Nanoparticles for dermal and transdermal drug delivery

摘要: The term “nanoscale” refers to particle size range from~ 1 to 100 nm [1], but for the purpose of drug delivery, nanoparticles in the range of 50–500 nm are acceptable depending on the route of administration. The method by which a drug is delivered can have a significant effect on its efficacy. Some drugs have an optimum concentration range within which maximum benefit is derived and concentrations above or below this range can be toxic or produce no therapeutic benefit. The slow progress in the efficacy of the treatment of several diseases has suggested a growing need for a multidisciplinary approach to the delivery of therapeutics to target tissues [2]. Transdermal drug delivery systems (TDDS) or patches are controlled-release devices that contain the drug either for localized treatment of tissues underlying the skin or for systemic therapy after topical application to the skin surface [3]. TDDS are available for a number of drugs, although the formulation matrices of these delivery systems differ. They differ from conventional topical formulations in the following ways:• they have an impermeable occlusive backing film that prevents intensive water loss from the skin beneath the patch;• the formulation matrix of the patch maintains the drug concentration gradient within the device after application so that drug delivery to the interface between the patch and the skin is sustained; and