RxNav 2.0 – A web-based mobile-responsive RxNorm browser Lee Peters and Olivier Bodenreider National Library of Medicine, Bethesda, Maryland, USA RxNav is a browser for several drug information sources, including RxNorm, RxTerms and NDF-RT. Since its release in 2004, many features have been added, but the Java Web Start framework was unchanged. In 2016, RxNav was redesigned to conform to modern web application principles, with the goal of simplifying the user experience and supporting mobile devices. Motivation Figure 1. RxNav 2.0 on a mobile phone. Figure 2. New simple graph view. More convenient and faster. RxNav 2.0 is a web application accessible from the RxNav website and only requires a browser such as Chrome or Firefox, whereas the original version of RxNav required users to install Java on their system to run the application. RxNav 2.0 has a faster startup time, as well as faster search times. Designed for mobile devices. Based on responsive design techniques, RxNav 2.0 can be displayed on workstations, tablets and mobile devices, whereas the original application required a large display area. Figure 1 shows a screenshot of RxNav 2.0 on a mobile phone. Additional features. The functionality of the original application is preserved and some new features added. In addition to a simplified alternative to the RxNorm graph (Figure 2), these new features include: Ubiquitous searching. Searching can be done while visiting any tab in RxNav 2.0. NDC properties and history. The NDC tab displays properties from DailyMed for each NDC and contains a history feature that displays all past and present NDCs for the RxNorm concept. Links to RxClass. The nodes in the graphs in the Class View tab are linked to RxClass, so that selecting a class node in RxNav 2.0 opens a window in RxClass for that class. Status tab. The status tab contains concept status and history returned from the RxcuiHistory API introduced in 2017. Search history. A search history allows the user to conveniently revisit previous searches. Features of RxNav 2.0 For more information about NLM drug information services: https://rxnav.nlm.nih.gov/ Acknowledgments: This work was supported by the Intramural Research Program of the NIH, National Library of Medicine.