volume of distribution
Volume of distribution (Vd or VD) defines the distribution of a drug between the blood plasma and other bodily tissues after oral or parenteral administration. VD can be considered as the size of the compartment in to which the drug distributes following absorption. It is the theoretical volume that would be necessary to contain the total amount of an administered drug at the same concentration that it is observed in the blood plasma. The higher the VD, the greater the degree of drug distribution in to the tissues.