmaceutical crystallization. The adopted methodology reduced simulation costs while preserving accuracy.
The models also revealed critical distinctions between concurrent and sequential sedimentation–growth regimes and explained how gravity intensity may alter crystallization pathways.
