This volume was completed from papers presented at the 4th International Conference and Exhibition on Pharmaceutical Sciences and Technology (PST), June 23 - 24, 2021, Bangkok, Thailand and the 2nd International Conference on Engineering Tribology and Applied Technology (ICETAT 20, 6-8 November 2020, Taiwan). The collection topics cover pharmaceutical materials development and research, including bioactive compounds, adjuvants, and nanoproducts as well as reflects the results of the last researches in the area of tribology, anti-friction, coatings, mechanical properties of structural materials, and surface engineering.