Hybrid hydrogel systems of micelles of drug anion containing ionic liquid and biopolymers: Rheological behavior and drug release

Abstract A novel solution blend approach was tried to prepare hybrid gels consisting of viscoelastic gels of ionic liquid (IL) type, 1-dodecyl-1-methylpiperidinium acetylsalicylate, [C 12 mpip][AcSa] in sodium salicylate (SS) aqueous media on one hand and three individual samples of biopolymers namely agar, chitosan with low (L) and medium (M) molar mass in aqueous media. The as prepared gels were characterized by rheomechanical spectra by constructing the profiles of moduli vs frequency at two different temperatures of (293.15 and 310.15) K and also moduli vs temperature profiles to locate the gel temperatures. The results were interpreted in terms of weak physical networks formed due to the large entanglement and straightening of biopolymer chains. The sol-gel transition was thermo-irreversible. The blended solutions of viscoelastic micellar gels with biopolymer aqueous solutions or biopolymer solutions dissolved in micellar solutions were also characterized by dynamic rheological measurements and the trends are explained. The release of the drug anion from the gel and their dry cast films was monitored and the data were modeled to explain the release mechanism.