The knowledge of possible acute and long-term health effects of aerosols inhaled from electronic cigarettes (ECs) is still limited partially due to incomplete awareness of physical phenomena related to EC-aerosol dynamics. This short review discusses the basic processes of aerosol transformation (dynamics) upon inhalation, indicating also the need for the accurate determination of the size of droplets in the inhaled EC-mist. The significance of differences in the aerosol particle size distribution for the prediction of regional deposition of inhaled mist in the respiratory system is highlighted as a decisive factor in the interactions of inhaled EC-aerosols with the organism.

Direct physicochemical interactions between the major components of electronic cigarette liquids (e-liquids): glycerol (VG) and propylene glycol (PG), and lung surfactant (LS) were studied by determining the dynamic surface tension under a simulated breathing cycle using drop shape method. The studies were performed for a wide range of concentrations based on estimated doses of e-liquid aerosols (up to 2500 × the expected nominal concentrations) and for various VG/PG ratios. The results are discussed as relationships among mean surface tension, surface tension amplitude, and surface rheological properties (dilatational elasticity and viscosity) versus concentration and composition of e-liquid. The results showed that high local concentrations (>200 × higher than the estimated average dose after a single puffing session) may induce measurable changes in biophysical activity of LS; however, only ultra-high e-liquid concentrations inactivated the surfactant. Physiochemical characterization of e-liquids provide additional insights for the safety assessment of electronic nicotine delivery systems (ENDS).

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Understanding the influence of process conditions on the properties of pharmaceutical products is critical to their optimal and cost-effective design and manufacture. The aim of this study was to investigate the effect of changing processing variables on the physical properties of spray-dried mannitol and co-spray-dried mannitol/disodium cromoglycate (DSCG) formulations intended for therapeutic inhalation. A 2 4 full factorial design was performed to assess the consequences of altering the following spray-drying parameters: feed flow rate, nozzle gas flow rate, drying gas inlet temperature, and aspirator capacity (drying gas flow rate). Aqueous solutions of mannitol and mannitol/DSCG were spray-dried using a laboratory-scale spray dryer, and the products were characterized in terms of particle size distribution, powder yield, and particle morphology. These physical properties were found to be affected mainly by two processing variables: nozzle gas flow rate and drying gas inlet temperature. In addition, optimal conditions for the production of inhalable mannitol powders were obtained, generating a yield of 90% by weight of round and smooth particles with a volume median diameter of 4.28 μm. Mannitol/DSCG formulations co-spray-dried in the same conditions had similar characteristics. The results of this study can be applied to controlled formulation of various spray-dried powders for inhalation.

This article presents the concept of a method of improving the dynamics of combustion in boilers operating in power plants, cogeneration plants, and heating plants by introducing a catalyst that is fed with a carrier in the form of droplets. Thanks to the proposed method, a greater degree of fuel burnout can be obtained, which, in turn, results in lower energy consumption in the case of producing the same amount of power. The parameters of the emitted exhaust gases and ash are also improved. The method described in the article involves the adding of a catalyst to the dust pipe of the boiler, which improves the combustion parameters. The catalyst was implemented using a sprayer/nebulizer. In order to obtain the correct flow parameters, the sprayer was modeled using CFD calculations. The calculations include trajectories, velocities and concentrations with regards to various flow parameters. Particular attention should be paid to the model of the evaporation of moving droplets. The results of these calculations enable the parameters that guarantee that the catalyst reaches the dust channel outlet in the desired form to be assessed. The analysis is an introduction to experimental research that is carried out on a medium and large scale.