Ussing chambers

Absorption of angiotensin II antagonists in Ussing chambers, Caco-2, perfused jejunum loop and in vivo importance of drug ionization in the in vitro prediction of in vivo absorption. Eur. J. Pharm. Sci. 2000, 10, 215-224. 

H Lennernas, S Nylander, AL Ungell. Jejunal permeability A comparison between the Ussing chamber technique and the single-pass perfusion in humans. Pharm Res 14 667-671, 1997. 

Investigations of regional differences in permeability and metabolism have been carried out using a variety of animal models [22, 29, 75, 102, 109, 112, 137]. Animal tissues (mainly from rats) are widely used in the Ussing chamber to investigate intestinal transport of drugs, and regional aspects [29, 75, 138], whereas few studies have been conducted with human tissues due to their limited availability. 

As shown in Figure 4.2, the modified Ussing chamber system consists of two half chambers which when clamped together are separated by a piece of... 

Figure 4.2 The modified Ussing chamber consisting of a donor and a receptor chamber which when clamped together are separated by a piece of tissue (intestinal, nasal, buccal, etc). The available area for diffusion (highlighted in a green circle to enhance visibility) is 0.64 cm2 and the volume of solution applied to each chamber is 1.5 ml. The applied solution is bubbled with carbogen gas (95% O2 + 5% CO2) that enters the chambers through the gas ports (See also Color Insert.)...

The ex vivo techniques of drug permeability using the Ussing chamber has extensively developed in the last few decades. It is very easy to monitor and therefore to maintain tissue viability throughout the study. This is ensured by monitoring the transepithelial potential difference and short-circuits current... 

Even though the Ussing chamber method is used mostly to study drug permeability in liquid-liquid interphase, it has been demonstrated by Osth et al. 

Cremaschi et al. [39] investigated transepithelial pathways of eel calcitonin, corticotrophin, sucrose, and polyethylene glycol-4000 (PEG-4000) transport across the nasal epithelium using rabbit nasal mucosa mounted on Ussing chamber that was maintained at 27°C. The electrical parameters of the tissues were those of leaky epithelium that allow macromolecules to permeate paracellularly their observation was similar to the finding made by McMartin et al. [40] in which the authors described the nasal epithelium as leaky with... 

Figure 5.2 Literature data on fraction of drugs absorbed (in percent) after human nasal administration versus apparent permeability (Tapp) data from Ussing chamber studies on porcine nasal mucosa (Reprinted with permission from Elsevier B.V.).

Osth K, Paulsson M, Bjork E, Edsman K (2002) Evaluation of drug release from gels on pig nasal mucosa in a horizontal Ussing chamber. J Control Rel 83 377-388. 

Osth K, Grasjo J, Bjork E (2002) A new method for drug transport studies on pig nasal mucosa using a horizontal Ussing chamber. J Pharm Sci 91 1259-1273. 

Hosoya K, Kubo H, Natsume H, Sugibayashi K, Morimoto Y (1994) Evaluation of enhancers to increase nasal absorption using Ussing chamber technique. Biol Pharm Bull 17 316-322. 

Ussing chambers Good screening model Tissue viability... 

In an attempt to increase the biorelevance of the Ussing chambers technique even further, the use of simulated intestinal fluids (FaSSIF and FeSSIF) as transport media was recently evaluated [105], However, the potential difference collapsed to zero after 120 min when exposed to FaSSIF solution and permeability for mannitol was increased twofold. Electron micrographs revealed erosion of the villi tips and substantial denudation of the microvilli after exposure of the ileal tissue to FaSSIF and FeSSIF [105],... 

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