Derivation of first-order dissolution rates to estimate particle clearance and burden in the human respiratory tract

Abstract Inhalation is a portal-of-entry for aerosols via the respiratory tract where particulate burden accumulates depending on sites of particle deposition, normal clearance mechanisms, and particle solubility. The time available for dissolution of particles is determined by the balance between t...

Full description

Bibliographic Details
Main Authors: James S. Brown, Gary L. Diamond
Format: Article
Language:English
Published: BMC 2023-04-01
Series:Particle and Fibre Toxicology
Online Access:https://doi.org/10.1186/s12989-023-00523-z
_version_ 1797836659475087360
author James S. Brown
Gary L. Diamond
author_facet James S. Brown
Gary L. Diamond
author_sort James S. Brown
collection DOAJ
description Abstract Inhalation is a portal-of-entry for aerosols via the respiratory tract where particulate burden accumulates depending on sites of particle deposition, normal clearance mechanisms, and particle solubility. The time available for dissolution of particles is determined by the balance between the rate of particle clearance from a region and their solubility in respiratory solvents. Dissolution is a function of particle surface area divided by particle volume or mass (i.e., dissolution is inversely proportional to the physical diameter of particles). As a conservative approach, investigators commonly assume the complete and instantaneous dissolution of metals from particles depositing in the alveolar region of the respiratory tract. We derived first-order dissolution rate constants to facilitate biokinetic modeling of particle clearance, dissolution, and absorption into the blood. We then modeled pulmonary burden and total dissolution of particles over time as a function of particle size, density, and solubility. We show that assuming poorly soluble particle forms will enter the blood as quickly as highly soluble forms causes an overestimation of concentrations of the compound of interest in blood and other extrapulmonary tissues while also underestimating its pulmonary burden. We conclude that, in addition to modeling dose rates for particle deposition into the lung, physiologically based pharmacokinetic modeling of pulmonary and extrapulmonary tissues concentrations of moderately and poorly soluble materials can be improved by including estimates of lung burden and particle dissolution over time.
first_indexed 2024-04-09T15:13:34Z
format Article
id doaj.art-0dcf2145ef4b4a3598dd4c1099ebe8ec
institution Directory Open Access Journal
issn 1743-8977
language English
last_indexed 2024-04-09T15:13:34Z
publishDate 2023-04-01
publisher BMC
record_format Article
series Particle and Fibre Toxicology
spelling doaj.art-0dcf2145ef4b4a3598dd4c1099ebe8ec2023-04-30T11:02:55ZengBMCParticle and Fibre Toxicology1743-89772023-04-0120111910.1186/s12989-023-00523-zDerivation of first-order dissolution rates to estimate particle clearance and burden in the human respiratory tractJames S. Brown0Gary L. Diamond1U.S. Environmental Protection Agency, Office of Research and DevelopmentSRC, Inc.Abstract Inhalation is a portal-of-entry for aerosols via the respiratory tract where particulate burden accumulates depending on sites of particle deposition, normal clearance mechanisms, and particle solubility. The time available for dissolution of particles is determined by the balance between the rate of particle clearance from a region and their solubility in respiratory solvents. Dissolution is a function of particle surface area divided by particle volume or mass (i.e., dissolution is inversely proportional to the physical diameter of particles). As a conservative approach, investigators commonly assume the complete and instantaneous dissolution of metals from particles depositing in the alveolar region of the respiratory tract. We derived first-order dissolution rate constants to facilitate biokinetic modeling of particle clearance, dissolution, and absorption into the blood. We then modeled pulmonary burden and total dissolution of particles over time as a function of particle size, density, and solubility. We show that assuming poorly soluble particle forms will enter the blood as quickly as highly soluble forms causes an overestimation of concentrations of the compound of interest in blood and other extrapulmonary tissues while also underestimating its pulmonary burden. We conclude that, in addition to modeling dose rates for particle deposition into the lung, physiologically based pharmacokinetic modeling of pulmonary and extrapulmonary tissues concentrations of moderately and poorly soluble materials can be improved by including estimates of lung burden and particle dissolution over time.https://doi.org/10.1186/s12989-023-00523-z
spellingShingle James S. Brown
Gary L. Diamond
Derivation of first-order dissolution rates to estimate particle clearance and burden in the human respiratory tract
Particle and Fibre Toxicology
title Derivation of first-order dissolution rates to estimate particle clearance and burden in the human respiratory tract
title_full Derivation of first-order dissolution rates to estimate particle clearance and burden in the human respiratory tract
title_fullStr Derivation of first-order dissolution rates to estimate particle clearance and burden in the human respiratory tract
title_full_unstemmed Derivation of first-order dissolution rates to estimate particle clearance and burden in the human respiratory tract
title_short Derivation of first-order dissolution rates to estimate particle clearance and burden in the human respiratory tract
title_sort derivation of first order dissolution rates to estimate particle clearance and burden in the human respiratory tract
url https://doi.org/10.1186/s12989-023-00523-z
work_keys_str_mv AT jamessbrown derivationoffirstorderdissolutionratestoestimateparticleclearanceandburdeninthehumanrespiratorytract
AT garyldiamond derivationoffirstorderdissolutionratestoestimateparticleclearanceandburdeninthehumanrespiratorytract