Development of a Calendula Officinalis-Based Emulgel as a Topical Herbal Therapy for Leg Ulcer Management: Formulation and In Vivo Assessment

Objectives: The study aimed to develop and evaluate a Calendula officinalis-based emulgel as a topical herbal therapy for chronic leg ulcer management, emphasizing anti-inflammatory and antimicrobial activity, stability, and patient acceptability. Methods: A 3² full factorial design was employed to optimize the emulgel formulations using varying Smix ratios (Span 20:Tween 20), oil, and water phase compositions. The optimized batch was selected based on drug release, antimicrobial, and anti-inflammatory activity. Formulations were assessed for organoleptic properties, pH, viscosity, spreadability, drug content, In-vitro drug release, skin irritancy, washability, and accelerated stability. Antimicrobial activity was evaluated against Staphylococcus aureus, and anti-inflammatory activity was assessed using the protein denaturation assay. Results: The optimized formulation, F5 (Smix 3:1, 1 mL oil, 1 mL water), demonstrated superior performance with the highest drug release (90.5 ± 3.4%), zone of inhibition (22.4 ± 0.5 mm), and protein denaturation inhibition (75.6 ± 1.1%). All batches exhibited pH within 5.76–5.78, viscosity between 15,800–16,500 cP, and spreadability around 5.5 cm. No irritation was observed during skin tests, and all batches were easily washable. The formulations remained stable over 3 months under accelerated conditions. Conclusion:The optimized Calendula officinalis emulgel exhibited excellent physicochemical stability and potent bioactivity, highlighting its potential as a costeffective and natural alternative for chronic leg ulcer treatment. These findings support future clinical translation of the formulation in wound care therapeutics.