Formulation of Herbal Gel of Antirrhinum majus Extract and Evaluation of its Anti- Propionibacterium acne Effects.

Background: Antirrhinum majus contains aurone with excellent antibacterial and antifungal activities. In addition, visible light activates the endogenous porphyrins of Propionibacterium acne , which results in bacterial death. Therefore, considering the above-mentioned facts, the aim of the present study was to prepare a topical herbal gel of A. majus hydroalcoholic extract and to evaluate its antiacne effects with or without blue light combination as an activator of the porphyrins.

Materials and Methods: Antibacterial activity of the shoot or petal extracts was evaluated by disc diffusion method and the minimum inhibitory concentration (MIC) was calculated. Various gel formulations were developed by the Experimental Design software. The obtained gel formulations were prepared and tested for pharmaceutical parameters including organoleptic features, pH, viscosity, drug content, and release studies. Finally, the antibacterial activity was evaluated against ( P. acnes ) with or without blue light.

Results: The MIC of the extracts showed to be 0.25 μg/ml. Evaluation of the gel formulation showed acceptable properties of the best formulation in comparison to a gel in the market. Pharmaceutical parameters were also in accordance with the standard parameters of the marketed gel. Furthermore, statistical analyses showed significant antibacterial effect for gel when compared to negative control. However, combination of blue light with gel did not show any significant difference on the observed antibacterial effect.

Conclusion: Because of the statistically significant in vitro antiacne effects of the formulated gel, further clinical studies for evaluation of the healing effects of the prepared gel formulation on acne lesions must be performed.