A proof of concept for the micellization of quercetin with anionic surfactants: Effect of counter ion

Strength of interaction of sodium/ammoniumdodecyl sulfates (SDS and ADS; CH3(CH2)10CH2SO4Na/ CH3(CH2)10CH2OSO3NH4) with quercetin (QCT) through micellization is investigated. The strength and mode of interaction of QCT with SDS/ADS was analyzed using uv-visible, FTIR, and NMR spectral techniques. Charac-teristics of QCT/SDS and QCT/ADS micelles was determined by estimating the critical micellar concentration, particle size and zeta potential values. Thermodynamic parameters & UDelta;G0m and & UDelta;S0m suggest that the micelli-zation of QCT/ADS occurs more spontaneously than QCT/SDS micellization. The small size of head group (-Na+) in SDS exhibits higher steric repulsion upon forming micelles with QCT, whereas the big size head group (-NH4+) in ADS exhibits strong micellization due to additional hydrogen bonding. The results suggests that ADS would be useful in developing QCT based skin formulations which could reduce the risk of surfactant penetration in skin. In this paper we have reported a second cmc of ADS as 0.6 mM which is probably for the first time.