Oxiconazole Nitrate is a broad-spectrum imidazole antifungal API used in pharmaceutical formulations for the topical treatment of superficial fungal skin infections. It belongs to the imidazole class of antifungal agents and acts primarily by interfering with fungal ergosterol biosynthesis.
Oxiconazole nitrate is the nitrate salt of oxiconazole and has the molecular formula C18H13Cl4N3O·HNO3 with a molecular weight of 492.14 g/mol. Its CAS Registry Number is 64211-46-7 and its FDA GSRS/USP identity is associated with UNII RQ8UL4C17S. USP defines Oxiconazole Nitrate as containing 98.0% to 102.0% of oxiconazole nitrate, calculated on the dried basis.
Oxiconazole nitrate is described as a nearly white crystalline powder. It is soluble in methanol, sparingly soluble in ethanol, chloroform and acetone, and very slightly soluble in water.
The USP monograph gives the molecular formula, molecular weight and chemical name, while current FDA labeling confirms the physical description and solubility characteristics.
The numerical values above are taken from the USP 2025 monograph reproduction and official USP preview.
Oxiconazole nitrate exerts its antifungal effect primarily by inhibiting ergosterol biosynthesis in fungal cells.
FDA labeling describes oxiconazole nitrate as an imidazole derivative whose antifungal activity is primarily associated with inhibition of ergosterol biosynthesis.
Oxiconazole Nitrate API is primarily used for development and manufacture of topical antifungal pharmaceutical products.
Its pharmaceutical applications include:
Current FDA labeling identifies oxiconazole nitrate cream as a topical dermatologic product.
Oxiconazole has demonstrated in-vitro activity against several clinically relevant fungal organisms.
Its activity includes organisms associated with:
Oxiconazole nitrate is incorporated into topical dosage forms because its pharmacological activity is intended primarily at the skin and superficial tissues rather than as a systemic antifungal treatment.
Oxiconazole nitrate is a highly chlorinated aromatic imidazole compound with low aqueous solubility.
FDA labeling confirms the solubility profile of oxiconazole nitrate.
Oxiconazole nitrate has a well-defined USP analytical profile.
USP identification includes:
The infrared spectrum must conform to the appropriate reference standard, while the oxiconazole peak in the sample must correspond to the standard solution used for the assay.
The current USP method uses liquid chromatography.
Key chromatographic parameters include:
These are USP monograph parameters and are therefore considerably stronger than generic commercial specifications.
The USP monograph provides specific limits for five related compounds:
The USP monograph identifies the related compounds chemically, including the E-isomer, oxime-related compound, hydrochloride-related compound, dichlorophenylmethanol and dichlorobenzyl chloride.
The USP specification for residue on ignition is:
NMT 0.2%
This test controls the amount of inorganic residue remaining after ignition of the API.
The USP monograph specifies:
NMT 1.0%
The test is performed by drying the sample at 105°C for 4 hours.
The USP monograph specifies pH using a 10 mg/mL suspension in water, rather than a 1% solution.
The acceptance range is:
pH 3.0–4.0
This distinction is important for your CMS because the standard CMS field says “pH (1% Solution),” whereas the actual USP procedure uses a 10 mg/mL suspension.
Oxiconazole nitrate is a crystalline material, and the physical form is relevant to pharmaceutical development. FDA's current product information describes it as a nearly white crystalline powder. FDA's topical-product guidance also identifies particle size distribution, crystal habit and polymorphic form as relevant Q3 characteristics for oxiconazole nitrate topical products.
Therefore, pharmaceutical development may appropriately include:
Oxiconazole Nitrate has a dedicated USP-NF monograph, making USP the preferred source for the principal API specifications.
The current USP specification includes:
The USP assay requirement is 98.0–102.0% on the dried basis, while the total organic impurity limit is NMT 0.5%.
| Parameter | Specification |
|---|---|
| Appearance | white to off-white crystalline powder |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 98.0% – 102.0% |
| Loss on Drying | NMT 1.0% |
| Residue on Ignition | NMT 0.2% |
| pH (1% Solution) | 3.0 – 4.0 |
| Individual Impurity | NMT 0.10% |
| Total Impurities | NMT 0.50% |
| Melting Point | Approximately 159–163°C |