Fungal nail infections, known medically as onychomycosis, represent one of the most widespread and frustrating nail disorders facing modern medicine. Beyond the physical discomfort, the discolouration, thickening, and brittleness of infected nails can cause visible disfigurement, often resulting in psychological distress and social embarrassment.
A range of treatments currently exists for onychomycosis affecting both fingernails and toenails, but they come with substantial limitations, including the potential for liver damage and adverse drug interactions, particularly with some oral antifungal medications.
Treatment can also be prolonged because successful management depends partly on the infected nail being gradually replaced by a newly grown, healthy nail. Recurrence is another important challenge.
Traditional topical creams, ointments, and lotions may also have difficulty reaching fungal organisms located deeper within the nail. These formulations can be easily wiped or washed away during daily activities before sufficient concentrations of the active medicine reach the deeper layers of the nail plate.
Now, a research team led by Nilesh Banarase, Vikrant L. Salode, Koshish Gabhane, and Hemant A. Sawarkar has formulated an herbal nail polish containing turmeric and henna extracts, as reported in a study published in the Journal of Phytomedicine and Therapeutics.
The two plant extracts were combined in an attempt to harness their potential antifungal activity in a formulation suitable for application to infected nails.
Curcumin, one of the principal constituents of turmeric, possesses antifungal, anti-inflammatory, and antioxidant properties. Laboratory research suggested that curcumin can inhibit fungal growth, although its safety and effectiveness as a treatment for human onychomycosis require appropriate clinical evaluation.
Henna is used as a natural dye for the skin, hair, and nails. Its leaves contain lawsone, a naphthoquinone compound that is responsible for much of its characteristic colouration. Lawsone has also demonstrated antifungal activity against various fungal strains in laboratory studies.
Rather than simply applying a mixture of these plant extracts to the nail, the researchers set out to design a film-forming system intended to improve retention, sustained release, and penetration of the active compounds.
Developing an effective nail polish requires carefully balancing the medicinal properties of the herbal formulation with its physical performance. Also, the polish must dry quickly, adhere strongly to the nail surface, resist water, and maintain an appropriate viscosity to facilitate delivery of its active ingredients through the nail plate.
Unlike oral antifungal medications, a topical herbal polish is intended to minimise systemic exposure, potentially reducing the risk of systemic adverse effects associated with orally administered drugs, including liver toxicity and drug interactions. However, topical formulations can still cause skin irritation or other adverse reactions, so their safety must be evaluated clinically.
The formulation, developed as part of a study published in the International Journal of Pharmaceutical Sciences, was designed to deliver antifungal plant constituents directly to the nail. It also contains excipients such as hydroxypropyl methylcellulose, thioglycolic acid, menthol, propylene glycol, and ethanol.
Unlike ordinary cosmetic nail polish, the medicinal formulation is designed so that, after application, the solvent evaporates and leaves behind a thin film. This film acts as a reservoir, allowing the active compounds to remain in contact with the nail surface and potentially release gradually over time. Such a system may improve retention and reduce the need for frequent reapplication.
The research team developed eight distinct trial formulations, designated F1 through F8, using a trial-and-error approach to optimize the proportions of plant extracts and selected pharmaceutical excipients.
Following laboratory testing of each experimental batch, Formulation F7 emerged as the optimal blend, exhibiting a desirable balance of film stability, drying time, and physical durability.
The researchers also evaluated the antifungal activity of Formulation F7 against Candida albicans, a common yeast that can cause nail infections. The formulation demonstrated inhibitory activity against the organism, suggesting potential antifungal effects.
To assess the preliminary safety profile of Formulation F7, a clinical skin-irritation study was conducted in 12 healthy human volunteers under the supervision of a dermatologist. The participants were monitored for signs of localized skin irritation, erythema (redness), and inflammation.
The study reported no adverse reactions or severe redness among the volunteers, providing preliminary evidence of local tolerability. However, a small study in healthy volunteers cannot by itself establish the safety or effectiveness of the formulation for people with onychomycosis.
The researchers therefore noted that further studies are required before the effectiveness and safety of the herbal nail polish as a treatment for onychomycosis can be established.
Future research should examine how the formulation behaves under different storage conditions, determine the appropriate dose and application frequency, assess its safety during long-term use, and evaluate recurrence rates following treatment.
They also suggested investigating advanced nail-penetration technologies as possible ways to improve the movement of active compounds through the nail plate.
The study adds to growing research interest in plant-derived topical formulations for fungal infections, particularly in situations where prolonged treatment and effective delivery of medicines through the nail present significant challenges.