Quick Facts
| CAS Number | 23593-75-1 |
|---|---|
| Molecular Formula | C22H17ClN2 |
| Molecular Weight | 344.84 |
| Pharmacopoeia | USP/EP/BP |
| Packaging | 25 KG/DRUM |
Product Overview
Clotrimazole was discovered in 1969 by a research team led by Dr. Karl Heinz Büchel at Bayer AG in Germany, as part of a broad antifungal drug discovery program targeting the imidazole chemical class. It was the first clinically successful imidazole antifungal, establishing a molecular scaffold that would later give rise to miconazole, econazole, ketoconazole, and the entire azole antifungal family. Marketed initially as Canesten by Bayer, clotrimazole was rapidly adopted worldwide and today remains on the WHO Model List of Essential Medicines as a core topical antifungal agent.
Clotrimazole works by inhibiting lanosterol 14-alpha-demethylase (CYP51), a cytochrome P450 enzyme that converts lanosterol to ergosterol — the fungal equivalent of cholesterol in mammalian cells. By blocking ergosterol synthesis, clotrimazole causes toxic 14-alpha-methyl sterol accumulation and membrane permeability disruption, leading to leakage of essential intracellular contents. At low concentrations it is fungistatic; at higher concentrations achievable in topical formulations, it becomes directly fungicidal through membrane damage independent of CYP51 inhibition.
The drug's spectrum covers the three most important groups of fungal pathogens encountered in clinical practice: dermatophytes (Trichophyton, Microsporum, Epidermophyton — the causes of ringworm and athlete's foot), yeasts (Candida albicans and other Candida species — the causes of thrush and vaginal yeast infections), and Malassezia furfur (pityriasis versicolor). Clotrimazole also demonstrates useful antibacterial activity against Gram-positive cocci including Staphylococcus and Streptococcus species, making it effective in mixed skin infections. Its primary limitation is poor oral bioavailability due to extensive first-pass hepatic metabolism, which is why it was developed exclusively as a topical agent — a design feature that became a commercial strength in the OTC market.
As of mid-2026, the global clotrimazole market is driven by rising dermatophytosis prevalence (particularly tinea and onychomycosis in aging populations), expanding OTC antifungal product availability, and increasing vulvovaginal candidiasis incidence. China and India are the dominant API producers. KingWish supplies GMP-certified clotrimazole meeting USP, EP, and BP standards, supporting pharmaceutical manufacturers producing creams, vaginal tablets, oral troches, and OTC topical formulations worldwide.
Quality Specifications
| Assay (Potentiometric Titration) | 98.5%–101.0% on dried basis, per USP/EP |
|---|---|
| Melting Point | 141–145°C |
| Related Substances (HPLC) | Impurity A ≤ 0.2%; any other single impurity ≤ 0.10%; total ≤ 0.5% |
| Loss on Drying | ≤ 0.5% (100–105°C, 2 hours) |
| Sulfated Ash | ≤ 0.1% |
| Residual Solvents | Compliant with ICH Q3C; toluene ≤ 890 ppm |
| GMP Status | Manufactured under ICH Q7 GMP conditions |
Pharmaceutical Applications
Topical Formulations
1% cream, gel, lotion, solution, and powder for dermatophyte infections and cutaneous candidiasis. Particle size distribution is critical for formulation homogeneity and release kinetics.
Gynecological & Oral Forms
Vaginal tablets 100/200/500 mg for vulvovaginal candidiasis. Oral troches 10 mg for oropharyngeal candidiasis. Requires micronized API for consistent dissolution.
Therapeutic Areas
- Dermatology: Tinea pedis, tinea cruris, tinea corporis, pityriasis versicolor, cutaneous candidiasis
- Gynecology: Vulvovaginal candidiasis — single-dose and multi-day regimens
- Oral Medicine: Oropharyngeal candidiasis (thrush) prophylaxis and treatment, especially in immunocompromised patients
Sourcing Clotrimazole API: Key Checks
Documentation
Request CoA with HPLC chromatogram for related substances. Verify impurity A (benzhydrol derivative) is within limit. For topical-grade material, request particle size distribution data (D50 typically <25 um for creams). Confirm residual toluene levels.
Red Flags
. suggests degradation. Missing particle size data for topical-grade material. Prices significantly below market range (typical $40–$80/kg for GMP-grade).
Packaging & Logistics
Standard: 25 KG/DRUM with double LDPE liner. Store at room temperature (15–25°C), protected from light. Product is stable under normal conditions. Standard lead time 4–8 weeks.
Market Context
Global clotrimazole market driven by OTC antifungal demand and rising dermatophytosis prevalence. China and India dominate API production. Clotrimazole remains the most cost-effective topical azole — an important consideration for OTC and tender-market formulations. Market report