2nd Annual Lyophilization for Biologicals January, 2012, Hotel Excelsior, Munich, Germany

Transcription

1 2nd Annual Lyophilization for Biologicals January, 2012, Hotel Excelsior, Munich, Germany Summary Looking to the future of lyophilisation we will have to see much more collaboration between formulation scientists and lyophilisation optimisation. Round table discussions highlighted the need for control both with solution and process to define nucleation conditions with coked flow and radiative aspects of equipment control providing insight to some scale up problems that needed careful understanding from production and formulation teams. Less commonly seen techniques may continue to grow Dynamic Mechanical Analysis and impedance analysis been illustrated for solution state analysis. Powder flow and morphological analysis been highlighted through topographical X-ray techniques including a small indication bulk drying was still conducted and could be useful to protein biological in varying vial dosing of final or intermediate products. Patrick Garidel Boehringer Ingelheim. The importance of lyophilisation an overview. Presented the specifics of freeze drying from protein protection to bond energy protection and reference to formulations that have a less well defined mode of action, Patrick provided an overview of the products commonly freeze dried across the international pharmaceutical market at present. Freezing drying was defined with reference to specific needs for controlled ice structure, monitoring of primary drying rates, and examination of the secondary drying desorption of the final powdered material. Going into specific examples of the Metalyse kit, Patrick covered specifics of water for injection designed into the package delivery system for reconstitutions. This included aseptic technique descriptions through the vial reconstitution process as well as reference to specific patient information leaflet examples. Summary of the years additions to the Glass and water substitution hypotheses were covered at a level suitable for the introduction to the meeting. A well illustrated introduction across the full field of pharmaceutical freeze drying in vial systems. Prof Dr Tudor Arvinte University of Geneva The importance of formulation in developing a stable lyophilisation product. (Representing - Therapeomic inc (Basel)) Presented his sizable experience across projects across the past decade. Enforcing the idea of process development to be realistic with regard to appearance as it does not always correlate with activity. Recombinant Hirudin (7KDa) anticoagulant activity launched in 1997 (Canyon) was used to demonstrate molecular interactions that are not water protein interactions but protein protein interactions that need protection. As a very stable biological it serves as an example of how damage can occur during lyophilisation in products that are thermally stable.

2 Salt concentration was described to induce damage to proteins with double concentration systems providing a useful challenge and model to trial protein stability with during formulation development. High throughput screening available to the group had been used in this way since 1997 in developing stable formulations for several distinct lyophilised cakes with several thousand iterations performed. ILARIS was used as an example to illustrate the importance of ph optimisation using differing buffers (concluding with histidine) to first show stabilisation in solution but successfully extending to the lyophilised state. Stressing the importance of activity on reconstitution and not to reflect on the direct appearance of a formulation Tudor concluded his talk by stressing maximum stability in the solution state should most definitely be included in the requirements prior to lyophilisation. This was a key indicator that there is need for formulating solutions both for the solution state as well as the ability to process to the powdered state. Paul Matejtschuk National institute of biological science UK Use of thermal analysis to identify critical transition temperatures in the frozen and dried state. Director of ISLFD & Specialist interest group for PPA. Paul had an interesting approach to freeze drying on a commercial but small scale. Discussing thermal analysis and freeze drying microscopy his talk further developed to include the less used Impedance analysis and dynamical mechanical analysis. Electrical resistance an older technology still used within the freeze drier both during production and at a practical research level. Impedance analysis has extended this forward to allow formulation development to define states of change during the freezing process. Illustrated from the technology launched by Biopharma Technology (UK) previously developed by the late Professor Louis Rey (Geneva, Switzerland). Expressing regulatory aspects particularly from within the EU are allowing product control inside defined limits providing much greater acceptable process variation. Low concentration filling atypical of a commercial environment but of particular interest to diagnostic users who would demand conservation of initial low activity systems was assisted by a bulking protein (albumin) to prevent adhesion to the glass surfaces of vials or ampoules. Freeze drying microscopy illustrated the synergy between the impedance techniques and freeze drying microscope. Indicating that events separated from collapse do reproducibly occur at lower temperatures. Dynamic mechanical analysis (DMA) was defined relating stress and strain. Calculating tan Delta DMA was capable of providing glass transitions. Noting its historical significance in the food industry and its previous limited application to freeze drying processes it was of particular note as its applications and level of development were already significant. Stressing the importance of a 1 hertz frequency as a requirement to stop analysis Paul provided practical examples across a number of biological systems.

