- Amphotericin B, a polyene macrolide antibiotic derived from Streptomyces nodosus, is well-known for its potent antifungal activity and is traditionally used systemically to treat severe fungal infections. However, its use in topical formulations has gained attention for localized infections due to its broad antifungal spectrum and relatively low potential for resistance development. Topical application is particularly advantageous in minimizing the systemic toxicity that is often associated with intravenous administration, such as nephrotoxicity and infusion-related reactions.
- Topical Amphotericin B is most commonly utilized in the management of superficial fungal infections, including cutaneous and mucosal candidiasis, particularly in immunocompromised individuals. It has demonstrated efficacy in treating oral thrush, vaginal candidiasis, and fungal infections of the skin, especially when caused by Candida species and some dermatophytes. Its poor solubility and permeability characteristics have historically limited its development for topical use, but advances in pharmaceutical formulations, such as liposomal gels, creams, and lozenges, have significantly enhanced its bioavailability and patient tolerability.
- Another important area of application for topical Amphotericin B is in ophthalmology, particularly for fungal keratitis caused by Fusarium, Aspergillus, or Candida species. In these cases, eye drops containing Amphotericin B (usually at 0.15–0.3%) are used to achieve high local concentrations directly at the site of infection. Despite its limited penetration into deeper ocular tissues, the drug remains a vital component of antifungal eye therapy due to its broad antifungal activity and the lack of equally effective alternatives.
- In recent years, research has also explored the use of Amphotericin B in topical formulations for treating cutaneous leishmaniasis, where the drug targets the Leishmania parasites residing in the dermis. Encapsulated or nanoparticle-based delivery systems have been investigated to improve dermal penetration and minimize irritation. While still not as widespread as systemic antileishmanial therapies, topical Amphotericin B has shown promise in experimental and clinical settings, especially in combination therapy or in regions with resistance to first-line drugs.
