Figure 1.

Historical development of patches. Early topical products: (A) products from ancient times; (B) Galen's cold cream; (C) mercurial ointment; (D) mustard and belladonna plasters; controlled dosing of topical products. (E) First quantitative systemic delivery (Zondek's system). (F) Individualized delivery system: nitroglycerin ointment. (G) Topical delivery device (Wurster & Kramer's system). Passive non-invasive patches. (H) First patch system – the reservoir – introduced for scopolamine, nitroglycerin, clonidine and oestradiol. (I, J, K) Other types of patches – matrix and drug-in-adhesive (e.g. fentanyl and nicotine patches). Next-generation patches. (L) Cutaneous solutions (e.g. Patchless Patch®, Evamist®). (M) Active patches (e.g. iontophoresis, Zecuity®). (N) Minimally invasive patches (e.g. microneedles, Nanopatch®).