Developing poly(Agar-co-Glycerol-co-Thyme Oil) based organo-hydrogels for the controlled drug release applications

Abstract

In this study, it was aimed to investigate the synthesis, characterization and drug release behaviors of organo-hydrogels containing pH-sensitive Agar (A), Glycerol (G), Thyme Oil (TO). The novel organo-hydrogels containing TO were prepared in an emulsion media by the free-radical polymerization and crosslinking reactions among Agar (A), Glycerol (G), TO, N, N, methylenebisacrylamide (MBA) or glutaraldehyde (GA) reagent. Swelling ability (ethanol, acetone, ethanol/ID water (1:1), acetone/ID water (1:1) and gasoline environments and different pH), Fourier Transform Infrared Spectroscopy (FTIR) analysis and 5-Fluorouracil (5-Flu) drug release of the organo-hydrogels were profoundly determined and some structural parameters for organo-hydrogels such as blood clotting, hemolysis analysis, antioxidant analysis were also evaluated in this study. The FTIR spectra confirmed that the TO was bonded onto the organo-hydrogel structure, and the A, G and TO macromolecular chains interpenetrated through the MBA or GA reagent. When swelling analyzes were examined, it was determined that organo-hydrogels, which added thyme oil to the structure, swelled not only in pure water and tap water but also in organic solvents such as ethanol, acetone, ethanol/ID water (1:1), acetone/ID water (1:1) and gasoline. All of the organo-hydrogels synthesized in the light of blood clotting, hemolysis analysis, antioxidant analysis were hemocompatible and could be used within the body. The release results indicated that the organo-hydrogel p(AG-m-TO)3 and p(AG-g-TO)3 had the highest 84.3% and 73.3% release capacity. In addition, it was reported that the release capacities of organo-hydrogels were inversely proportional to the increased amount of TO. When 5-Flu drug release was examined in terms of kinetic models, it was observed that the release adapted to the Korsmeyer-Peppas (KPKM) model. And it was also determined that organo-hydrogels based on p(AG-m-TO) comply with the non-Fick law and organo-hydrogels based on p(AG-g-TO) comply with the Case II transport. In the light of the results obtained, their easy formability, their appropriate mechanical and physical properties make Organo-hydrogels suitable candidates for drug delivery systems.