Pharmacological Experiments And The Discovery Of New Drug

PHARMACOLOGICAL EXPERIMENTS: 

Pharmacological experiments have played a crucial role in discovering and developing new drugs that have revolutionized the field of medicine. These experiments involve the testing of various substances on biological systems to evaluate their safety, efficacy, and potential therapeutic benefits. Discovering a new drug is complex and requires extensive research, testing, and regulatory approval. There is no standard formula. There are different approaches to discovering new drugs. Most of the new drugs are identified through one of the following approaches:

APPROACH 1:

Chemical modification of already known molecules e.g. development of thiazide diuretics from much less useful carbonic anhydrase inhibitors. It is also called the structure-activity relationship. By using this method the efficacy of chemicals may be increased by adding or removing the functional group. Another example is Captopril which is modified to Enalapril.

APPROACH 2:

The random screening for the biological activity of natural products and previously discovered chemical entities e.g. the discovery of cyclosporine. It is an important immunosuppressant agent.

APPROACH 3:

Rational drug designing based on biological mechanism and chemical structure of compound (computer-aided drug design). Hypothetical structures are developed with computer assistance, and then the scientist develops different drugs following information from a computer, based on their knowledge on receptors to which the drug will bind. For example, the development of H2 receptor antagonist.

APPROACH 4:

The experimental approach of folk remedies. It is based on potential use in remedies rather than scientific proofs. E.g. the use of honey, Kalongi (kaladana), Ajwain. Willow bark was used for its analgesic, antipyretic & anti-inflammatory effect for two centuries without having its mechanism of action known until Aspirin was discovered in 1970.

 APPROACH 5:

Serendipity: the drug discovered by chance or accidentally e.g. penicillin.

APPROACH 6:

Systematic approach: It is the use of a rational program from concept to finished products. It means that the chemist stands with more than 200 chemicals. These chemicals then pass through different pharmacological tests. Many of these chemicals are found useless and are rejected and finally only a few chemicals have pharmacological activities that are further developed into useful drugs.