Application of pectin‑zinc oxide hybrid nanocomposite in the delivery of a hydrophilic drug and a study of its isotherm, kinetics and release mechanism

Pectin-based gel and its nanocomposite with zinc oxide have been compared for their capacity to release Donepezil for the possible use as an implantable drug delivery platform for the treatment of Alzheimer's disease. Adsorption capacities of the samples were determined as a function of pH, temperatures, concentrations of the drug, and the mass of the adsorbent. The nanocomposite exhibited significant adsorption compared to the parent gel. Adsorption data for the nanocomposite system fits well with Langmuir model and followed pseudo-first order kinetics, while that of the parent polymeric system followed pseudo-second-order kinetics. Donepezil adsorbed polymeric samples were prepared and evaluated for tensile strength, swelling index, folding endurance and characterized by FTIR, FESEM, EDS, XRD and TGA techniques. The desorption of zinc oxide was also monitored using the dynamic light scattering technique. The in vitro drug release study indicated desorption of Donepezil to the maximum extent of ~88% and 46% during 5 days period from the nanocomposite and the parent gel respectively. The developed systems showed negligible (<10%) percentage of hemolysis after incubation with sheep erythrocytes. In conclusion, the developed pectin-based nanocomposite can be explored as a potential platform for the development of implantable drug delivery systems for chronic diseases.