Pharma Easy Notes @Pharmacy

All the chemical substances that are not nutrients, which enter the body through i ngestion i nhalation or a bsorption is called xenobiotics or exogenous compounds. Drugs are also xenobiotics under their lipophilicity. Water-soluble agents undergo renal excretion whereas lipid-soluble substances are passively reabsorbed from the renal tubule into the blood after glomerular filtration. This enzymatic biotransformation is known as drug metabolism. " Drug biotransformation is thus a detoxification process. a) Sites of Bio-transformation The Principle site of drug metabolism is not only the liver but also the kidney, lungs , and GI tract are also important sites. When a drug is taken orally, it is usually absorbed through a mucous membrane of the small intestine or from the stomach. Once out of GI tract it is carried by the bloodstream to the liver, where it is usually first metabolized. Metabol

Introduction The biological activity of a targeted drug molecule is solely dependent on its physicochemical characteristic essentially (NTS) N ature & T ypes of functional moieties and also the S patial arrangement of such group in the molecule [Note: Spatial arrangement of atoms concern how different atomic particles and molecules are situated about in the space around the organic compound namely its carbon chain, each with their unique placement of atoms in 3-dimensional space] Following introduction in the body The drug must pass through many barriers before it reaches the site of action usually a receptor or cell. How the drug is T ransported D istributed throughout the body compartment M etabolic alteration E xcretion Physiochemic