10.21253/DMU.11988519.v1 Geoff Smith Geoffrey Smith Freeze-drying process optimization using through vial impedance spectroscopy. EPSRC EHDA Network International Pharmaceutical Technology Conference, November 4, Leicester, United Kingdom De Montfort University 2020 lyophilization freeze-drying through-vial impedance spectroscopy TVIS Pharmaceutical Sciences 2020-04-29 10:17:06 Presentation https://figshare.dmu.ac.uk/articles/presentation/Freeze-drying_process_optimization_using_through_vial_impedance_spectroscopy_EPSRC_EHDA_Network_International_Pharmaceutical_Technology_Conference_November_4_Leicester_United_Kingdom/11988519 Cite as : <div>Smith, G. (2016) Freeze-drying process optimization using through vial impedance spectroscopy. Podium presentation at EPSRC EHDA Network International Pharmaceutical Technology Conference, November 4, Leicester, United Kingdom<br></div><div><br></div><div>Scope of the presentation:</div><div><div>The talk starts with an introduction to freeze-drying and the design space for the process, then provides an introduction of Through Vial Impedance Spectroscopy (TVIS) Technology</div><div><br></div><div>The rest of the talk is then devoted to applications for TVIS in the determination of two important process parameters: </div><div>➢ Heat transfer coefficient through the vial base KV</div><div>➢ Dry layer resistance which impedes the of water vapour sublimation R<sub>P</sub></div></div><div><br></div><div>The dry layer resistance was calculated for a 2% solution of protein. This substance presents on interesting TVIS spectrum with separate contributions from the dielectric relaxation of ice and from another relaxation process associated with he unfrozen fraction.</div>