Comparison of Various Cell Lines and Three-Dimensional Mucociliary Tissue Model Systems to Estimate Drug Permeability Using an In Vitro Transport Study to Predict Nasal Drug Absorption in Rats

Abstract

Recently, various types of cultured cells have been used to research the mechanisms of transport and metabolism of drugs. Although many studies using cultured cell systems have been published, a comparison of different cultured cell systems has never been reported. In this study, Caco-2, Calu-3, Madin-Darby canine kidney (MDCK), EpiAirway and MucilAir were used as popular in vitro cell culture systems, and the permeability of model compounds across these cell systems was evaluated to compare barrier characteristics and to clarify their usefulness as an estimation system for nasal drug absorption in rats. MDCK unexpectedly showed the best correlation (r = 0.949) with the fractional absorption (F_n) in rats. Secondly, a high correlation was observed in Calu-3 (r = 0.898). Also, Caco-2 (r = 0.787) and MucilAir (r = 0.750) showed a relatively good correlation with F_n. The correlation between F_n and permeability to EpiAirway was the poorest (r = 0.550). Because EpiAirway forms leakier tight junctions than other cell culture systems, the paracellular permeability was likely overestimated with this system. On the other hand, because MDCK formed such tight cellular junctions that compounds of paracellular model were less likely permeated, the paracellular permeability could be underestimated. Calu-3, Caco-2 and MucilAir form suitable cellular junctions and barriers, indicating that those cell systems enable the precise estimation of nasal drug absorption.

Keywords: Caco-2; Calu-3; MDCK; apparent permeability coefficient; nasal drug absorption; three-dimensional mucociliary tissue model system.

Figure 1

Comparison of transepithelial electrical resistance (TEER) of each cultured cell systems. The TEER of cultured cell systems was measured by Millicell-ERS (MILLIPORE) before the transport experiment. Bars represent the mean ± S.E. of 3–4 experiments. *: TEER value of EpiAirway was cited from the previous report [22].

Figure 2

Comparison of apparent permeability of paracellular compounds across cultured cell systems. Keys: ACV: acyclovir, ATL: atenolol, SNA: sulfanilic acid, INL: inulin, MAN: mannitol, n.d.: not determined. Bars represent the mean ± S.E. of 3–4 experiments.

Figure 3

Comparison of apparent permeability of transcellular compounds across cultured cell systems. Keys: ANP: antipyrine, QND: quinidine, MTX: methotrexate. Bars represent the mean ± S.E. of 3–4 experiments.

Figure 4

Correlation of the fractional absorption of compounds following nasal application to rats with permeability across EpiAirway (left) and MucilAir (right). Keys; 1: inulin, 2: atenolol, 3: sulfanilic acid, 4: mannitol, 5: acyclovir, 6: quinidine, 7: antipyrine, FA: fractional absorption. The data were fitted to Hill’s sigmoidal equation, with the exception of methotrexate. Fractional absorptions of compounds (except for antipyrine, atenolol and quinidine) were cited from Furubayashi et al. [11]. Data for methotrexate are plotted as an open triangle. Data are expressed as the mean ± S.E. of 3–4 experiments.

Figure 5

Correlation of the fractional absorption of compounds following nasal application to rats with respect to the permeability across Caco-2 (left), Calu-3 (middle) and MDCK (right) monolayer. Keys: 1: inulin, 2: atenolol, 3: sulfanilic acid, 4: mannitol, 5: acyclovir, 6: quinidine, 7: antipyrine, FA: fractional absorption. The data were fitted to Hill’s sigmoidal equation, with the exception of methotrexate. Fractional absorptions of compounds (except for antipyrine, atenolol and quinidine) were cited from Furubayashi et al. [11]. Data for methotrexate are plotted as an open triangle. Data are expressed as the mean ± S.E. of 3–4 experiments.