Development and In Vitro Evaluation of an Antifungal Ointment Formulated from Erigeron floribundus Leaf Extracts Against Trichophyton rubrum

Background: Dermatophytoses are superficial fungal infections affecting keratinized tissues and remain a significant public health concern, particularly in tropical regions. The emergence of antifungal resistance and limited access to conventional drugs underscore the need for cost-effective phytotherapeutic alternatives.

Objective: This study aimed to develop and evaluate the in vitro antifungal activity of a topical ointment formulated from ethanolic leaf extracts of Erigeron floribundus against Trichophyton rubrum.

Methods: Aqueous and ethanolic extracts were prepared by maceration (powder:solvent ratio 1:5 w/v) for 72 hours. Phytochemical screening included qualitative tests and quantitative determination of total polyphenols (Folin–Ciocalteu method) and flavonoids (aluminum chloride assay). Antifungal activity was evaluated by agar diffusion and broth microdilution methods (MIC and MFC, n = 3). Ointments containing 2% and 5% (w/w) ethanolic extract were prepared in a hydrophobic base (vaseline, lanolin, paraffin oil, glycerol, lecithin, vitamin E) and assessed for organoleptic properties, homogeneity, stability, and in vitro antifungal activity.

Results: Extraction yields were 4.43% (aqueous) and 4.89% (ethanolic). Phytochemical analysis revealed polyphenols, flavonoids, saponins, and glycosides in both extracts; alkaloids were present only in the ethanolic extract. The ethanolic extract showed superior antifungal activity (MIC = 1.87 ± 0.12 mg/mL; MFC = 6.25 ± 0.25 mg/mL) compared to the aqueous extract (MIC = 3.75 ± 0.18 mg/mL; MFC = 12.5 ± 0.35 mg/mL). The MFC/MIC ratio (≤4) indicated fungicidal activity. The 5% ointment produced an inhibition zone of 18 ± 0.5 mm against T. rubrum.

Conclusion: The ethanolic extract of E. floribundus demonstrated significant in vitro antifungal activity, retained efficacy in a topical ointment, and represents a promising candidate for phytotherapeutic management of dermatophytoses. Further in vivo studies and clinical trials are warranted .