Mathematical modelling for development, scale-up and optimization of lyophilisation

Lyophilisation (or freeze-drying) is an important unit operation of pharmaceutical, biopharmaceutical and food technology allowing drying of heat sensitive products at low temperature. Several research groups and industrial companies have developed, tested and published mathematical models of the primary and secondary drying based on physical laws. There is a need for lyophilisation models written in a modern, user-friendly programming language allowing fast parameter estimation, automatic graphical outputs and parametric sensitivity studies.

Lyophilisation models have been completely written and solved in the gPROMS language and are now available as model libraries in gPROMS FormulatedProducts. The webinar will briefly summarise the main principles and challenges (e.g. inhomogeneous drying) of lyophilisation and the physical and mathematical laws and procedures used for the models' formulation and solution. The main part of the presentation will focus on the introduction of the lyophilisation model library, examples of model usage for sequential evaluation of the model adjustable parameters (heat and mass transfer coefficients), and process scale-up.

Topics covered

In this webinar you will learn more about:

• Introduction: lyophilisation and lyophilisers
• Lyophilisation as a multi-scale process
• Inhomogeneous lyophilisation - a key challenge for development and scale-up
• Mechanistic models of lyophilisation
• PSE software for modelling of lyophilisation in a single vial
• Example: Workflow for development and calibration of a model for primary drying

Presenter(s)

Pavol Rajniak is a Principal Consultant in PSE's Formulated Products business group. He completed his MSc. (1977), PhD (1984) and DrSc. (2005) degrees in Chemical Engineering from Slovak Technical University in Bratislava. He worked as a teacher at STU (1977 - 1998), then as a researcher at Merck & Co. (1998 - 2014) in the USA and at the Research Center for Pharmaceutical Engineering (2014 - 2016) in Austria. Dr. Rajniak's main focus during the last 20 years has been mathematical and experimental modelling and scale-up of different pharmaceutical unit operations for sterile liquids and solid dosage drug manufacture. He is the author of 43 scientific papers with more than 500 references.