Drugs play a vital role in the progress of the human civilization. The word "drug" has been derived from the French word "Drogue", which means a dry herb. It is defined as any substance or product that is used or intended to be used to modify or explore physiological systems or pathological states for the benefit of the recipient. A large number of bio-active compounds are available in the form of pharmaceutical formulations to control diseases. The discovery of many new drugs has helped in the successful eradication of many deadly diseases. The advances in the fields of chemistry and other branch of chemo-metrics have made it possible to design the new drugs of maximum therapeutic effect and minimum side effects. In the recent years, more and more synthetic organic and inorganic compounds are used for the treatment of diseases.