Armed Rollers: Does Nestling’s Vomit Function as a Defence against Predators?

Chemical defences against predators are widespread in the animal kingdom although have been seldom reported in birds. Here, we investigate the possibility that the orange liquid that nestlings of an insectivorous bird, the Eurasian roller (Coracias garrulus), expel when scared at their nests acts as a chemical defence against predators. We studied the diet of nestling rollers and vomit origin, its chemical composition and deterrent effect on a mammal generalist predator. We also hypothesized that nestling rollers, as their main prey (i.e. grasshoppers) do from plants, could sequester chemicals from their prey for their use. Grasshoppers, that also regurgitate when facing to a threat, store the harmful substances used by plants to defend themselves against herbivores. We found that nestling rollers only vomit after being grasped and moved. The production of vomit depended on food consumption and the vomit contained two deterrent chemicals (hydroxycinnamic and hydroxybenzoic acids) stored by grasshoppers and used by plants to diminish herbivory, suggesting that they originate from the rollers’ prey. Finally, we showed for the first time that the oral secretion of a vertebrate had a deterrent effect on a model predator because vomit of nestling rollers made meat distasteful to dogs. These results support the idea that the vomit of nestling rollers is a chemical defence against predators.Financial support was provided by the Junta de Andalucía (project P06-RNM-02177) and the Spanish Ministry of Science and Education/FEDER (projects CGL2008-00718 and CGL2011-27561)

Excipient selection can significantly affect solid-state phase transformation in formulation during wet granulation

Phase transformations in formulations can lead to instability in physicochemical, biopharmaceutical, and processing properties of products. The influences of formulation design on the optimal dosage forms should be specified. The aim here was to investigate whether excipients with different water sorption behavior affect hydrate formation of nitrofurantoin in wet masses. Nitrofurantoin anhydrate was used as a hydrate-forming model drug, and 4 excipients with different water-absorbing potential (amorphous low-substituted hydroxypropylcellulose, modified maize starch, partially amorphous silicified microcrystalline cellulose, and crystalline α-lactose monohydrate) were granulated with varying amounts of purified water. Off-line evaluation of wet masses containing nitrofurantoin anhydrate and excipient (1∶1) was performed using an X-ray powder diffractometer (XRPD) and near-infrared spectroscopy, and drying phase was evaluated by variable temperature XRPD. Only amorphous excipient in the formulation retarded hydrate formation of an active pharmaceutical ingredient (API) at high water contents. Hygroscopic partially crystalline excipient hindered hydrate formation of API at low water contents. Crystalline excipient was unable to control hydrate formation of API. The character of excipient affects the stability of formulation. Thus, correct selection of excipients for the formulation can control processing-induced phase transitions and improve the storage stability of the final dosage form

Characterization of a cyclosporine solid dispersion for inhalation

For lung transplant patients, a respirable, inulin-based solid dispersion containing cyclosporine A (CsA) has been developed. The solid dispersions were prepared by spray freezedrying. The solid dispersion was characterized by water vapor uptake, specific surface area analysis, and particle size analysis. Furthermore, the mode of inclusion of CsA in the dispersion was investigated with Fourier transform infrared spectroscopy. Finally, the dissolution behavior was determined and the aerosol that was formed by the powder was characterized. The powder had large specific surface areas (∼160 m2). The water vapor uptake was dependent linearly on the drug load. The type of solid dispersion was a combination of a solid solution and solid suspension. At a 10% drug load, 55% of the CsA in the powder was in the form of a solid solution and 45% as solid suspension. At 50% drug load, the powder contained 90% of CsA as solid suspension. The powder showed excellent dispersion characteristics as shown by the high emitted fraction (95%), respirable fraction (75%), and fine-particle fraction (50%). The solid dispersions consisted of relatively large (x50≈7 μm), but low-density particles (ρ≈0.2 g/cm3). The solid dispersions dissolved faster than the physical mixture, and inulin dissolved faster than CsA. The spray freeze-drying with inulin increased the specific surface area and wettability of CsA. In conclusion, the developed powder seems suitable for inhalation in the local treatment of lung transplant patients