This book provides concepts, procedures, guidelines, and regulatory affairs in drug development. Pharmaceutical Regulatory Affairs: Principles and Practices begins with a detailed overview of the drug development life cycle, from initial discovery and preclinical research to clinical trials and market approval, addressing scientific, regulatory, and ethical considerations at each stage. The book covers the evolution of global trade agreements like the General Agreement on Tariff and Trades (GATT) and the World Trade Organization’s (WTO) impact on pharmaceuticals, highlighting issues surrounding pharmaceutical patents and intellectual property rights. It discusses the importance of the Scale-Up and Post-Approval Changes (SUPAC) guidelines in ensuring quality and consistency in drug manufacturing post-approval and examines the World Health Organization's (WHO) guidelines on technology development and transfer. The fundamentals of regulatory affairs are covered, emphasizing the roles and responsibilities of regulatory professionals. The book provides an in-depth look at regulatory frameworks of major agencies worldwide, including the Central Drugs Standard Control Organization (CDSCO) in India, the Food and Drug Administration (FDA) in the US, the European Medicines Agency (EMA) in the EU, the Therapeutic Goods Administration (TGA) in Australia, the Pharmaceuticals and Medical Devices Agency (PMDA) in Japan, Health Canada, and regulatory authorities in emerging markets. It also addresses the international regulatory landscape for medical devices and reviews foundational pharmaceutical regulations. Additionally, the text explores regulatory guidelines for clinical testing, including the roles and responsibilities under pharmaceutical legislation, principles of bioethics and biosafety, the digital transformation in clinical trials, and the critical role of pharmacovigilance. The book concludes with an examination of the global regulatory scenario for pharmaceutical excipients, providing a detailed roadmap through the complexities of drug development, regulatory compliance, and global standards. This book is valuable for professionals, researchers, and students of pharmaceutical sciences.