In current drug discovery and development field bioanalytical techniques plays an important role in quantitative determination in plasma. Various pharmacokinetics, toxicokinetics, bioequivalence and exposure-response (pharmacokinetics/ pharmacodynamics) are biomedical drug development pursuits that cannot be accomplished without an accurate means of quantifying the moieties that scientists seek to characterize. Many chromatographic techniques immensely used for this. Hence this book comprehensively gives an overview on various important aspects and challenges in bioanalytical techniques. Beside this it also enlighten bioanalytical method validation which gives regulatory requirement for any process.