Comparative studies on the aggregate formation of synthesized zwitterionic gemini and monomeric surfactants in the presence of the amphiphilic antipsychotic drug chlorpromazine hydrochloride in aqueous solution: an experimental and theoretical approach

Abstract

The formation of aggregates, which are widely used in the field of biochemistry and the medical industry, was studied with different compositions of alkyl betaine gemini surfactant (C₁₄Ab) in conjugation with chlorpromazine hydrochloride (CPZ). The results were compared with those of a single-chain zwitterionic surfactant (C₁₂DmCB) of the same type with CPZ. Dynamic light scattering (DLS), confocal laser scanning microscopy (CLSM), and transmission electron microscopy (TEM) methods were used to distinguish the aggregates for the CPZ/C₁₄Ab system in aqueous solutions above a certain mole fraction of the drug CPZ (α_CPZ = 0.2). Time-resolved fluorescence decay measurements of acridine orange revealed relative polarity near the head group regions of mixed micelle (CPZ/C₁₄Ab and CPZ/C₁₂DmCB) systems. The hydrophilic environment around the head group regions of the CPZ/C₁₄Ab system was different from that in the case of the CPZ/C₁₂DmCB system. On the other hand, several theoretical models were employed (Clint, Rubingh, Motomura, and SPB) for mixed micellar systems to elucidate the different interaction parameters. Such a systematic study of a zwitterionic gemini amphiphile and its interaction with other amphiphiles and an amphiphilic drug molecule is rare in the literature.