SUSTAINABLE SYNTHESIS AND CHARACTERIZATION OF TUNABLE AND MULTIPURPOSE NANOCELLULOSE FROM FRESHWATER AQUATIC WEED AS PHARMACEUTICAL EXCIPIENT

Abstract

Objective: The main objective of this work was to understand the basic properties of crystalline nanocellulose (CNC) that can be useful as a novel excipient in pharmaceutical formulations. This covers the isolation and preparation of nanocellulose followed by characterization. Methods: Cellulose was isolated from aquatic weed by autoclaving and bleaching. Cellulose to CNC conversion involved gluconic acid treatments at different concentrations (40%, 50% and 60%) followed by centrifugation and neutralization. CNC was further characterized by Differential Scanning Calorimetry (DSC) and Thermo gravimetric Analysis (TGA), Field Emission Scanning Electron Microscopy (FE-SEM) and Atomic Force Microscopy (AFM) for surface morphology, elemental analysis by Energy Dispersive Spectroscopy (EDS), Fourier Transform Infrared Spectroscopy (FTIR), crystallinity index by X-Ray Diffraction (XRD), and optical microscopy. Results: Acid concentration affects the moisture uptake, particle size, and yield of CNC. CNC size ranged from 350 nm to 900 nm with a crystallinity index 80% to 85%. Moisture uptake was 6.38±0.12% at 33% relative humidity. DSC and TGA established thermal stability over 200 °C. Nanocellulose has shown Angle of repose (28.81°), Carrs index (12.32), zeta potential (33mV) values and heavy metals within pharmacopoeial limits. Conclusion: CNC from water hyacinth was prepared successfully by sustainable process. CNC physico-chemical characterization revealed the stable nature of CNC, suitable to be used as an excipient in pharmaceutical formulations.