A topical sustained release delivery system for delivery of antifungal agents to the finger or toenails achieving high penetration through the nails by combining the antifungal agent with a keratolytic agent and a humectant. The pharmaceutical sustained release topical preparation is provided in a varnish or spray form for treating the nail and surrounding tissues, where the active ingredient is an antifungal agent, a keratolytic agent, or preferably a combination of an antifungal and a keratolytic agent. The composition may further comprise an antibacterial, an antiviral, an antipsoriatic agents, or combinations thereof.