Effect of Tween-80 on the permeability of rhodamine 123, a P-gp substrate across rat intestinal membranes in vitro / 南方医科大学学报

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the effect of Tween-80 in modulating rhodamine123 (R123) permeability across the intestinal membranes.</p><p><b>METHODS</b>The permeability of R123 or fluorescein sodium (CF) across isolated rat intestinal membranes at the concentration of 5 microg/ml was evaluated using an in vitro diffusion chamber system, in the presence or absence of Tween-80 at different low concentrations. The concentration of R123 or CF in the receptor chamber was determined using fluorospectrophotometry.</p><p><b>RESULTS</b>The intestinal membrane permeability of R123 gradually decreased from the jejunum to the ileum and then to the colon. The serosal-to-mucosal transport of R123 was much greater than its mucosal-to-serosal transport. In the presence of low concentrations of Tween-80, the absorptive transport of R123 was significantly increased while its secretory transport decreased depending on the concentration of Tween-80. However, Tween-80 at the experimental concentrations was found to obviously affect the CF transport across the intestinal membranes.</p><p><b>CONCLUSION</b>Low concentrations of Tween-80 may promote the absorption of P-gp-mediated drugs and therefore improve the oral bioavailability of these drugs.</p>