Process of drug discovery

 Discovery

Discovery is the identification of novel active compounds, often called "hits", which are typically found by screening many compounds (compound library) for the desired biological properties. While a number of approaches toward the identification of hits exist, the most successful of techniques relies on chemical and biological intuition developed through years of rigorous chemical-biological training. Other sources of hits can come from natural sources, such as plants, animals, or fungi. Hits may originate also from synthetic chemical libraries, such as those created through combinatorial chemistry or historic chemical compound collections that are tested en-masse against the biological target in question.
Optimization

Another step in drug discovery involves further chemical modifications in order to improve the biological and physiochemical properties of a given candidate compound library. Chemical modifications can improve the recognition and binding geometries (pharmacophores) of the candidate compounds, their affinities and pharmacokinetics, or indeed their reactivity and stability toward metabolic degradation. A number of methods have contributed to quantitative metabolic prediction, and a recent example is SPORCalc[1].The quantitative structure-activity relationship (QSAR) of the pharmacophore play an important part in finding lead compounds, which exhibit the most potency, most selectivity, best pharmacokinetics and least toxicity. QSAR involves mainly physical chemistry and molecular docking tools (CoMFA and CoMSIA), that leads to tabulated data and first and second order equations. There are many theories, the most relevant being Hansch's analysis that involves Hammett electronic parameters, steric parameters and logP(lipophilicity) parameters.
Development

The final step involves the rendering the lead compounds suitable for use in clinical trials. This involves the optimization of the synthetic route for bulk production, and the preparation of a suitable drug formulation.