An unusual entrapment of ciprofloxacin by anionic-hydrophilic and cationic-hydrophilic mixed micellar system through complex formation

The interaction of antibiotic ciprofloxacin (CPX) with two mixed micellar systems comprising nonionic amphiphilic surfactant (Pluronic F127) and either anionic (SDS) or cationic surfactant (CTAB) in an aqueous medium was studied using UV-visible spectroscopy, Fourier-transform infrared spectroscopy, as well as conductivity, dynamic light scattering, and ζ-potential measurements. An increase in absorbance values for both the mixed micellar—CPX systems compared to that of the single micelle—CPX system indicated better encapsulation efficiency of the former. The conductance properties of both micellar systems based on the ionic surfactants did not change after encapsulation of CPX. There was intermediate value of ζ-potential and diameters of the mixed micelles compared to both the single micelles as seen from the ζ-potential and DLS measurements. Successful entrapment of CPX is confirmed by an increase in the mixed micellar diameter from 3.13 to 3.31 nm for the SDS—F127 system and from 2.68 to 4.27 nm for the CTAB—F127 system.