Abstract

Ucheokoro Adaeze S.*, Jackson Tenderwealth C.

ABSTRACT

Background: The emergence of antimicrobial resistance and limitations associated with conventional dosage forms of metronidazole necessitate innovative drug delivery strategies. Green nanotechnology offers an eco-friendly approach to improving drug physicochemical properties and therapeutic performance. Objective: This study aimed to develop and characterize metronidazole-loaded silver nanoparticles synthesized using aqueous fruit extracts of Carica papaya and Musa acuminata as natural reducing and stabilizing agents. Methods: Fruit extracts were prepared by aqueous maceration and reacted with silver nitrate solution in the presence of metronidazole to produce nanoparticle formulations. The synthesized nanodrugs were evaluated for physicochemical properties (pH and solubility), morphology using Scanning Electron Microscopy (SEM), thermal behavior by Differential Scanning Calorimetry (DSC), functional group interactions through Fourier Transform Infrared Spectroscopy (FTIR), and optical properties using Ultraviolet–Visible (UV–Vis) spectroscopy. Results: The formulations exhibited mildly acidic pH values (5.5–5.7) and were soluble in water, methanol, ethanol, dilute hydrochloric acid, chloroform, and acetone. SEM analysis revealed predominantly spherical nanoparticles with surface roughness, indicating increased surface area. DSC thermograms showed a reduction in melting point from 116 °C (pure metronidazole) to 88.5–91 °C in the nano-formulations, suggesting reduced crystallinity and successful drug incorporation. FTIR spectra confirmed the presence of hydroxyl and carbonyl groups, indicating phytochemical capping and drug–nanoparticle interactions. UV–Vis spectra displayed characteristic surface plasmon resonance bands between 272–407 nm, confirming silver nanoparticle formation and drug loading. Conclusion: Fruit-mediated green synthesis successfully produced stable metronidazole-loaded nanoparticles with modified physicochemical and structural properties, demonstrating potential for improved antimicrobial drug delivery.