3 Providing impedance analysis for Tetanus Toxoid noting changes of significance at -40 degree Celsius. Freeze drying microscopy was highlighted as very quick hour long process that would provide good looking product but that had previously been illustrated as not always indicative of activity gain or loss. Of note was the comments of how differential scanning calorimetory for use with some mixed biological materials with practical experience was difficult to interpret and had potential to over extrapolate its true meaning. Gerhard Schilder Advancements in the design of large scale freeze drying systems (Hof Sonderanlagenbau GmbH) Moving quick to the larger 75m2 shelf area sector Gerhard explained the engineering aspects of drying. Illustrating the equipment limiting factor referred to as choked flow. Gerhard clearly expressed a need to know your scale up process to include the research machines importantly to the final production machine. Choked flow at the condenser was shown as well as computer dynamics of vial and stopper systems that may result in variety sublimation rates. Short connections, large openings of condenser were needed for best case equipment design. Computation fluid dynamics was used to illustrate that commercial machines just did not produce flow rates suitable for sublimation that had been optimised with certain scale up processes. A system of active thermal radiation shielding was illustrated which was capable of control of the edge affects during freeze drying. This had recently finished trials and patented for future use. Flexible shelf package adjustment was illustrated providing a variety of shelf separation formats for differing vial formats. This was capable of operation during the cycle but also assisted with cleaning through a tilting process with further implications to any stoppers that may stick to an upper surface at closure. The need for further Mathematical modelling tools was highlighted. Pirani gauge, capacitance combinations were used to illustrate primary drying end point examples. Reinforcing that the pressure rise test could be seen in patents dating 1959 Gerhard expressed that work still would need to continue in this area as end stage user trends were still requesting pressure rise sensing systems. Wireless temperature sensors from a variety manufactures were illustrated with battery, wire bound and battery free. Care was taken to express the limitations of abnormal nucleation, the size and mass transfer consequences of such sensors of a variety of shapes and sizes. Distance for signal transfer inside essencially a faraday cage was expressed. Regulatory access of data interruption should be considered if processes or noise could disrupt particularly the wireless system. Silicone oil contamination was monitored with mass spectroscopy during the production process. Individual components were detected during processing as well as linked to the potential for active water measurement.

4 2 stage compressors are more popular, been legally excepted more readily in Europe with tuneable refrigeration been much more possible. Davide Fissore Examining a model-based framework for recipe design and optimisation (politecnico di torino) Focused on the robustness of cycles developed with use of an experimental model and how this may be implemented during scale up. There are several mathematical simulations available to the market. It is essential that the number of parameters is realistic and that each is measurable. With relatively simple mathematics Davide explained the potential for extraction of variables from small vial batches. Heat transfer coefficient (Kv) vials vary depending on location. These are related to radiative heat transfer to the product. Determining the heat transfer coefficient though thermocouple was illustrated as relatively simple and performed with 2-3 scale samples. Kv measured through the pressure rise test was illustrated then correlated with theoretical data. A simple two design space system was described but with a remarkable correlation to the experimental data for the formulation system examined. The approaches are been used for regulatory submission and such design space is justifiable to the regulators. Dr Andrea Hawe - Coriolis Pharma - Rational lyophilisation cycle design to prevent protein aggregation. Process technology was expressed to be only part of the story and that formulation science is vital to the picture. Stable in the solution state does not always transfer to stable in the dried state, Acetate buffer was given as a key example. Sample thief because of a useful way as monitoring along with single shelf closure was in use heavily at Coriolis. Focusing on protein aggregation. Colloidal instability (CI) and conformational stability (CS) were discussed. CS allows lyoprotective systems to be looked at, while CI is developed with focuses on ph. Vibrational mass determination was highlighted as a new technique in protein aggregation science of use in formulation development for lyophilisation. Examining IGg particles Andrea examined the size observed through differing techniques; light scattering, coulter counting and microflow images. Refractive index of particles verse particles was highlighted as a potential for poor performance of light scattering techniques.

