Development of Alcohol-Free Herbal Sanitizer Using Silver Nanoparticles: A Sustainable Approach to Hand Hygiene

Background: Hand hygiene is crucial for preventing infectious diseases, but conventional alcohol-based sanitizers cause skin dryness, irritation, and flammability concerns. Alcohol-free herbal sanitizers with silver nanoparticles (AgNPs) and plant extracts offer an alternative with antimicrobial properties, skin-friendliness, and sustainability. Method: An alcohol-free herbal sanitizer was formulated using AgNPs (50 ppm solution) and plant extracts including Aloe vera, Neem, Tea Tree Oil, Eucalyptus Oil, and Lemon Extract. Silver nanoparticles were synthesized via chemical reduction using sodium citrate and characterized using UV-visible spectroscopy, TEM, and DLS. The formulation was prepared by integrating herbal extracts and AgNPs into a thickened gel base with xanthan gum, glycerin, and Vitamin E. The antimicrobial activity was evaluated using the agar diffusion method and Minimum Inhibitory Concentration (MIC) determination. Stability tests were conducted at 25°C and 40°C over 30 days to assess physical consistency and microbial contamination. Results: The sanitizer exhibited a clear, gel-like consistency with no separation over 30 days. It demonstrated strong antibacterial activity, forming inhibition zones of 18 mm for E. coli and 20 mm for S. aureus. The MIC values were 5% for E. coli and 4% for S. aureus, confirming efficacy at low concentrations. The formulation maintained a skin-friendly pH of 5.5, ensuring safety for frequent use. Stability testing showed no microbial contamination or physical degradation. Conclusion: The alcohol-free herbal sanitizer with AgNPs and plant extracts is an effective, stable, and safe alternative to conventional sanitizers. It provides potent antimicrobial protection without skin irritation, making it a sustainable solution for frequent hand hygiene. Future research should explore its efficacy against a broader range of microorganisms and its potential for commercial production.