Tabriz University of Medical Sciences Advanced Pharmaceutical Bulletin 2228-5881 15 3 2025 09 25 Evaluating the Efficacy of a Semi-Solid Formulation with Clove Oil and Curcumin versus Clindamycin in the Treatment of Acne Vulgaris: A Comprehensive Study of Preclinical and Clinical Findings 606 616 10.34172/apb.025.45153 EN Peymaneh Dastgir https://orcid.org/0009-0001-2648-0976 Setareh Tehrani https://orcid.org/0000-0002-6197-4461 Setareh Haghighat https://orcid.org/0000-0002-6605-5245 Sepideh Arbabi Bidgoli https://orcid.org/0000-0003-4830-8680 Solmaz Ghaffari https://orcid.org/0000-0002-5166-5112 Journal Article 10.34172/apb.025.45153 2025 01 15 2025 08 15 Purpose: Acne vulgaris is a chronic inflammatory condition affecting the pilosebaceous units. With the rise of antibiotic resistance and the potential side effects associated with conventional treatments, there is increasing interest in exploring natural alternatives for treating acne. This study aimed to formulate and clinically evaluate a topical gel containing clove oil and curcumin in patients with mild to moderate acne vulgaris, using topical clindamycin as a standard comparator. Methods: The antibacterial activity of clove oil and curcumin against Propionibacterium acnes and Staphylococcus epidermidis was assessed by determining their minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Based on these findings, semisolid gel formulations were developed and subjected to in vitro evaluations. Subsequently, a single-blind, randomized, comparative clinical study was conducted in 31 participants diagnosed with mild to moderate acne. Volunteers applied clindamycin gel in the morning and the clove oil–curcumin gel in the evening, or vice versa, over a 4-week period. Clinical outcomes, including acne lesion counts, Acne Severity Index (ASI), and patient satisfaction, were assessed. Results: The clove oil-curcumin gel demonstrated comparable efficacy to clindamycin in reducing acne lesions, papules, and ASI. While no significant differences were observed between the two groups in comedone reduction, patient satisfaction increased in clove oil-curcumin gel group. Conclusion: Topical application of a gel containing clove oil and curcumin demonstrated promising results as an effective and well-tolerated alternative or adjunctive therapy for acne vulgaris. These findings support the potential of plant-based formulations in acne management.