Droplet velocity is an important parameter which can significantly influence inhalation drug delivery performance. Together with the droplet size, this parameter determines the efficiency of the deposition of MDI products at different sites within the lungs. In this study, phase Doppler anemometry (PDA) was used to investigate the instantaneous droplet velocity emitted from MDIs as well as the corresponding droplet size distribution. The nine commercial MDI products surveyed showed significantly different droplet velocities, indicating that droplet velocity could be used as a discriminating parameter for in vitro testing of MDI products. The droplet velocity for all tested MDI products decreased when the testing distance was increased from 3 cm to 6 cm from the front of mouthpiece, with CFC formulations showing a larger decrease than HFA formulations. The mean droplet diameters of the nine MDIs were also significantly different from one-another. Droplet size measurements made using PDA (a number-based technique) could not be directly compared to results obtained using laser light scattering measurements (a volume-based technique). This work demonstrates that PDA can provide unique information useful for characterizing MDI aerosol plumes and evaluating MDI drug delivery efficiency. PDA could also aid the evaluation of in vitro equivalence in support of formulation or manufacturing changes and in evaluation of abbreviated new drug applications (ANDAs) for MDIs.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.ijpharm.2011.12.006 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Locomoting non-magnetic marbles through meniscus emerged on the water surface using a magnetically actuated ferrofluid marble under pulsating and steady magnetic fields.
Soft Matter
January 2025
Center of Excellence in Energy Conversion (CEEC), Department of Mechanical Engineering, Sharif University of Technology, Tehran, Iran.
Recent progress in digital microfluidics has revealed the distinct advantages of liquid marbles, such as minimal surface friction, reduced evaporation rates, and non-wettability compared to uncoated droplets. This study provides a comprehensive examination of an innovative technique for the precise, contamination-free manipulation of non-magnetic water liquid marbles (WLMs) carried by a ferrofluid liquid marble (FLM) under the control of direct current (DC) and pulse-width modulation (PWM) magnetic fields. The concept relies on the phenomenon in which an FLM and WLMs form a shared meniscus when placed together on a water surface, causing the WLMs to closely track the magnetically actuated FLM.
View Article and Find Full Text PDFSuperfast nanodroplet propulsion in 2D nanochannels tuned by strain gradients.
Nanoscale
January 2025
Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing, 211189, China.
Directional transport of droplets is crucial for industrial applications and chemical engineering processes, with significant potential demonstrated in water harvesting, microfluidics, and heat transfer. In this work, we present a novel approach to induce self-driving behavior in nanodroplets within a two-dimensional (2D) nanochannel using a strain gradient, as demonstrated through molecular dynamics simulations. Our findings reveal that a small strain gradient imposed along a nanochannel constructed by parallel surfaces can induce water transport at ultrafast velocities (O(10 m s)), far exceeding macroscale predictions.
View Article and Find Full Text PDFMolecular-Scale Simulation of Wetting of Actin Filaments by Protein Droplets.
J Phys Chem B
January 2025
Department of Computer and Information Sciences, Department of Materials Science and Engineering, University of Delaware, Newark, Delaware 19716, United States.
Liquid phase-separating proteins can form condensates that play an important role in spatial and temporal organization of biological cells. The understanding of the mechanisms that lead to the formation of protein condensates and their interactions with other biomolecules may lead to processing routes for soft materials with tailored geometry and function. Fused in sarcoma (FUS) is an example of a nuclear protein that forms stable complexes, and recent studies have highlighted its ability to wet actin filaments and bundle them into networks.
View Article and Find Full Text PDFPneumatic conveying inkjet bioprinting for the processing of living cells.
Biofabrication
January 2025
Research Group Anatomy, School for Medicine and Health Science, Carl von Ossietzky Universität Oldenburg, Carl von Ossietzky Str.9-11, Oldenburg, 26129, GERMANY.
Inkjet printing techniques are often used for bioprinting purposes because of their excellent printing characteristics, such as high cell viability and low apoptotic rate, contactless modus operandi, commercial availability, and low cost. However, they face some disadvantages, such as the use of bioinks of low viscosity, cell damage due to shear stress caused by drop ejection and jetting velocity, as well as a narrow range of available bioinks that still challenge the inkjet printing technology. New technological solutions are required to overcome these obstacles.
View Article and Find Full Text PDFRecirculatory Solvotaxis of a Nematic Droplet on Water Surface Enabling Miniaturization.
Langmuir
January 2025
Department of Chemical Engineering, Indian Institute of Technology, Guwahati 781039, Assam, India.
Self-organized contact line instabilities (CLI) of a macroscopic liquid crystal (LC) droplet can be an ingenious pathway to generate a large collection of miniaturized LC drops. For example, when a larger drop of volatile solvent (e.g.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!