Climbazole Long-Acting Antifungal: Forms Stratum Corneum Reservoir via Lipophilicity for Sustained Anti-Dandruff Efficacy

Introduction to Climbazole

Climbazole (chemical name: Climbazole, also known as Chloromidazole) is an anti-dandruff and antipruritic agent developed by Bayer (Germany) in 1977. This compound exhibits unique antifungal properties, inhibiting Malassezia furfur (ovoid spore-forming bacteria or pityrosporum ovale) and Candida albicans, as well as dermatophytes such as Trichophyton. Additionally, Climbazole is highly suitable for formulation applications due to its stability under light and heat exposure and excellent solubility in organic solvents.

Key Characteristics:

• Low Toxicity: Climbazole is classified as a low-toxicity substance, though its addition significantly increases the viscosity of shampoos.
• Mechanism of Action: It eliminates external factors causing dandruff by killing and inhibiting fungal growth, thereby achieving anti-dandruff and antipruritic effects.
• Solubility and Stability: Non-hygroscopic, stable under light and heat, and readily soluble in organic solvents. Its water solubility is limited (5.5 mg/1000 ml), but it dissolves well in surfactant systems. Due to its ionic properties, it influences formulation viscosity. Climbazole remains stable in acidic and neutral solutions but partially hydrolyzes in alkaline conditions (pH > 9.2) and at elevated temperatures (>50°C).
• Performance Comparison: While its anti-dandruff and antipruritic efficacy is inferior to that of ZPT (Zinc Pyrithione) and Octopirox, its usage has declined in recent years.
• Regulatory Limit: The maximum allowable concentration in cosmetics is 0.5%.

Applications:

• Schwarzkopf (Schwarzkopf): Utilizes Climbazole in its anti-dandruff products.
• Clear (Qingyang): Combines zinc pyrithione (ZPT) and Climbazole to achieve synergistic effects.

Usage:
Climbazole is a racemic mixture composed of equal molar amounts of (R)- and (S)-Climbazole, with the IUPAC name (RS)-1-(4-chlorophenoxy)-1-(1H-imidazol-1-yl)-3,3-dimethylbutan-2-one. It is a locally applied antifungal agent used to treat human fungal skin infections. Climbazole is included in over-the-counter (OTC) anti-dandruff shampoo formulations and skin treatment compositions to address dandruff and eczema caused by fungal infections.

Notes:

• Despite its effectiveness in dandruff and antipruritic control, Climbazole’s usage has declined in recent years due to its comparative disadvantage in efficacy compared to ZPT and Octopirox.
• Maximum Allowable Concentration in Cosmetics: 0.5%.

Key Applications:

• Schwarzkopf incorporates Climbazole in its anti-dandruff products, while Clear (Qingyang) combines zinc pyrithione (ZPT) and Climbazole to achieve synergistic effects.

Regulatory Compliance: The maximum allowable concentration in cosmetics is 0.5%.