In-vitro Antibacterial Activity of Carbopol-Essential Oils hydrogels

  • Esam Yahya USM
  • Muhanad Abdullah Abdulsamad


Background and Objectives: The main purpose of the drug therapy of any disease is to maintain the desired therapeutic concen-tration of the drug for the entire duration of the treatment. The aim of this study is to formulate mixed essential oils loaded hydrogel, and evaluate its antibacterial activity against some pathogens. Materials and Methods: Different hydrogels were formulated by using different concentration of essential oils. Antibacterial evaluation was done using disk diffusion method. Screening for antibacterial activity of essential oils were studied prior to hydrogel formulation to compare the changes in activity after incorporation in the hydrogel. Results: Clove oil exhibited the strongest activity towards all the tested pathogens, compared to other tested essential oils (clove > cinnamon > tea tree > rosemary). The formulation containing mixed essential oils showed the best results, with synergistic effect against all tested pathogens. Hydrogels were further subjected to evaluation of physical properties like color, clarity, pH, viscosity and animal skin irritation study. The zone of inhibition of the final formulation containing only 3% from the selected three essential oils was between 18‐23 mm for S. aureus, 17‐20mm for E. coli, and 14‐18mm for P. aeruginosa. The hydrogels were non-irritant, stable, and free of any microbes at room temperature. Conclusion: Activity of essential oils was much affected by incorporation in hydrogel. The loaded hydrogel showed better antimicrobial activity against all the microorganisms used in the study, despite the need for clinical studies to determine of the effectiveness and potential toxic effects in-vivo.