Drug delivery encompasses the methods, manufacturing processes, technologies, formulations and storage systems used to transport a pharmaceutical compound to its target site in order to produce the intended therapeutic effect. Its goal is to modify a drug's specificity and pharmacokinetics by formulating it with various medical devices, excipients and drug carriers. Drug delivery techniques that are frequently utilized include controlled, targeted and steady drug delivery. Since the introduction of systems of medical applications, a variety of drugs are being used to treat a number of diseases through the administration of various conventional forms of drug delivery, including lotions, ointments, suppositories, solutions, pills, mixtures, pastes, powders, tablets, etc. The three main mechanisms of drug delivery are swelling, diffusion and erosion. This book aims to understand the evaluation, formulation and mechanisms of drug delivery. It covers in detail some existent theories and innovative concepts revolving around this domain. Those with an interest in this field of study would find this book helpful.