Microscopy & Microtechniques

  • Report on the Work of Dr Henning Gieseler in the Field of Pharmaceutical Freeze Drying
    A Linkam FDCS196 stage mounted on a ZEISS optical microscope located in the GILYOS laboratories. Dr Henning Gieseler founded the company and is their CEO. (photograph courtesy of GILYOS: www.gilyos.com).

Report on the Work of Dr Henning Gieseler in the Field of Pharmaceutical Freeze Drying

Jan 25 2018 Read 1578 Times

Dr Henning Gieseler leads the Freeze Drying Focus Group (FDFG) in the Division of Pharmaceutics at the Friedrich-Alexander University (FAU) Erlangen-Nuremberg. He started his research in this area in 2006 after first coming across freeze drying microscopy (FDM) during his post doc at the University of Connecticut in the USA where he used a Linkam FDSC196 stage. This led in the following years to a collaboration with Linkam on the development of innovative instrumentation dedicated to improve freeze drying characterisation methods.

The main research goal is to have a representative measure of the temperature point (or region) where the product starts to undergo structural (morphological) changes during primary drying of a freeze drying cycle. These changes can be visually detected, in form of ‘shrinkage’ or ‘collapse’. It is essentially the point where a (rigid) glassy system starts to flow (decrease in viscosity). This temperature point is specific for every single formulation in the world. Product defects or imperfections, such as collapse, are of regulatory concern and might impede pharmaceutical quality parameters. Conventional FDM allows the determination of the so called ‘onset of collapse temperature, Toc’. This measurement is performed using 2-3 µL of liquid placed between two glass cover slips. This experimental setup reflects a 2D measurement, i.e. on the pore size level. In other words, during freeze drying, the product would not show the expected level of collapse when exposed to the same process temperatures applied during the FDM measurement. In order to get a more complete understanding of product behaviour, a scale-up of the measurement was required to cover the full perfomance range and test product behaviour at larger volumes when in a commercial vial. This would then be a 3D experiment which would be more reflective of a typical freeze drying cycle. Together, these complementary techniques allow a better understanding of formulation in the frozen state and of the scale up factors (from 2µL to 5 mL) which allow improved process optimisation.

The work over the last two years has led to the production of Linkam’s Freeze Drying Vial System (FDVS). This development came in part from the excellent work of one of Dr Gieseler's PhD students, Zixin Huang. Dr Gieseler comments on the collaboration: “Our work with Linkam has enabled the release of a cost-effective solution with a small footprint for freeze drying optimisation. We have also seen that Linkam’s new Optical DSC performs a complementary role in the process.”

Reader comments

Do you like or dislike what you have read? Why not post a comment to tell others / the manufacturer and our Editor what you think. To leave comments please complete the form below. Providing the content is approved, your comment will be on screen in less than 24 hours. Leaving comments on product information and articles can assist with future editorial and article content. Post questions, thoughts or simply whether you like the content.

Post a Comment




Digital Edition

International Labmate July 2019

July 2019

In This Edition Mass Spectrometry & Spectroscopy - 67th ASMS Conference on Mass Spectrometry and Allied Topics - Modular MS Bench System with Integrated Gas Supply for Sciex LC-MS/MS Unveile...

View all digital editions

Events

AACC Annual Meeting & Clinical Lab Expo

Aug 04 2019 Anaheim, CA, USA

M&M 2019

Aug 04 2019 Portland, OR, USA

DXC 2019

Aug 05 2019 Lombard, IL, USA

ACS National Meeting & Expo, Fall 2019

Aug 25 2019 San Diego, CA, USA

Microscopy Conference 2019

Sep 01 2019 Berlin, Germany

View all events