Producing solid-state formulations of biologics remains a daunting task despite the prevalent use of lyophilization and spray drying technologies in the biopharmaceutical industry. The challenges include protein stability (temperature stresses), high capital costs, particle design/controllability, shortened processing times and manufacturing considerations (scalability, yield improvements, aseptic operation, etc.).
View Article and Find Full Text PDFA new "three-micropipette manipulation technique" for forming, dehydrating, crystallizing, and resolvating nanograms of salt material has been developed to study supersaturated single microdroplets and microcrystals. This is the first report of studies that have measured in situ both supersaturation (as homogeneous nucleation) and saturation (as microcrystal redissolution) for single microdroplets of NaCl solution using the micropipette technique. This work reports a measure of the critical supersaturation concentration for homogeneous nucleation of NaCl (10.
View Article and Find Full Text PDFWhen a solute is present in an aqueous droplet, the water activity in the droplet and the rate of droplet dissolution are both decreased (as compared to a pure water droplet). One of the main parameters that controls this effect is the dynamically changing solute concentration, and therefore water activity and chemical potential, at the droplet interface. This work addresses the importance of understanding how water activity changes during solution droplet dissolution.
View Article and Find Full Text PDFControlled enzyme dehydration using a new processing technique of Microglassification™ has been investigated. Aqueous solution microdroplets of lysozyme, α-chymotrypsin, catalase, and horseradish peroxidase were dehydrated in n-pentanol, n-octanol, n-decanol, triacetin, or butyl lactate, and changes in their structure and function were analyzed upon rehydration. Water solubility and microdroplet dissolution rate in each solvent decreased in the order: butyl lactate > n-pentanol > triacetin > n-octanol > n-decanol.
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