This book provides an in-depth educational review of Dimethyl Sulfoxide (DMSO) and its utility in pharmaceutical drug development with specific focus on topical, parenteral, and biologics applications and formulations. Dimethyl sulfoxide is a widely used but often under-appreciated pharmaceutical material, which is perceived to be primarily confined to discovery research. This book helps to change this perception. This book brings current awareness of this multifunctional material as an API and excipient. This book also summarizes the safety and toxicology of dimethyl sulfoxide as it compares to other aprotic solvents. The intended audience is pharmaceutical scientists, pharmaceutical formulators, researchers, drug development professionals and academics.