University of Erlangen-Nuremberg

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Controlled nucleation in freeze-drying

22 October 2012 | By Henning Gieseler, Associate Professor at the Division of Pharmaceutics, University of Erlangen & CEO, GILYOS GmbH and Peter Stärtzel, Pharmaceutical Scientist, GILYOS GmbH

The stochastic nature of nucleation during the freezing step of the freeze-drying process has been regarded as a demerit in a process which is considered under rigorous control. The freezing performance of a product can impact its subsequent drying behaviour and the final product quality attributes. Hence, the idea to…

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

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…

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The determination of structural changes of biopharmaceuticals during Freeze-Drying using Fourier Transform Infrared Spectroscopyb

20 March 2009 | By Heiko A. Schiffter (University of Oxford), Sebastian Vonhoff (University of Erlangen-Nuremberg)

Peptides and proteins are powerful active therapeutic ingredients used in a wide variety of serious conditions and illnesses such as diabetes, arthritis or cancer. The application of these so-called biopharmaceuticals has been rapidly increasing since the middle of the 1990s, facilitated by improvements in modern recombinant DNA technology and biotechnological…

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

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…

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A significant comparison between collapse and glass transition temperatures

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…

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PAT for freeze drying: cycle optimisation in the laboratory

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…