Publications by authors named "R Bogner"
Cryopreservation is important in manufacturing of cell therapy products, influencing their safety and effectiveness. During freezing and thawing, intracellular events such as dehydration and ice formation can impact cell viability. In this study, the impact of controlling the ice nucleation temperature on intracellular events and viability were investigated.
View Article and Find Full Text PDFPurpose: The pharmaceutical literature contains examples wherein desupersaturation from high concentrations does not proceed to equilibrium concentration of the thermodynamically most stable form but remains above equilibrium. The purpose of the current research was to investigate the effect of structurally related compounds on desupersaturation kinetics as a possible explanation for a higher than equilibrium solubility after crystal growth of γ-indomethacin (γ-IMC).
Methods: Three structurally related compounds (SRC) - cis-sulindac (c-SUL), trans-sulindac (t-SUL) and indomethacin-related compound-A (IMC-A) -were investigated.
Article Synopsis
- The lyophilization process can affect the stability of nanoparticles due to higher concentrations in the freeze-concentrate, making controlled ice nucleation an important technique in the pharmaceutical industry for uniform ice formation.
- Research focused on the stability of solid lipid nanoparticles, polymeric nanoparticles, and liposomes under varying freezing conditions, finding that the residual moisture and particle size were largely unaffected by the method of ice nucleation.
- Using trehalose as a lyoprotectant improved the long-term stability of freeze-dried liposomes compared to sucrose, showing it to be a more effective option for maintaining stability at higher temperatures.
Although bulk biotherapeutics are often frozen during fill finish and shipping to improve their stability, they can undergo degradation leading to losses in biological activity during sub-optimal freeze-thaw (F/T) process. Except for a few small-scale studies, the relative contribution of various F/T stresses to the instability of proteins has not been addressed. Thus, the objective of this study was to determine the individual contributions of freeze-concentration, ice surface area, and processing time to protein destabilization at a practical manufacturing-scale.
View Article and Find Full Text PDFRaman scattering shows promise as a powerful routine tool, to determine both secondary and the smaller tertiary structural changes that precede aggregation in both solutions and solids. A method was developed utilizing principal component analysis (PCA) of Raman spectra for detection of small, but meaningful, pH induced changes in tertiary protein structure linked to aggregate formation using α-lactalbumin solutions as a model. The sample preparation and spectral parameters, were optimized for a bulk Raman probe.
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