Each new pharmaceutical compound needs to undergo sets of tests to determine its course and effects on the human body. A pharmacokinetic study gives the researchers a mathematical understanding of the time course of the compound in vivo.
What is the purpose of a PK study?
Commonly, a pharmacokinetic study quantifies the following processes – Absorption, Distribution, Metabolism, and Excretion. The process is referred to as ADME, and it determines the concentration and bioavailability of a particular compound inside the body. It is imperative for the drug designing process and the determination of a drug regimen for an individual.
What are the standard guidelines for a PK study design?
Before a drug becomes available to the general population at pharmacies and clinics, the compound needs to undergo rigorous PK clinical trials. These studies include the assessment of the formulation effect, which is distinct from any other impact. For example, the PK assay of two compounds should include a two-sequence crossover and two-period study.
The research team should include a washout period between the two assays to avoid any interaction between the two compounds. The design of the PK assay can vary depending on the half-life of the compounds. Alternative parallel designs are ideal for moieties with long half-lives inside the human system.
Why is standardization important for the pharmacokinetics study of drugs?
A PK clinical trial requires a significant number of subjects. The study population needs to be statistically significant. Relying on a large number of subjects allows subsequent removals or withdrawals from the study. At the same time, larger populations enable the researchers to observe all possible interactions and actions of the compound.
While choosing candidates for a PK clinical trial, the team should aim to minimize the variability within subjects. The subjects should include healthy adult volunteers. The study subjects can be male or female, depending on the safety and usage criteria of the drug in question.
Will the choice of bioanalytical methods influence a PK study?
A PK assay often includes mass spectrometric studies due to the requirement of high sensitivity for the observation of compound concentrations at a low dose or variation in concentration through a prolonged duration. Your choice of bioanalytical methods will determine the sensitivity and accuracy of the trials. The results will determine the future of a particular medicinal compound.
What is a pharmacokinetic analysis?
An integral part of the study of a new drug is pharmacokinetic analysis. PK testing involves noncompartmental and compartmental methods. The non-compartmental techniques allow the approximation of the exposure to the drug by measuring the area under the concentration-time curve. At the same time, the compartmental methods leverage kinetic models to estimate the concentration-time graph.
It helps in the estimation of the bioavailability of a drug, its interaction with enzymes, and the prediction of drug interactions. It can also provide actionable data on therapeutic drug monitoring (TDM). Obtaining the results of human PK analysis of parent drugs is a must for ensuring the appropriate use of medicines.