Non-Compartmental and Compartmental Approaches to Pharmacokinetic Data Analysis

The evaluation of pharmacokinetic parameters is an essential part of understanding how drugs function in the body. To estimate these parameters, studies are undertaken in which time-dependent measurements are collected. These studies can be conducted in animals at the preclinical level, through all stages of clinical trials, and can be data rich or sparse. No matter what the situation, there must be some common means by which to communicate the experimental results and summarize key features of a drug’s properties. Pharmacokinetic parameters serve this purpose. Thus, in the field of pharmacokinetics, the definitions and formulas for the parameters must be agreed upon, and the methods used to calculate them understood. This understanding includes assumptions and domains of validity, for the utility of the parameter values depends upon them. This chapter examines the assumptions and domains of validity for the two commonly used methods of pharmacokinetic modeling analysis – non-compartmental and compartmental. Compartmental models have been presented in earlier chapters. This chapter will expand upon this, and compare the two methods.