Editing Route of administration (section)

===Local===
By delivering drugs almost directly to the site of action, the risk of systemic [[adverse effect|side effects]] is reduced.<ref name="Nursing Times"/>

Skin absorption (dermal absorption), for example, is to directly deliver drug to the skin and, hopefully, to the systemic circulation.<ref name="Rodrigues Oliveira 2016 pp. 155–167">{{cite book | last1=Rodrigues | first1=Francisca | last2=Oliveira | first2=Maria Beatriz P.P. | title=Concepts and Models for Drug Permeability Studies | chapter=Cell-based in vitro models for dermal permeability studies | publisher=Elsevier | year=2016 | isbn=978-0-08-100094-6 | doi=10.1016/b978-0-08-100094-6.00010-9 | pages=155–167}}</ref> However, skin irritation may result, and for some forms such as creams or lotions, the dosage is difficult to control.<ref name=DDS/> Upon contact with the skin, the drug penetrates into the dead [[stratum corneum]] and can afterwards reach the viable [[epidermis]], the [[dermis]], and the [[blood vessel]]s.<ref name="Rodrigues Oliveira 2016 pp. 155–167"/>