tavaborole and Hand-Dermatoses

Onychomycosis is a fungal infection of the fingernails and toenails that results in thickening, discoloration, splitting of the nails and lifting of the nail from the nail bed. The disease is caused by dermatophytes and has a high incidence within the general population, especially among older individuals. Present treatment options include both oral and topical drugs, with oral therapies giving better outcomes; however, neither of these treatment options provides high cure rates that are durable. The difficulty in treating onychomycosis results from the deep-seated nature of the infection within the nail unit (nail plate, nail bed and surrounding tissue) and the inability of drugs to effectively reach all sites. Ongoing drug development activities have focused on novel delivery technologies to facilitate penetration of existing antifungal drugs through the nail plate and on the discovery of inherently penetrable antifungals. AN-2690 represents an oxaborole antifungal that is designed to penetrate the nail plate and is showing promising results in clinical trials.

Topics: Administration, Topical; Animals; Antifungal Agents; Boron Compounds; Bridged Bicyclo Compounds, Heterocyclic; Foot Dermatoses; Hand Dermatoses; Humans; Onychomycosis

Topics: Antifungal Agents; Boron Compounds; Bridged Bicyclo Compounds, Heterocyclic; Ciclopirox; Debridement; Foot Dermatoses; Hand Dermatoses; Humans; Laser Therapy; Morpholines; Naphthalenes; Onychomycosis; Pyridones; Terbinafine; Triazoles

Onychomycosis is a challenging fungal infection to treat topically, likely due to the unique properties of the nail plate. This seemingly impenetrable barrier has high resistance to the passage of antifungal drugs in sufficient concentrations to kill the causative fungi deep in the nail bed. Recently, a new class of antifungal agent was described, termed oxaboroles, which have broad-spectrum activity. These oxaboroles were designed with properties believed to be required to allow for easier transit through the nail plate. Herein, we report (i) the nail penetration results of four oxaboroles that led to the selection of AN2690, (ii) the results of the nail penetration of AN2690 from four vehicles, and (iii) the nail penetration of AN2690 in its chosen vehicle compared to a commercial control, ciclopirox. AN2690 has superior penetration compared to ciclopirox, and achieves levels within and under the nail plate that suggest it has the potential to be an effective topical treatment for onychomycosis.

Topics: Antifungal Agents; Boron Compounds; Bridged Bicyclo Compounds, Heterocyclic; Chemistry, Pharmaceutical; Ciclopirox; Diffusion; Diffusion Chambers, Culture; Drug Compounding; Ethanol; Hand Dermatoses; Humans; Molecular Structure; Nails; Onychomycosis; Permeability; Pharmaceutical Vehicles; Pilot Projects; Propylene Glycol; Pyridones; Solubility; Time Factors