Table 1. Methodology of systematic review elaboration.

Steps	Answers
Question Formulation (Hypothesis)	How is the scenario of patent technologies involving nanotechnology-based delivery systems as skin penetration enhancers?
Study Location	International patents
Data Collection	Patent database: Espacenet (EPO) (Accessed on July 25th, 2019) Scientific articles database: Web of Knowledge (Accessed on August 8th, 2019) Strategies of search: 1) Keyword in the title: skin     Keywords in abstract: promot* or enhanc* and penetrat* or absorp* or permeat*     No time restriction 2) Keyword in the title: skin     Keywords in abstract: promot* or enhanc* and penetrat* or absorp* or permeat* and nano*     No time restriction 3) Keyword in the title: skin     Keywords in abstract: promot* or enhanc* and penetrat* or absorp* or permeat* and nano*     Period: 2008 - 2018
Critical Evaluation of Studies	Tabulation of patents of the third search strategy. Accounting by technology and not by patents (avoid repeated counting). Exclusion of patent technologies that do not fit the article purpose. Division of patent technologies by categories (year, country, type of applicants, types of products, types of nanostructure).
Data Analysis and Presentation	Graphs and tables elaboration. Discussion of results trying to understand the data obtained, and comparison with scenarios from other sources (scientific papers).
Review Enhancement	Search perspective every 5 years.