Lyotherm2 is a unique instrument for analysis of freeze drying formulations, comprising DTA and impedance analysis. Many formulations, particularly complex pharmaceutical or biotech compounds, contain a mixture of components with different crystallisation behaviours. At low temperatures, such products can undergo invisible changes that have profound implications for their long-term stability. Impedance analysis can provide an indication of molecular mobility within a frozen sample (Rey, 1999)*, while DTA allows determination of significant endothermic or exothermic events such as glass transitions, crystallisations and eutectic melting.
Lyotherm2 provides an integrated Differential Thermal Analyser (DTA) and newly-developed electrical impedance (Zsinφ) capability within one instrument. Lyotherm 2 has been designed to measure glass transition (Tg‘), eutectic (Teu) and melting (Tm) temperatures relevant to freeze-drying formulations.**
Building on the conventional “electrical resistance” analysis that has traditionally been used for identification of softening or eutectic melting points in frozen materials, the use of impedance analysis – and specifically the measurement of a derivative of impedance known as “Zsinφ” – can provide important information as to the behaviour of the frozen solute phase* which may not be identifiable using conventional analytical techniques. As a result of its unique design features, Lyotherm2 not only has the benefit of combining DTA and Zsinφ analysis within one instrument, but also comes in at a fraction of the cost of many DSCs.
Lyotherm2 is supplied fully validated against standard reference solutions. Installation and training by an experienced scientist is also offered as standard, including instruction on interpretation of results.
*L. Rey (1999) Glimpses into the Realm of Freeze-Drying: Classical Issues and New Ventures, In: Freeze-Drying/Lyophilization of Pharmaceutical and Biological Products, L. Rey & J. May (eds), Marcel Dekker Inc., pp. 1-30
**K. Ward and P. Matejtschuk (2010) The use of microscopy, thermal analysis and impedance measurements to establish critical formulation parameters for freeze-drying cycle development, In: L. Rey & J. May (eds.) Freeze-Drying / Lyophilization of Pharmaceuticals and Biological Products (3rd Edition), Informa Healthcare (New York / London), pp.112-135 (ISBN-13: 9781439825754)