ABSTRACT
The skin offers a large and accessible surface for the drug delivery. Typically dosage forms applied to skin can be utilised to achieve either local action or systemic action of drugs. The “dermal drug delivery systems” deliver the drug molecules to the particular locations within the skin for their local action is known as topical drug delivery. Whereas, transdermal drug delivery systems (TDDS) deliver the drug molecules through the skin direct into the blood circulation for their systemic effects. Figure 3.1 represent the difference between topical and transdermal drug delivery.
