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Iontophoresis: Applications in Drug Delivery and Noninvasive Monitoring *
Published in Richard H. Guy, Jonathan Hadgraft, Transdermal Drug Delivery, 2002
M. Begoña Delgado-Charro, Richard H. Guy
When an electric potential gradient is established across a membrane, ions on either side will migrate in the direction dictated by their charge. The speed of migration of an ion is determined by its physicochemical characteristics and the properties of the media through which the ion is moving (9,12). The sum of the individual ion fluxes must equal the current supplied by the power source; in other words, there is a “competition” among all the ions present to carry the charge. Obviously, the chances of being a major carrier, and in consequence being efficiently transported through the skin, increase with the electrical mobility and concentration of the ion concerned.
Iontophoresis for the cutaneous delivery of nanoentraped drugs
Published in Expert Opinion on Drug Delivery, 2023
Jayanaraian F. M. Andrade, Marcilio Cunha-Filho, Guilherme M. Gelfuso, Tais Gratieri
These characteristics make passive permeation time-consuming and ineffective in numerous cases, so it is clear that enhancing transcutaneous delivery kinetics is imperative for improving transdermal drug delivery [6]. Hence, to solve the low permeability hindrance of the skin, different strategies have been explored, and iontophoresis appears as one of the most promising. Iontophoresis is a noninvasive physical method that employs a moderate electric current (<0.5 mA/cm2) to enhance a substance’s penetration toward a biological tissue [7]. The electrical field causes a reversible alteration in membrane barrier properties, forming transient pores in the lipid bilayer. Moreover, such external physical force elicits the electrical mobility of charged compounds toward the tissue and generates a solvent flow. All these effects combined can increase transcutaneous drug permeation, even for neutral molecules [8].
Effect of particle morphology on performance of an electrostatic air–liquid interface cell exposure system for nanotoxicology studies
Published in Nanotoxicology, 2021
Ta-Chih Hsiao, Hsiao-Chi Chuang, Jing-Chi Lin, Tsun-Jen Cheng, Li-Ti Chou
The morphology effect of NPs was investigated using particles with different morphologies. As shown in Figure 5, the experimental results were transformed using drift velocity under an identical flow rate (Q=1.5 lpm) and electrode distance (h=20mm). The collection efficiency curves of different particle morphologies did not merge well. The performance for identical electrical mobility particle size (dp,m = 61.5nm) with six morphologies was further analyzed. However, the collection efficiency of particles with an identical electrical mobility particle size (dp,m = 61.5nm) but with different morphologies under flow rates of 1.5 and 0.3 lpm was very similar. Therefore, for NPs, the effect of particle morphology on the ESP-ALI performance is insignificant, and the scattering data after rescaling may have been due to turbulent mixing.
Acute neuroradiological, behavioral, and physiological effects of nose-only exposure to vaporized cannabis in C57BL/6 mice
Published in Inhalation Toxicology, 2020
Yasmeen M. Farra, Matthew J. Eden, James R. Coleman, Praveen Kulkarni, Craig F. Ferris, Jessica M. Oakes, Chiara Bellini
To characterize our animal model, we first described the number concentration and size distribution of particles in the aerosols of vaporized cannabis, measuring an average count median diameter of 243 nm (Figure 3). Hiller et al. first reported an electrical mobility-based count median aerodynamic diameter for cannabis smoke that varied between 350 and 410 nm, as the THC content of the cigarette increased from 0.89% to 2.87% (Hiller et al. 1984). Anderson et al. from the same group later corrected these values to be within the 96 to 110 nm range (Anderson et al. 1989). Our particle size measurements for vaporized cannabis, which are also based on electrical mobility, fall in the center of the range identified by these two reports on cannabis smoke. In addition, our particle dimensions closely resemble those of particles generated from the combustion of cigarettes (Adam et al. 2009; McGrath et al. 2009; Kane et al. 2010), other plant-based materials (Chakrabarty et al. 2006; Hosseini et al. 2010), and electronic cigarettes (Ingebrethsen et al. 2012; Zhao et al. 2016). As expected, our vaporizer yielded smaller particles compared to nebulizers (Martin and Finlay 2015), which were reported to generate particulate matter with mass median diameter MMD = 2 µm and GSD = 2.2 (Lichtman et al. 2000).