Synthesis, Characterization, and Micellization Behavior of Cationic Surfactants: n-Alkyl-3-Methylpyridinium Bromides and Their Drug Interaction Study by UV-Visible Spectroscopy and Conductometry

The synthesis of new cationic surfactants i.e., n-hexyl-3-methylpyridium bromide (a) and n-octyl-3-methylpyridium bromide (b), and their characterization using multinuclear nuclear magnetic resonance spectroscopy (NMR) (H-1, C-13) and Fourier-transform infrared spectroscopy (FT-IR) spectroscopic techniques were reported. The micellization behavior of the synthesized surfactants was studied using conductometry and ultraviolet-Visible spectroscopy. The critical micelle concentration (CMC) of compounds a and b was found to be 0.41 and 0.35 m mol L-1, respectively. The effect of temperature on the CMC of these compounds was examined in the range of 298-318 K and thermodynamic parameters (Delta G, Delta H, and Delta S) of the micellization process were calculated. The antibacterial study of the synthesized surfactants revealed their strong activity against different bacterial strains. Moreover, the interaction of drugs i.e., flurbiprofen and ketoprofen, with the synthesized surfactants was investigated for gaining insights into the role of micelles as drug-delivery devices. Drug-surfactant interactions were also confirmed via a conductometric method.