5 Through use of case studies of double concentrated mannitol systems moisture level control was shown to be important. Drawing her conclusions using multiple techniques of protein aggregation Andrea concluded that both formulation and process controlled lyophilisation are demanded by modern lyophilisation requirements. Jorg Lumkemann - (F. Hoffmann-La Roche) Optimising freeze drying cycles with TDLAS (tunable Diode Laser Absorption Spectroscopy) Jorg expressed current techniques industry uses to control freeze drying. How the definitions for this type of technology may be reached for product specification. Barameteric techniques Pressure rise test Parani manometeric divergence Scales for active measurement of product Aluminu oxide sensors Cable bond NIR Mass spectroscopy of the process gas Laser spectroscopy Using one or more of these may be used to accommodate transfer between sites or machines. However, many of these measurements are surrogates for the actually value only few of them been relevant to the whole batch. Providing a specification for a potential system; All vials need to be represented Technique had to be Sensitive Deployable Integrated to SPS of the freeze drier Inform the decision to switch primary to secondary cycle Sterilisable with steam And Reliable Roche s choice was to deploy point light Laser Doppler technology. Secured through a two flange GMP approved system with FDA certification for the required chamber windows it is minimally intrusive to the system. The laser meter requires only the path length to be calibrated and fitted. Drift and failure has not been seen in a five year period. The only point the laser spectroscopy is blind during the freezing process as without the vacuum as it is outside its measuring range. Instrumental cost is 26000Euro. Harald Beese (Fraunhofer Institute for material and Beam Technology IWS) Focusing on a detailed explanation of the electronic approach behind the technology. Harald described

6 the mathematical basis behind the partial pressure determination. Positioning the laser with an optical view point using a single pass length or reflector the vapour pressure of water vapour could be determined. To apply the Doppler method Harald had customised a 2 beam technology with lasers travelling in opposite directions to cross at a fixed point. Variations at the zero point in the laser signal allowed calculation of the mass flow. An industrially trialled technique the extension of the Doppler technique is capable of monitoring primary drying within an adapted freeze drier capable of been steam sterilised. Back reflection must be protected against depending on the type of reflector or path window used. Successfully scaling up the manufacture of lyophilised biological Yves mayeresse. GSK Biologicals. Starting the second day of conference with a little of the history then moving quickly to the modern problems. Looking at viruses models with a discussion of stabilising specifically for these agents, Yves then took us through cost efficiently to amorphous and crystalline mixtures including crystallisation and re-crystallisation. Vial shape and contact and quality was expressed as a consideration for clinical stages, indicating a preference to maintain these through formulation. Stoppers as part of the drug file should be maintained through development. Stressing the need for scale up to be optimised for the next industrial lyophiliser and not to be simply the present machine. Consideration was given to longer or even safer cycles during development optimisation can be done at a later point. It was noted however to be difficult to change the cycle after phase 1 clinical trials. After these trials both internally and with regulators there is a wish for looking back to clinically bridge studies often cause the loss of years. It is therefore important to choose optimisation at the correct points in the timescale. Considering the concerns for quality assurance and the potential sources of variation. Concerns over silicone in the condenser vs. gas based systems. Radiations from upper shelves as well as the freeze drier wall were considered. Heater powder variations. Inlet and outlet regulation within the cooling/ heating system. Compressor temperature may be changed by cooling water which may cascade to the final product. Yves described his use of a microbalance for measurements during sublimation. Freezing was described with relevance to potency and aspects of amorphous nature. ph sample indication was used to monitor visually during the freezing process. Some links to the processing of eutectic systems. Concluding scale up is not empirical any more. PAT tools are becoming better used and allowing dependent variable modelling and monitoring. These should produce more advanced mathematical models in the future.

