SYNTHESIS, CHARACTERIZATION AND APPLICATION OF BIOPOLYMERIC HYDROGELS IN DRUG DELIVERY

Abstract

The increasing demand for targeted and controlled drug delivery systems has led to significant interest in the development of biopolymer-based hydrogels, which offer a versatile and biocompatible platform for enhancing therapeutic efficacy and minimizing side effects. This thesis focused on the synthesis and characterization of biopolymer-based hydrogels, with emphasis on their drug delivery applications. Different characterization techniques, i.e., Fourier Transform- Infrared spectroscopy (FTIR), Powder X-ray Diffraction (PXRD) and Scanning electron microscopy (SEM), were used for the detailed characterization of all synthesized hydrogels. The carboxymethyl tamarind kernel gum/polyvinylpyrrolidone/polyacrylamide (CMTKG/PVP/PAM) hydrogel was synthesized via free radical mechanism and its potential for diclofenac sodium (DS) release was studied. The presence of PVP was found to enhance the drug entrapment efficiency (65.54%) of the CMTKG/PVP/PAM hydrogel. The synthesized DS-loaded CMTKG/PVP/PAM hydrogel demonstrated the targeted delivery of DS in the colon (pH 7.4). The research then proceeds with the development of another novel hydrogel with xanthan gum (XG) as a biopolymer, focusing on the delivery of an ibuprofen drug. The addition of PVP enhances the hydrogel properties, such as gel fraction (91.88%), swelling (1100%), porosity (78.35), drug loading (21.38%), and drug release (80.2%). Moreover, the hydrogels based on β-cyclodextrin (β-CD), CMTKG and PAM were developed using polyethylene glycol diacrylate as a cross-linker. The synthesized β-CD/PAM/CMTKG hydrogel showed controlled and prolonged indomethacin release (62.49 %) upon the incorporation of β CD into the polymeric matrix. The thesis further explored the hydrogel microspheres based on tragacanth gum, β-CD and sodium alginate (TG/β-CD/SA) and studied its potential in the release of aspirin. The physical crosslinking technique, i.e. ionotropic gelation, has been employed for the fabrication of the TG/β-CD/SA hydrogel microsphere. The resulting hydrogel microsphere demonstrated controlled drug release (59.9%), complete degradability (100%) and non–toxic (87.9% cell viability) behavior. Moreover, the structural integrity of TG/β-CD/SA hydrogel was confirmed

vi by FTIR and PXRD analysis. Lastly, the research focused on the development of a nanocomposite hydrogel microsphere for curcumin delivery. The synthesized CMTKG/SA/copper oxide nanocomposite hydrogel revealed a slow and prolonged release profile (52.3%) for curcumin, due to addition of copper oxide nanoparticle into the hydrogel matrix. Overall, this thesis highlights the synthesis, characterization and potential of biopolymer-based hydrogels in hydrophobic drug delivery. Their non toxic and pH-sensitive properties demonstrate their ability to provide a biocompatible and targeted drug delivery system, effectively enhancing the therapeutic efficacy of hydrophobic drugs.