In vitro solubilization of antibiotic drug sulfamethazine: An investigation on drug–micelle aggregate formation by spectroscopic and scattering techniques

Abstract

AbstractMicellar solubilization has been used extensively for the dissolution of sparingly soluble drugs for effective drug delivery. Apart from improving the solubility and bioavailability, micelles can help reduce toxicity and improve permeability in the system. In this article, solubilization of a well‐known antibiotic, sulfamethazine (SMZ) upon micellization, is studied by employing various spectroscopic and scattering techniques like, ultraviolet–visible, fluorescence, small angle neutron scattering (SANS), and zeta potential (ZP) studies. The size(s) and charge(s) of the micelles were monitored by SANS and ZP. A positively charged/cationic surfactant, cetyl trimethyl ammonium bromide (CTAB) and a negatively charged/anionic surfactant, sodium dodecyl sulfate (SDS) are used for micelle formation. Regardless of the surfactant type, the solubility of SMZ increases linearly with the increase in the surfactant concentration, as a result of association between the drug and micelles. However, the solubility of SMZ is found to be better with CTAB than SDS. Upon interaction with SMZ, we observed that the critical micelle concentration of CTAB occurred at a lower concentration than that of SDS surfactant. As fitted in the ellipsoidal core–shell model, SANS results also show the formation of charged micelles. This comparative study can help us to select an appropriate medium for SMZ solubilization to improve selective drug delivery in biomedical applications.