Pharmacology is the scientific study of the effects of drugs and chemicals on living organisms where a drug can be broadly defined as any chemical substance, natural or synthetic, which affects a biological system. Pharmacology may involve how organisms handle drugs, identification and validation of new targets for drug action, and the design and development of new drugs to prevent, treat and cure disease. Pharmacology research is also a critical component in the development of modern 'personalized medicine'

Pharmaceutical chemistry deals with the discovery, desin, development and both pharmacological and analytical characterisation of drug substances. Medicinal chemists are indispensible in the preclinical stages of drug development, and again as pharmaceutical chemists in drug quality control. The chapter describes stages of drug development (hit to lead to preclinical candidate to drug substance), followed by a summary of the phases of drug activity relating to a drug#s formulation, pharmacokinetics and pharmacodynamics. Finally, classification systems for marketed drug substances are presented, with an emphasis on the classification by molecular target.

The primary mission of the pharmacy profession is to have a positive impact on the provision of public health service by ensuring the safe and effective use of medications. There are various facets to this mission, including the preparation and distribution of medications, as well as contact with patients and other members of the healthcare team.

Pharmacognosy is “to acquire knowledge of drugs.” In the past, most of the drugs were derived from herbs and conventional pharmacognostical studies were focused on the systematic study of medicinal plants and medicines derived from plants. However, the interests and scope of Pharmacognosy were gradually expanded by incorporating applied domains of botany, chemistry, biology and pharmaceutical science.

Pharmaceutical Analysis is a branch of practical chemistry that involves a series of process for identification, determination, quantification and purification of a substance, separation of the components of a solution or mixture, or determination of structure of chemical compounds.