7 Stefan Schneid Applying PAT to your lyophilisation process. (syntacol GmbH) Product resistance was linked to the solute concentrations and then linked across to the annealing process and freezing rates of the process machine. The influences of microcollaspe on this data were indicated indicating its usefulness as this none visual type of collapse could not easily be monitored with visual inspection. Discussion of existing sensors limitations and benefits of the thermocouple and PT100 were discussed. Vapour pressure resistance was detailed from a simple mathematical approach to illustrate product and stopper resistance including sublimation temperature. TDLAS and its use at Syntacol was described including further details on integration to the freeze dryer system. This system used the dual laser detector system taking advantage of the Doppler affect. Shelf mapping demonstrated for heat transfer relationships was given. PAT is gaining importance as we move forward it will be important to see these added to research driers as well as manufacturing scale processes. Patrick Garidel (Boehringer Ingelheim) questioning the author wanted to know which single choice he would make. No single technology is good enough, but it would be preferential to see devices that can be used in scale up and research with high levels of reproducibility. Edward Trapper (lyophilisation Technology, INC. USA) queried the use of mass spectroscopy and the absence from the presentation, Stefan (syntacoll) commenting that the mass spec is more versatile but this technology would be useful in scale up and across a multitude of machines but he did not feel it suitable for single installations to the specific machines, been more useful for trouble shooting leaks and other problems across a range of machines because of its expense. New insights into the specific surface area analysis of freeze dried pharmaceuticals. Peter Startzel (university of Erlangen-Nuremberg) Mercury porosimetry was discussed to quantify specific surface area. Discussed to include the pore size information including limitations such as 3nm methodology which may also introduce collapse of a product to cavities and make specific formulations difficult to process. Gas absorption methodology. Gas absorption at a surface of a material while at cryogenic temperatures was examined. Looking at the absorption isotherm this technique has been used to examine 2nm pores. This was discussed in detail including UPAC classification of freeze dried materials within the size range of macropores or non porous material.

8 Appropriate gas section including krypton and nitrogen was used to discuss the uncertainty of measurement. Kryton was the gas of choice for freeze dried materials. Utilising a QbD Approach with lyophiisation processes. Paul van Herpen (Netherlands vaccine Institute (RIVM)) Material attributes, eutectic, collapse, solidification temperatures control the critical processing parameters all part of the inputs to a good QbD approach. Following a full discussion of all the critical processing steps for a freeze drying of bacterial samples the freezing and dehydration steps are discussed to include the aspects of freeze concentration and osmotic pressure changes. The motivation for theses controls were the FDA acceptance of variation through a QbD approach which would allow manufacturers to accept variation within a batch. Illustrating crystal nucleation changes through different cooling rates Paul with an extensive sample count was able to demonstrate through data and a visual presentation the route through the stages of freezing concluding its inconsistency. Feeling the freezing state is of particular importance to the drying environment Paul concluded his presentation. In-line Raman and NIR Spectroscopic Monitoring of Protein Secondary Structure During Freeze-Drying. Sigrid Pieters (University of Ghent) Ghent University was in the process of examining Near infra red (NIR) for inline monitoring of protein formulations. Specifically looking at diffuse reflection, Yves looked at hydrogen bonding levels across the model IGg protein to reflect on NIR as well as Mid infra red. NIR been insensitive to specific protein structures but also been interfered with by water. It had been seen during secondary drying its efficiency was completely obscured by the presence of water. Monitoring protein unfolding by the number hydrogen bonding could be found within the mid infra red range. Inline experiments using near infrared were positioned with fibre optic lines to be used for monitoring during secondary drying. Lyoprotectant activity of sucrose interactions was noted to be at lower frequency and may be of further note. There are clear limitations to the positing of probes and the point source effect of the measurements is a clear limitation. Raman Spectroscopy using laser light to excite molecules as it induces a dipole moment. Focusing on stokes and anti stokes radiation the technique is fast, non invasive and without the problems associated with water noted for NIR. High protein concentration would be required but currently limitations would not allow concentrations to be analysed needing a more enhanced Raman technique. Probe insertion into the freeze drier has proved problematic with potential damage to the probe from the vacuum.

9 Principles component analysis was used with limited sample numbers to correlate NIR. But it still showing clear correlation with the monitored properties from NIR analysis. Optimisation of freeze drying cycles of commercial formulations. Rim Daoussi (Pfizer Global Supply) Sublimation kinetics for mass transfer and vapour resistance calculations through different PAT technologies was discussed. Particular interest was paid to calculations of Kv and its relationship to abnormal formulations and how these may be compensated for by correct measurements of the production environment. Freeze drying Further processing Powder Flow Properties. Andrew Ingham. (Aston University, UK) Ending the conference properties of bulk powder flow for amorphous and crystallised systems was presented. Using angle of repose, compressibility factors and pointing towards correlations with micro Xray CT for characterising powder flow the author was able to point to some of the future aspects that may take freeze drying away from vial systems and back towards tray bulk freeze drying of both excipients and final products. Outlining the main useful techniques for lyophilisation powder characterisation powder flow for several model systems was shown to be poor in almost all situations however directions for the future were indicated and the technology been exploited was critically evaluated.