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Henning Gieseler

 

The importance of being small: miniaturisation of freeze drying equipment

Developmental activities for freeze-dried products are dictated by the limited…

18 August 2017 | By ,

Developmental activities for freeze-dried products are dictated by the limited availability and high cost of newly developed active compounds, and by Quality-by-Design requirements. Laboratory-scale freeze dryers used for formulation and process development show an excessive variety of designs and instrumentation concepts, making scale-up activities a challenge. The development of miniaturised…

Stabilisation of nanoparticles during freeze drying: The difference to proteins

The underlying concept for the stabilisation of proteins during freeze…

31 August 2011 | By Jakob Beirowski and Henning Gieseler, University of Erlangen-Nuremberg, Division of Pharmaceutics, Freeze Drying Focus Group

The underlying concept for the stabilisation of proteins during freeze drying is the formation of a glassy matrix in which the macromolecules remain isolated and immobilised. The concept relies on the so-called ‘vitrification hypothesis’ which assumes that the formation of an amorphous phase by lyoprotectants is mandatory to interact with…

Process Analytical Technology (PAT) in Freeze Drying: Tunable Diode Laser Absorption Spectroscopy as an evolving tool for Cycle Monitoring

The most important critical product parameter during a freeze-drying process…

12 December 2009 | By Stefan Schneid, Division of Pharmaceutics, Freeze Drying Focus Group, University of Erlangen-Nuremberg and Dr. Henning Gieseler, Division of Pharmaceutics, Freeze Drying Focus Group, University of Erlangen-Nuremberg

The most important critical product parameter during a freeze-drying process is the product temperature at the ice sublimation interface, Tp1. Once the product temperature in this area of interest exceeds the critical formulation temperature (typically denoted as "collapse temperature", Tc) during primary drying, a stepwise loss of the cake structure…

Application of DSC and MDSC in the development of freeze dried pharmaceuticals

Freeze drying of pharmaceuticals requires an adequate formulation design to…

3 December 2008 | By Jakob Beirowski, Pharmacist and Dr. Henning Gieseler, Assistant Professor, Division of Pharmaceutics, University of Erlangen-Nuremberg

Freeze drying of pharmaceuticals requires an adequate formulation design to prevent low-temperature, freezing and drying stresses. The goal is to achieve a final product with long storage stability and elegant appearance. To meet these specifications the product temperature must be controlled below the critical formulation temperature during the freeze drying…

A significant comparison between collapse and glass transition temperatures

Rational freeze-drying process design is based on a representative and…

29 September 2008 | By Eva Meister and Dr. Henning Gieseler, Division of Pharmaceutics, University of Erlangen-Nuremberg

Rational freeze-drying process design is based on a representative and accurate measurement of the critical formulation temperature. To avoid product shrinkage or collapse, it is indispensable to control the product temperature just below this key temperature during primary drying. Over the last decades, DSC was routinely used to determine the…

PAT for freeze drying: cycle optimisation in the laboratory

Freeze drying is generally known to be a time consuming…

25 January 2007 | By Dr. Henning Gieseler, PhD., Department of Pharmaceutics, University of Erlangen-Nuremberg

Freeze drying is generally known to be a time consuming and therefore expensive process. In order to lower costs during manufacturing, the effective cycle time must be reduced. This goal can be achieved by optimising a freeze drying cycle in the laboratory – in particular the primary drying phase. Applying…