Six-month open-label clinical study of a novel topical solution for mild distal lateral subungual onychomycosis

Systemic antifungals such as terbinafine and itraconazole are often limited by drug interactions and side effects in the treatment of onychomycosis. We tested a new topical solution to address the clinical need for safer and more effective topical therapies. The solution (containing urea, lactic acid, ethoxydiglycol, decylene glycol, and polyquaternium-7) was applied twice daily for six months in a single-arm, open-label trial, enrolling 50 adult subjects with clinically diagnosed distal lateral subungual onychomycosis. Outcomes included a blinded investigator assessment, mycological evaluation (KOH microscopy and culture), and patient self-assessment of efficacy and usability. Nail growth (mm) was monitored. Complete cure was defined as negative mycological results and resolution of clinical signs. Adverse events were assessed for safety. Forty patients completed the study. At three months, 32/40 of participants (80%) achieved negative mycological results; blinded assessments at this time showed moderate improvement in 24/40 (60%) and excellent improvement in 12/40 (30%) of patients. At six months, the complete cure rate was 50%, (20/40), and 42.5% (17/40) showed significant clinical improvement. Investigators rated the treatment positively in 90.0% (36/40) of cases. Four patients developed mild periungual erythema due to improper application, which spontaneously resolved without discontinuation. This topical "barrier-effect" treatment was associated with improvements in nail appearance and fungal resolution after only 12 weeks, with further benefit at six months, and was safe, well tolerated, and easy to use. Also, concomitant use with systemic antifungals may be possible subject to further studies.