%0 Journal Article %T TOXICOKINETICS: AN IMPORTANT TOOL IN NEW DRUG DEVELOPMENT %A Dheeraj Gopu %J International Journal of Pharmacy and Biological Sciences %D 2011 %I International Journal of Pharmacy and Biological Sciences %X Toxicokinetics (TK) is generation of kinetic data for systemic exposure and toxicity assessment of the drug. These studies help us to estimate the observed toxicity to that dose. TK evaluation is very important in drug development phase in both regulatory and scientific perspective. There are several guidelines to conduct TK study in animals recommended by regulatory bodies (OECD). TK evaluation is useful in selection of dose, dosing form, alternative dosing route, evaluation of toxicological mechanism, and also used for the setting safe dose level in clinical phases. This TK studies also used to reduces the animal number (replacement, reduction and refinement). On the other hand, TK data are practically used for the purpose of drug discovery such as lead-optimization and candidate-selection. This review discussed about the principles involved in TK studies, application and importance in drug development stages and approaches to reduction the number of animals in the study. %K Toxicokinetics (TK) %K drug development lead-optimization %K OECD %U http://www.ijpbs.com/data/JULY-SEPT%202011/319-327.pdf