The High performance liquid chromatography is basically a highly improved form of column chromatography used for estimation of pharmaceutical drugs in blood plasma, pharmaceutical preparations and used in food analysis etc., . UV-Visible Spectroscopy methods are simple, sensitive, precised and cost effective. In this book these techniques are adopted to estimate the drugs. Few heterocyclic drugs selected based on literature, new analytical methods were developed and validated as per ICH Guidelines

Quinazoline is the main six-membered heterocyclic ring system reported for their biological activities, compounds with multiple pharmacophores, which bring together knowledge of a target with understanding of the molecule types that might interact with the target family. Robust, versatile and scalable chemistry must be employed to accomplish the task. This characteristic feature of quinazoline would make a good template for a lead generation library. The current review article focuses on biological actions done for various targets along with the brief description of the targets.