Drug Designing, Discovery and Development Techniques

Abstract

Human body is a complex chemical machinery, with as many as thousands of chemicals, namely proteins, carbohydrates, fats, etc. which exist all together. Every process in the body is some sort of chemical conversion that leads to movements, thought processes, feelings, pain and many more such complex as well as simple processes. The human body has also been provided with all the necessary chemical components or precursors, various enzymes and neurotransmitters for the balanced and proper functioning of all the life sustaining processes. Yet it so happens that some machineries or bioprocesses fail to function due to several exogenous or endogenous factors. Hence providing external aids, which we call “Drugs” or “Medicines”, becomes essential to restore the normal functioning. Drugs are nothing but chemical entities of synthetic or natural origin, which only modulate the body functions and have no new action on the body. This explanation however does not fit the chemotherapeutic agents used to treat parasitic infections, as they have no action on the human body, but, are targeted to the invading organism (Richard et al., 2009). The exogenous factors are varied right from parasitic invasion to some chemical entities which tend to disrupt the normal bodily functions. Hence repairing becomes mandatory, if bodily repair mechanism cannot match the rate of damage. The endogenous factor maybe faulty, functioning of organs, any genetic or congenital factor, over or under-production of some precursors which may lead to disorders. The classical examples of disorders due to endogenous factors are the neurodegenerative disorders like Parkinsonism and Alzheimer’s disease which arise due to the imbalance of acetylcholine and dopamine in the central nervous systems. Though there is no cure for these disorders but drugs and therapies have been developed to prolong and improve the quality of life. (Moore et al., 2005; Cummings et al., 1998). Hence, drug discovery can also called as patient-oriented science meant for improving the quality of life by developing newer and safer agents.