Formula V 19 - 22 November Potsdam, Germany
' Formulating opens the way for tailoring products for specific applications and combining components with often contradicting properties. Formulation science and technology is a core discipline for industries and applications like home care, cosmetics, plant protection and coatings but also of emerging importance in fields like electronics, composite materials and biomedical technology.'
Poster contributions
Accelerated screening of formulations towards freeze-thaw stability
T. Sobisch, D. Lerche, L.U.M. GmbH, www.lum-gmbh.com
Rudower Chaussee 29, 12489 Berlin, Germany
The formulation of dispersion based products as well as process development/monitoring and quality assurance require efficient and objective analytical tools for shelf life prediction and stability determination. Freeze/thaw stability is often used as measure of long term stability. On the other hand high freeze/thaw stability is often required as a material property. To this end the potential of multisample analytical centrifugation was evaluated as an accelerated test procedure.
A new multisample approach is presented using analytical centrifugation (STEP-Technology), which allows for an accelerated characterization of destabilization processes (creaming, sedimentation, coalescence, phase separation). The kinetics of these destabilizing processes can be traced simultaneously for up-to 12 different samples with temperature control in the range between 4 and 60 °C.
Analytical centrifugation measures in a rapid way the inherent stability of the samples. Therefore, alterations due to accelerated aging by freeze/thaw cycling can be traced far more earlier than by naked eye.
The wide application potential of this approach is demonstrated by examples of measurements on paints, cosmetics and food products.
Thickener performance traced by multisample analytical centrifugation
T. Sobisch, D. Lerche, L.U.M. GmbH, www.lum-gmbh.com
Rudower Chaussee 29, 12489 Berlin, Germany
Polymeric thickeners are important ingredients to adjust flow properties and stability of formulations. The effect of polymeric additives on dispersion properties is rather complex (viscosity of the continuous phase, adsorption and depletion effects, interaction with other ingredients). Therefore optimum formulation requires extensive experimental investigations.
A new multisample approach is presented using analytical centrifugation (STEP-Technology), which allows for an accelerated characterization of separation stability. Even more, comparing measurements at different centrifugal acceleration information on flow properties is also available (Newtonian, shear thinning or thickening behaviour, yield point, compressive yield stress). The kinetics of separation can be traced simultaneously for up-to 12 different samples with temperature control in the range between 4 and 60 °C.
The potential of multisample analytical centrifugation for formulation design was demonstrated investigating the effect of particle (calcium carbonate, silica) and polymer (polyacryl amide) concentration on dispersion properties of different stabilized suspensions.
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