• Surfactant tail length dependence of the photophysics and dynamics of a chemotherapeutic drug within anionic micellar aggregates

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      https://www.ias.ac.in/article/fulltext/jcsc/133/0039

    • Keywords

       

      Norfloxacin; Anionic micelle; Varying tail length; Structural dynamism of NOF; Rotationalrelaxation dynamics; Hydrophobicity favors cationic form of NOF.

    • Abstract

       

      The present work reports a photophysical study of norfloxacin (NOF), an efficient chemotherapeuticantibacterial drug, in well-characterized biomimetic micellar aggregates of anionic surfactants. Themajor focus of the present investigation lies in deciphering the effect of the surfactant chain length on thestructural dynamics of the drug within a micelle-encapsulated state through steady-state and time-resolvedfluorescence spectroscopic techniques. The anionic surfactants employed for the purpose are decyl sodiumsulfate (S10S), dodecyl sodium sulfate (S12S) and tetradecyl sodium sulfate (S14S). Our experimental resultsevince that increasing hydrophobic surfactant tail length exerts a profound influence on promoting a specificprototropic form of NOF within the micellar aggregates; an apparently enigmatic observation is thatincreasing hydrophobicity of the micellar microheterogeneous system indeed favors the cationic species ofthe drug. This is interpreted on the basis of electrostatic stabilization between the drug (cationic form) andanionic surface charge of the as-employed micellar assemblies, while the micellar hydration model fails torationalize the experimental findings. Particular emphasis is also given on delineating the probable locationand the modulated rotational-relaxation dynamics of the drug molecule within the micellar aggregates.

    • Graphical Abstract

       

      The interaction thermodynamics and dynamics of norfloxacin within anionic micelles is critically dependent on the tail length of the surfactant such that the micellar hydration model is found to be inadequate to explain the photophysics of the drug whereas electrostatic interaction appears to play the governing role.

    • Author Affiliations

       

      BIJAN K PAUL1 NARAYANI GHOSH2

      1. Department of Chemistry, Mahadevananda Mahavidyalaya, Barrackpore, Kolkata 700 120, India
      2. Basic Science and Humanities Department, University of Engineering and Management, University Area, Newtown, Kolkata 700 156, India
    • Dates

       
  • Journal of Chemical Sciences | News

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