Objective: The objective of the present study was to synthesize the hydrogel from natural polymer and evaluation of its physical and chemical properties. Methods: Hydrogel was synthesized using graft co-polymerization technique from wheat starch, by crosslinking with acrylic acid. The product was purified, dried and micronized. It was then evaluated for water absorption and retention property at varying pH, FTIR, PXRD and Thermal analysis, microscopic, micromeritic and stability studies etc. Furthermore, the effect of NaOH treatment on prepared hydrogel material was studied. Results: Result of the studies revealed that superabsorbent hydrogel (SAH) product shows good water absorption capacity of 120g/g at neutral pH. Maximum water absorption capacity was at pH 9 which is 146.28g/g. Product shows good thermal stability, less cohesiveness and is amorphous in nature. In hygroscopicity study weight gain by SAH was 6.65% only while for unpurified SAH and NaOH treated SAH, it was 10.5% and 23.42% respectively. NaOH treatment shows a decrease in water absorption capacity by more than 40% also there is change in surface morphology of the product. Additionally, hygroscopicity was more and degradation rate was faster for NaOH treated hydrogel. Conclusion: Crosslinking with acrylic acid can form superabsorbent hydrogel material from the natural polymer such as wheat starch. The product shows excellent water absorption and retention capacity. pH affects water absorption capacity and shows maximum at pH 9 and at lower and higher pH it decreases to a significant level. There was decline in water absorption capacity and increase in hygroscopicity, when NaOH treatment is given to the SAH powder.

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.

The marine ecology is diverse with innumerable types of natural substances, both of plant and animal origin. Padina tetrastromatica (PT) (Hauck) is a brown algae belonging to the order Dictyotales, found in coastal region. The objective of present investigation was to evaluate phytochemical profile of extracts of PT. The air dried plant material was defatted and extracted successively with solvents of increasing polarity. Incumbent study was performed with standard qualitative phytochemical tests and HPTLC fingerprint analysis using CAMAG HPTLC system. The results showed the presence of phytoconstituents like sterols, terpenoids, flavonoids, glycosides, alkaloids and carbohydrates. Furthermore, components present in extracts were resolved in best possible solvent system by HPTLC. The chloroform extract of PT displayed eight peaks, in which those with Rf values 0.28 and 0.72 were more predominant. Whereas ethanol extract of PT exhibited nine peaks, in which maximum Rf value was found to be 0.82. In conclusion, the data of this study provide useful guide and suitability for investigation of biological activity of the plant according to the phytochemical groups observed. However, further work is needed to standardize the above chemical constituents in comparison with biomarker and this result can also be measured along with the other data for setting up the standards to this plant.