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Evaporation rates play a key role in evaporation crystallization and the drying of crystal products. Raman analysis was used to study the effect of the evaporation rate on the polymorphs of indomethacin at room temperature. The studied solvents were highly volatile ethanol, acetone, and ethyl acetate. The approach was based on a mass transfer model of evaporation, and experimental flux measurements were used for model evaluation. Evaporation rates from porous carriers were also investigated. The studied mesoporous silicon microparticles can be used in oral dosage forms of poorly soluble active pharmaceutical ingredients. Evaporation rates of dimethyl sulfoxide from a pure solvent, from indomethacin solutions, and from solutions containing microparticles were measured at 100 °C. An evaporation rate model of porous particles was used and the predicted results were compared with the experimental results obtained. [ABSTRACT FROM AUTHOR]

Abstract: Nanosized titania (TiO2) powder has been generated using a turbulent H2–O2 flame with a spray of liquid Ti-precursor (TEOT). The collection was performed on a polished stainless steel surface inside the flame or outside the flame very close to the flame tip. According to the XRD-analysis, a large fraction of the titania was found to consist of anatase when collected further away from the flame but, when collected inside the luminous part of the flame, the material layer was seen to be gradually transforming into rutile. Also sintering of the sub 10 nm particles into larger particles on the collection plate was observed, mostly within the flame where the temperature zone was 1100–1500 °C. When utilising the process, formation of rutile can be avoided by performing the collection sufficiently far away from the flame tip. As a result of the study, an estimate of particle size on the collection substrate, crystal size and anatase/rutile fraction on different material production rates and as a function of collection distance can be given. Also an estimate for the rate of transformation from anatase into rutile can be given. [Copyright &y& Elsevier]