Evaluation of the effectiveness of natural extract as a substituent for synthetic preservatives and antioxidants in pharmaceutical preparations.

Background: Despite the fact that synthetic preservatives and antioxidants have strong antibacterial and antioxidant activity, they are frequently associated with negative health consequences. Currently, there is an increasing interest in pharmaceutical products that are excellent in quality and free of synthetic preservatives. Methods: As a result, the purpose of this research is to assess the antibacterial and antioxidant activities of olive leaf extract, oleuropein, and thymol in various pharmaceutical products. Furthermore, the efficacy of these natural extracts to substitute synthetic preservatives (methyl-propylparaben and benzalkonium chloride) and antioxidants (butylhydroxytoluene) will be investigated. Results: The results revealed that oleuropein, olive leaf extract, and a blend of oleuropein and thyme oil may be utilized as preservatives at concentrations of (0.6 % w/v), (0.4 % w/v), and (0.4 %/0.1 % v/v), respectively. The results demonstrated that thyme oil and oleuropein have synergistic efficacy against the studied microorganisms. By assessing antibacterial activity, and physical properties, the results demonstrated that pharmaceutical formulations containing natural preservatives were stable and effective for three months under accelerated settings (40 °C/75 % RH). Conclusion: Natural compounds such as oleuropein, olive leaf extract, and thyme oil have shown antibacterial effectiveness equivalent to synthetic preservatives in selected pharmaceutical products. Furthermore, there was synergy in antimicrobial activity between thyme oil and oleuropein and this facilitates the use of these compounds at different levels.