Advance development and current challenges in nails drug delivery-A review

Abstract

Nails drug delivery system (NDDS) is an important delivery system in mammals, in which their nails are highly affected by the fungal diseases. Disorders of the nail unit range from relatively innocuous conditions such as pigmentation in heavy smokers, to painful and debilitating states where the nail unit can be dystrophied, hypertrophied, inflamed, infected etc. The human nail forms a resistant barrier to the topical penetration of drugs. Thus, treatment of nail disorders, such as fungal infections, remains a challenge because of the difficulty encountered in achieving therapeutic concentrations of drugs at the site of infection, which is often under the nail. Ungual and trans-ungual drug delivery continues to receive significant attention due to the need for efficacious topical therapies for onychomycosis given the potential risk of systemic adverse effects associated with the conventional oral therapy. To successfully treat nail disorders, applied drugs must permeate through the dense keratinized nail plate and reach the deeper layers of the nail plate, nail bed and the nail matrix. Physical, chemical and mechanical methods have been used to decrease the nail barrier. This current review include anatomy of human nail, nails disorders, factors affecting tans-ungual delivery of drugs and methods used for enhancement of drugs penetration into/across the nail.