In Vitro Performance Testing of the Novel Medspray® Wet Aerosol Inhaler Based on the Principle of Rayleigh Break-up

Purpose: A new inhaler (Medspray(R)) for pulmonary drug delivery based on the principle of Rayleigh break-up has been tested with three different spray nozzles (1.5; 2.0 and 2.5 mu m) using aqueous 0.1% (w/w) salbutamol and 0.9% (w/w) sodium chloride solutions. Materials and methods: Particle size distributions in the aerosol were measured with the principles of time of flight (APS) and laser diffraction (LDA). Results: The Medspray(R) inhaler exhibits a highly constant droplet size distribution in the aerosol during dose emission. Droplets on the basis of Rayleigh break-up theory are monodisperse, but due to some coalescence the aerosols from the Medspray(R) inhaler are slightly polydisperse. Mass median aerodynamic diameters at 60 l.min(-1) from APS are 1.42; 1.32 and 1.27 times the theoretical droplet diameters (TD's) and median laser diffraction diameters are 1.29; 1.14 and 1.05 times TD for 1.5; 2.0 and 2.5 mu m nozzles (TD: 2.84; 3.78 and 4.73 mu m respectively). Conclusions: The narrow particle size distribution in the aerosol from the Medspray(R) is highly reproducible for the range of flow rates from 30 to 60 l.min(-1). The mass median aerodynamic droplet diameter can be well controlled within the size range from 4 to 6 mu m at 60 l.min(-1)

Advances in experimental and mechanistic computational models to understand pulmonary exposure to inhaled drugs

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Data Envelopment Analysis (DEA) with integer and negative inputs and outputs

Selecting an appropriate model in DEA to calculate the efficiency of DMUs has always been considered by science researchers. Original models of DEA have been implemented only for some technologies which have positive inputs and outputs feature. In this paper, first we examine semi-oriented radial measure (SORM) model to calculate the efficiency of units based on negative data. After providing a review of the disadvantages to the mentioned model, we present its modified model. Then a new model is offered to evaluate the main units in the presence of negative integer data. Finally, a numerical example is provided in which the efficiency of the units is calculated by using the mentioned models

A consensus research agenda for optimising nasal drug delivery

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