Skin being the largest organ of the human body and because it offers specific advantages over other routes such as ease of access and bypassing the first pass metabolism, it presents a tremendous opportunity for administering drugs. Dosage forms meant to deliver drugs via skin can be broadly classified into topical and transdermal dosage forms. Topical dosage forms such as gels, creams, ointments, lotions are meant to be applied on skin for localized delivery of drugs to the affected areas. They differ from transdermal dosage forms, such as patches, in the fact that the drugs applied topically are less likely to be absorbed into the systemic circulation. Their site of action is either in one of the skin layers or in deeper tissues under the skin. The differences in composition and method of fabrication can be key aspects which dictate the site of delivery of drug from these dosage forms. The blood supply, however being present in the dermal layer of skin, can lead to some absorption of drugs to the systemic circulation even from topical dosage forms.