Theoretical and Experimental Aspects of Biopharmaceutics and Pharmacokinetics

 Drug research is a unique multi-disciplinary process heading towards the development of novel therapeutic agents in areas of currently unmet medical need. Drug research can be divided functionally into discovery, design and development. The key objective of drug development is the generation of a scientific database that supports the effectiveness and safety profile of the dosage regimen(s). Majority of the drug molecules fail in subsequent drug development programs because the efficacy and safety are not governed by its Pharmacodynamic characteristics alone. It also depends to a large degree on the biopharmaceutical (e.g. solubility, stability, permeability and first pass effect) and pharmacokinetic (clearance rate, biological half-life, extent of protein binding and volume of distribution) properties of the drug, since these properties control the rate and the extent to which the drug can reach its site of action, i.e. biophase. Poor pharmacokinetics was solely responsible for nearly 90% terminations of drugs. Hence, understanding of these properties is essential to all scientists involved in drug discovery and development. Biopharmaceutics is a major branch of the pharmaceutical sciences concerned with the relationship between the physicochemical properties of a drug in dosage form and the pharmacologic, toxicologic, or clinical response observed after its administration. Pharmacokinetics serves as a useful tool in the drug development process, both in terms of therapeutics and in defining drug disposition characteristics. Biopharmaceutics and pharmacokinetics are the most important parts of pharmaceutical sciences because they bridge the gap between the basic sciences and the clinical application of drugs