Pharmacokinetics is the study of drug delivery through absorption/dispersion into the body, distribution around the body and elimination or excretion out of the body. Drug delivery into a body depends on numerous factors. These include:
A) The drug and its properties this includes: absorption/diff usion rate, formulation, life time.
B) Drug effectiveness, local and/or systemic e ffect requirements
C) Patient needs which includes convenience of method (oral vs intravenous), clinical condition.
D) Risk involved.