Effects of long-chains of zwitterionic micelles on binding constants of triflusal and acetylsalicylic acid

A spectrophotometric study of the reaction of the alkaline hydrolysis of triflusal (TFL) and acetylsalicylic acid (ASA) in the presence of zwitterionic micelles was carried out, with the objective of determining the effects of the hydrophobic and electrostatic interactions on the micellar union of both drugs. A series of zwitterionic surfactants of alkyldimethylammonio propanesulfonate (SB3-n) were used: decyldimethylammonio propanesulfonate (SB3-10), tetradecyldimethylammonio propanesulfonate (SB3-14), hexadecyldimethylammonio propanesulfonate (SB3-16). This reaction is inhibited at higher surfactant concentrations. The experimental data has been processed according to the micellar pseudophase model. The values of the binding constants of both drugs in the micelle (KS) determine the importance of the hydrophobic and electrostatic interactions in the micelle solubilization of both drugs.