Salbutamol sulfate absorption across Calu-3 bronchial epithelia cell monolayer is inhibited in the presence of common anionic NSAIDs.

PURPOSE

The aim of this study was to characterize the permeability kinetics of salbutamol sulfate, a commonly used β2-agonist in the treatment of asthma exacerbation, across Calu-3 respiratory epithelial cell monolayers in the presence of non-steroidal anti-inflammatory drugs (NSAIDs), as they have been implicated to be able to modulate organic cation transporters (OCTs).

METHODS

Calu-3 cell monolayers were grown in a liquid covered culture (LCC) configuration on 0.33 cm(2) Transwell polyester cell culture supports. Monolayers, cultured between 11 and 14 days were evaluated for epithelial resistance, tight junction integrity, and expression of OCT using Western blot analysis. The transport of salbutamol across the monolayer was studied as a function of concentration. Directional transport was investigated by assessing apical-basal (a-b) and basal-apical (b-a) directions. The influence of a non-specific OCT inhibitor (tetraethylammonium, TEA) and three NSAIDs (aspirin, ibuprofen, and indomethacin) on the uptake of salbutamol was studied.

RESULTS

The flux of salbutamol sulfate increased with increasing concentration before reaching a plateau, suggesting the involvement of a transport-mediated uptake mechanism. Western blot analysis detected the presence of OCT1-3 and N1 and N2 sub-types, suggesting the presence of functioning transporters. The apparent permeability (P(app)) of 0.1 mM salbutamol across the epithelial monolayer displayed directional transport in the a-b direction which was inhibited by ˜70% in the presence of TEA, suggesting OCT-mediated uptake. Likewise, the uptake of 0.1 mM salbutamol was decreased in the presence of all the three NSAIDs, supporting a mechanism whereby NSAIDs inhibit absorption of salbutamol across the bronchial epithelium via effects on the OCT transporters.

CONCLUSION

This study demonstrates that NSAIDs influence the uptake kinetics of salbutamol in an in vitro Calu-3 cell system.