The effect of ethanol on the habit and in vitro aerodynamic results of dry powder inhalation formulations containing ciprofloxacin hydrochloride

In the case of dry powder inhalation systems(DPIs),the development of carrierfree formulations has gained increased attention.Thereby,spray-drying is a promising technology and is widely used to produce carrier-free DPIs.Numerous works have been published about the co-spray-drying of active ingredients with various solid excipients and their effect on the physicochemical characteristics and aerodynamic properties of the formulations.However,only a few studies have been reported about the role of the solvents used in the stock solutions of spray-dried formulations.In the present work,DPI microcomposites containing ciprofloxacin hydrochloride were prepared by spray-drying in the presence of different ethanol concentrations.The work expresses the roughness,depth and width of the dimples for particle size as a novel calculation possibility,and as a correlation between the MMAD/D_(0.5)ratio and correlating it with cohesion work,these new terms and correlations have not been published–to the best of our knowledge–which has resulted in gap-filling findings.As a result,different proportions of solvent mixtures could be interpreted and placed in a new perspective,in which the influence of different concentrations of ethanol on the habit of the DPI formulations,and thus on in vitro aerodynamic results.Based on these,it became clear why we obtained the best in vitro aerodynamic results for DPI formulation containing 30%ethanol in the stock solution.

GPU-enhanced DEM analysis of flow behaviour of irregularly shaped particles in a full-scale twin screw granulator

During twin screw granulation(TSG),small particles,which generally have irregular shapes,agglomerate together to form larger granules with improved properties.However,how particle shape impacts the conveying characteristics during TSG is not explored nor well understood.In this study,a graphic processor units(GPUs)enhanced discrete element method(DEM)is adopted to examine the effect of particle shape on the conveying characteristics in a full scale twin screw granulator for the first time.It is found that TSG with spherical particles has the smallest particle retention number,mean residence time,and power consumption;while for TSG with hexagonal prism(Hexp)shaped particles the largest particle retention number is obtained,and TSG with cubic particles requires the highest power consumption.Furthermore,spherical particles exhibit a flow pattern closer to an ideal plug flow,while cubic particles present a flow pattern approaching a perfect mixing.It is demonstrated that the GPU-enhanced DEM is capable of simulating the complex TSG process in a full-scale twin screw granulator with non-spherical particles.

Comparison of near-infrared spectroscopy and DEM simulations for tracing spatial dispersion of water during mixing

The aim of this work was to validate a wet mixing process, in which a liquid spray is used to impregnate particles during mixing. The experimental results obtained using a bladed-mixer with a near-infrared sensor were compared with the results obtained using a 1 ： 1 discrete element method simulation. The porous particles used in both cases absorbed the sprayed liquid for a process time of about 18 min. Mul- tiple sensors attached to the mixer wall continuously monitored the liquid contents of passing particles. The sensors were modeled in the simulation and the resulting signals were analyzed and compared with the experimental results. We show that the algorithms used for spray and liquid absorption can be used to predict the moisture distribution inside granular materials in chemical and pharmaceutical processes. Such simulations can help to save money, e.g., in resource-intensive experimental plans and equipment design studies, and by varying material parameters.