Rhodamine-123: a p-glycoprotein marker complex with sodium lauryl sulfate

ABSTRACT

Aim of this study was to investigate the role of sodium lauryl sulfate [SLS] as P- glycoprotein inhibitor. The everted rat gut sac model was used to study in-vitro mucosal to serosal transport of Rhodamine-123 [Rho-123]. Surprisingly, SLS decreases the serosal absorption of Rho-123 at all investigated concentrations. Investigation reveals complex formation between Rhodamine-123 and sodium lauryl sulfate. Interaction profile of SLS and Rho-123 was studied at variable SLS concentrations. The SLS concentration higher than critical micelle concentration [CMC] increases the solubility of Rho-123 but could not help in serosal absorption, on the contrary the absorption of Rho-123 decreased. Rho-123 and SLS form pink color complex at sub-CMC. The SLS concentrations below CMC decrease the solubility of Rho-123. For further studies, Rho-123 and SLS complex was prepared by using solvent evaporation technique and characterized by using differential scanning calorimeter [DSC]. Thermal analysis also proved the formation of complex between SLS and Rho-123. The P values were found to be significant [<0.05] except group comprising 0.0001% SLS, and that is because 0.0001% SLS is seems to be very low to affect the solubility or complexation of Rho-123