Abstract

The current work aims to develop and evaluate hydrogel containing silver nanoparticles with Withania coagulans aqueous extract. The silver nanoparticles and silver nanoparticles with Withania coagulans were prepared by a green synthesis approach using 0.1 mM silver nitrate solution and a 1 % aqueous extract of Withania coagulans. The silver nanoparticles were used for characterization purposes, whereas the silver nanoparticles with Withania coagulans were incorporated in the hydrogel formulation containing carbopol 971P NF of different concentrations, propylene glycol, triethanolamine and distilled water of appropriate amount. The silver nanoparticles were evaluated for their particle size (Z_avg), polydispersity index, surface morphology by scanning electron microscopy and high-resolution transmission electron microscopy. The prepared hydrogels were assessed for physical appearance, pH, viscosity, syneresis, spreadability, occlusivity, and drug-excipient compatibility. The synthesized silver nanoparticles were stable and spherical in shape with an average particle size of 174.9±0.062 nm, indicating the particles were in the nano range and the polydispersity index value of 0.174±0.054 showed the homogeneity of particle size distribution. The scanning electron microscopy and high-resolution transmission electron microscopy data reflected the spherical and smooth surface of silver nanoparticles. Energy-dispersive X-ray analysis spectra of silver nanoparticles showed a strong spectral signal of silver. The crystalline nature of the silver nanoparticles was confirmed from the spot pattern obtained by selected area electron diffraction. The silver nanoparticles with Withania coagulans loaded hydrogel formulations (F1, F2 and F3) were found to be yellowish-brown in color, homogeneous in nature, with pH of 6.24±0.047-6.78±0.082 and percentage syneresis from 0.46±0.074 to 1.47±0.12. The spreadability data (4.83±0.08-6.4±0.124 cm) indicated the easily spreadable nature of hydrogel and the viscosities in the range of 41840±257.07-87538±389.87 cp were found to be suitable for topical application. The percntage occlusiveness of the prepared hydrogel was found to be 54.43±1.24 to 74.82±2.48. The drug excipient compatibility by attenuated total reflectance-fourier transform infrared spectroscopy spectroscopy revealed the compatibility of the extract with the hydrogel formulation components.