Comparative in vitro evaluation of anti-inflammatory properties of selenium disulfide and ketoconazole-based topical formulations

Background: Seborrheic dermatitis and dandruff are chronic inflammatory scalp disorders associated with cytokine- mediated immune responses and impaired barrier function. Methods: This in vitro study compared the anti- inflammatory efficacy of two topical formulations—Selsun S (1% selenium disulfide + 3% salicylic acid) and a comparator (2% ketoconazole + 2% salicylic acid)—using THP-1 monocytic cells. Both formulations significantly suppressed TNF-α production (IC₅₀ <0.03 mg/ml), with the comparator (2% ketoconazole + 2% salicylic acid) exhibiting higher cytotoxicity. Results: Selsun S demonstrated greater potency in reducing IL-6 (IC50: 0.033 mg/ml versus 0.041 mg/ml) and IL-8 (IC50: 0.032 mg/ml versus 0.045 mg/ml), likely due to enhanced skin penetration from its higher salicylic acid content. Conclusions: These findings support Selsun S’s superior anti-inflammatory activity and tolerability, indicating its potential utility in managing inflammatory scalp conditions.