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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]

A process concept where a solvent removal unit is integrated to a steady-state recycling chromatography process (SSR-SR) offers a possibility to significantly increase the performance of single column chromatographic separation. The advantages of solvent removal for a difficult separation task at conditions typical for industrial scale chromatography were demonstrated by investigating the performance of SSR-SR in separation of glucose and galactose. Two limits for the extent of solvent removal were imposed: maximum total concentration of the solution fed into the column (viscosity limit) and the maximum total concentration achievable in the solvent removal unit (solubility or osmotic pressure limit). The process was optimized using numerical simulation. Three SSR-SR configurations with different positions of the solvent removal unit were compared with (1) the conventional batch process, (2) SSR without solvent removal, and (3) batch process with solvent removal. SSR-SR was found to always improve the productivity. In addition, solvent removal reduced eluent consumption in most cases. The concentration limits and the concentration of the fresh feed were shown to determine which SSR-SR configuration yields the best performance., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Stability of high indomethacin (IMC) content formulations based on ordered mesoporous silica MCM-41 and SBA-15 materials was studied before and after a 3 month storage in stressed conditions (30°C/56% RH). Overall, the physical stability of the samples was found satisfactory after the storage. However, some issues with the chemical stability were noted, especially with the MCM-41 based samples. The stability issues were evident from the decreased HPLC loading degrees of the drug after stressing as well as from the observed extra peaks in the HPLC chromatograms of the drug in the stressed samples. Drug release from the mesoporous formulations before stressing was rapid at pH 1.2 in comparison to bulk crystalline IMC. The release profiles also remained similar after stressing. Even faster and close to complete IMC release was achieved when the pH was raised from 1.2 to 6.8. To our knowledge, this is the first report of chemical stability issues of drugs in mesoporous silica drug formulations. The present results encourage further study of the factors affecting the chemical stability of drugs in mesoporous silica MCM-41 and SBA-15 formulations in order to realize their potential in oral drug delivery., (Copyright © 2011 Elsevier B.V. All rights reserved.)