Redistribution refers to the change in the plasma drug concentration which is significant enough to cause alteration/termination of drug action. The alteration of plasma concentration occurs due to the second phase of drug distribution. The commonest example is the redistribution of thiopentone.
Movement of drug from plasma to specific tissue like brain is distribution and movement of drug from brain to plasma and from plasma to less perfused organs like adipose tissue and muscle is called as re-distribution.