synthesis and characterization of pH-sensitive nanocomposite based on natural polymer -sodium alginate- extracted from marine brown alga Sargassum asperifolium collected from Jazan Coasts, KSA.

The pH-sensitive nanocomposite composed of sodium alginate/ Pectin/ Tannic acid - silver SA/Pec/TA-Ag was prepared using microwave irradiation and employed as a carrier for Propranolol drug. Physico-chemical characteristics of the prepared systems using Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Field Emission Scanning Electron Microscope (FESEM), High-Resolution Transmission Electron Microscope (HRTEM), Dynamic light Scattering instrument (DLS), and Energy Dispersive X-Ray Analysis (EDX). The percentage drug release was 96% at pH 7.4 within 420 min. The drug release data was fitted into different kinetic models included zero order, First order, Higuchi and Ritger-Peppas model. The release mechanism is non-Fickian character where it controlled by diffusion and relaxation of polymer chains. It can be concluded that SA/Pec/TA-Ag nanocomposite is candidate for the oral drug carrier specific for intestinal system and has stability against gastric fluid.