On the suitability of k–ε turbulence modeling for aerosol deposition in the mouth and throat: a comparison with experiment

Introduction: Early dry powder inhalers (DPIs) were designed for low drug doses in asthma and COPD therapy. Nearly all concepts contained carrier-based formulations and lacked efficient dispersion principles. Therefore, particle engineering and powder processing are increasingly applied to achieve acceptable lung deposition with these poorly designed inhalers. Areas covered: The consequences of the choices made for early DPI development with respect of efficacy, production costs and safety and the tremendous amount of energy put into understanding and controlling the dispersion performance of adhesive mixtures are discussed. Also newly developed particle manufacturing and powder formulation processes are presented as well as the challenges, objectives, and new tools available for future DPI design. Expert opinion: Improved inhaler design is desired to make DPIs for future applications cost-effective and safe. With an increasing interest in high dose drug delivery, vaccination and systemic delivery via the lungs, innovative formulation technologies alone may not be sufficient. Safety is served by increasing patient adherence to the therapy, minimizing the use of unnecessary excipients and designing simple and self-intuitive inhalers, which give good feedback to the patient about the inhalation maneuver. For some applications, like vaccination and delivery of hygroscopic formulations, disposable inhalers may be preferred. ARTICLE HISTORY

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“…For the experimental assessment of drug deposition in the human throat, different anatomical models are used [125][126][127] …”

Section: Dpi Design and Pulmonary Drug Deposition And Distributionmentioning

confidence: 99%

Dry powder inhalation: past, present and future

Boer

Hagedoorn

Hoppentocht

et al. 2016

Expert Opinion on Drug Delivery

222

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“…An idealized mouth model based on the idealized mouththroat geometry developed at ARLA (Aerosol Research Laboratory of Alberta) (see Stapleton et al 2000;DeHaan and Finlay 2001;Grgic et al 2003) is adopted here (see Figure 1). This geometry is an average geometrical model for adults based on information available in the literature, supplemented with separate measurements using computed tomography (CT) scans of patients (n = 10) with no visible airway abnormalities and by the observation of living subjects (n = 5).…”

Section: Idealized Mouth Geometrymentioning

confidence: 99%

“…CFD has been used to investigate particle deposition in the extrathoracic region for large diameter inlets-e.g., DeHaan (2002), Matida et al (2003), Stapleton et al (2000) in the oropharynx, Sarangapani and Wexler (2000) using the nasal tract, Yu et al (1998) for particle diffusion in human upper respiratory system, and Li et al (1996) for deaggreagation of particles. In the present work, particle deposition in the mouth for different small diameter inlets is simulated using the RANS equations along with the EIM proposed by Gosman and Ioannides (1981) having near-wall corrections based on Matida et al (2003).…”

Section: Introductionmentioning

confidence: 99%

Simulation of Particle Deposition in an Idealized Mouth with Different Small Diameter Inlets

Matida

DeHaan

Finlay

et al. 2003

Aerosol Science and Technology

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“…Given the costs and ethical concerns associated with clinical trials, alternative approaches for predicting deposition, including in vitro and in silico methodologies, provide useful benchmarks for the evaluation of inhaled aerosol products in the early stages of their development. In vitro models of the human upper airways-both realistic and idealized-have proven useful in estimating extrathoracic deposition and total lung doses of pharmaceutical aerosols (Stapleton et al 2000;Olsson et al 2010;Delvadia et al 2012). At the same time, in silico methods can provide insight into deposition mechanisms that are difficult to examine experimentally (Finlay and Martin 2008).…”

Section: Introductionmentioning

confidence: 99%