Pharmacology is a branch of drugs and pharmaceutical sciences which is involved with the examine of drug or medication action,in which a drug may be widely or narrowly described as any man-made, natural, or endogenous (from inside the body) molecule which exerts a biochemical or physiological impact on the cell, tissue, organ, or organism (on occasion the phrase pharmacon is used as a term to encompass these endogenous and exogenous bioactive species). More especially, it's miles the examine of the interactions that occur among a residing organism and chemicals that affect normal or abnormal biochemical function. If substances have medicinal homes, they may be taken into consideration prescribed drugs. The discipline encompasses drug composition and residences, synthesis and drug design, molecular and cell mechanisms, organ/systems mechanisms, sign transduction/cell conversation, molecular diagnostics, interactions, chemical biology, therapy, and clinical programs and antipathogenic talents. The two essential areas of pharmacology are pharmacodynamics and pharmacokinetics. Pharmacodynamics studies the consequences of a drug on organic structures, and pharmacokinetics studies the consequences of organic structures on a drug. In huge terms, pharmacodynamics discusses the chemicals with biological receptors, and pharmacokinetics discusses the absorption, distribution, metabolism, and excretion (ADME) of chemicals from the organic structures