SummaryHoneybees in controlled-environment rooms developed flight activity patterns in response to the cycles of light and dark. As the photophase was lengthened, flight activity per unit time decreased, and in continuous light the diurnal rhythm faded. By altering the timing of the photophase, bees could be conditioned to high flight activity at times other than their "normal" peak flight period in the afternoon.
The reaction of amino acid derived N-carboxyanhydrides (NCAs) with unprotected amino acids under carefully controlled aqueous continuous flow conditions realized the formation of range of di-and tripeptide products in 60-85% conversion at productivities of up to 535 g.L-1 h-1. This required a fundamental understanding of the physicochemical aspects of the reaction resulting in the design of a bespoke continuous stirred tank reactor (CSTR) with continuous solids addition, high shear mixing, automated pH control to avoid the use of buffer, and efficient heat removal to control the reaction at 1±1 °C.
To support the practical implementation of the International Council for Harmonisation (ICH) Q3D guideline, which describes a risk-based approach to the control of elemental impurities in drug products, a consortium of pharmaceutical companies has established a database to collate the results of analytical studies of the levels of elemental impurities within pharmaceutical excipients. This database currently includes the results of 26,723 elemental determinations for 201 excipients and represents the largest known, and still rapidly expanding, collection of data of this type. Analysis of the database indicates good coverage of excipients relevant to real-world drug product formulations and tested element profiles consistent with ICH Q3D recommendations. The database includes the results from multiple analytical studies for an excipient and thus incorporates within it an indication of both excipient supplier and batch-to-batch variability as well as any variability associated with the different testing organizations and methods employed. The data confirm the findings of earlier smaller studies that elemental impurity concentrations in excipients are generally low and when used in typical proportions in formulated drug products are unlikely to pose a significant patient safety risk. The database is now in active use as one line of evidence in ICH Q3D risk assessments.
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