Nano‐Vehicles for Drug Delivery Using Low‐Cost Cationic Surfactants: A Drug Induced Structural Transitions

Tailor‐made application of catanionic aggregates as drug delivery vehicle and as templates for organized nano‐assemblies makes them the best alternatives to liposomes and niosomes. Catanionic aggregates formed by using hydrotropic drug as one of the components pave way for the increased bioavailability thorough sustained contact time and release of the charged drug. In the present investigation, the molecular interaction between the anti‐inflammatory hydrotropic drug, diclofenac sodium (DS) with traditional low cost cationic surfactants with varying chain length is studied. A strong structural transition was observed using turbidity, viscosity, dynamic light scattering, zeta potential, 1 H‐NMR, AFM, TEM and SANS techniques. The results suggested that spherically/elliptical shaped micellar aggregates are converted into vesicles through intermediate cylindrical/wormlike aggregates. We have characterized (size and shape) the drug‐surfactant system based on the concentration of the drug, and alkyl chain length of cationic surfactants. The drug loaded vesicles were tested at physiological temperature and were found to stable even at high loading. Due to low cost and high stability, present system could be used as low cost drug delivery vehicle.