Corneal permeation assay
Assessment of the permeability of new chemical entities (NCE) across rabbit cornea (ex vivo) or across human corneal epithelial cell layers (in vitro) is important in evaluating the NCE ability to enter the eye by transcorneal route.
The permeability experiments across human corneal epithelial cell layers or rabbit corneas are conducted in diffusion chambers to measure the transport of NCE and standard controls. The human corneal epithelial cell layers or rabbit corneas are inserted between two chambers and the cumulative amount of NCE in the receiver chamber versus time is measured.
The rate (apparent permeability coefficient, Papp) of the NCE is compared to the Papp values of the low and high permeability controls. The Papp values of study compounds and standard molecules can be compared to the Papp values of known generic drug molecules across the animal (rabbit, pig) excised cornea from the literature (2-4).
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2. Toropainen E, Ranta VP, Talvitie A, Suhonen P, Urtti A. Culture model of human corneal epithelium for prediction of ocular drug absorption. Invest Ophthalmol Vis Sci 2001,42(12):2942-2948.
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