What is a Pharmacokinetic (PK) Study?

Pharmacokinetic Study provides the basis for identifying drug distribution, absorption, metabolism, and excretion.


Absorption, the first part of PK studies, is the process by which drugs enter into the blood circulation. Drug substances can enter the body through several channels such as gastrointestinal tract, nasally, dermally, or parenterally. Absorption at the gastrointestinal tract, one of the most common drug absorption sites, is affected by several factors such as physicochemical parameters of the drug, gastrointestinal motility, and drug concentration at the site of absorption.


Distribution is a reversible transfer of drug within the body from one location to another. The distribution of a drug can be influenced by several factors such as lipid-solubility, concentration in plasma and various tissues, and protein binding of drugs in plasma. PK studies help capture this crucial information.


Metabolism, an essential part of PK analysis, is the process by which a drug is converted to other chemical entity (metabolite). Metabolism happens primarily in the liver and usually occurs in two stages: Phase I reactions in microsomes are catalyzed by a group of enzymes known as the cytochrome P450 system that plays a significant role in drug metabolism. The typical chemical reactions involved in Phase I are aromatic hydroxylation, aliphatic hydroxylation, oxidative N dealkylation, oxidative O-dealkylation, S-oxidation, reduction, and hydrolysis. Most often this simple functionalization could be sufficient to make a drug more soluble, facilitating elimination through the kidneys. In Phase II metabolism, conjugation occurs by glucuronidation, sulfation, amino acid conjugation, acetylation, methylation or glutathione conjugation to aid elimination. Several factors influence drug metabolism including the route of administration, dose, genetics, disease state, and metabolic activity.


Eliminating the drug and other toxic substances from the body, the last part of the PK study, is known as the process of excretion. Majority of the drugs in the body are eliminated through the urine. Excretion also depends on the solubility of the drug in water. More soluble drugs are excreted faster in urine. If the excretion is incomplete, the accumulation of compounds in the body can hurt metabolism.

PK Analysis during Drug Discovery, Preclinical, and Clinical Phases

PK analysis carried throughout the drug research and development process starting from early discovery to the last Phase of drug development. The primary purpose of pre-clinical pharmacokinetic studies is to evaluate the characteristics of the drug to predict human kinetics. PK Assays during the preclinical phase help determine bioavailability, the volume of distribution, half-life, and clearance. These PK studies help evaluate if the drug has adequate success potential or needs to be modified to improve its pharmacokinetic parameters. PK study results from the preclinical stage help design IND enabling Tox studies in animals and based on these preclinical results drugs can be advanced farther into clinical development.

Which PK Assay does NorthEast BioLab Offer?

We offer a wide range of PK Assay beginning from the early discovery phase when a potential drug (NCE) is administered to rodents for understanding ADME properties. Once an NCE is found suitable for further development, we also provide PK assay for dose range finding studies followed by IND enabling Tox studies in rodent and non-rodent animals. PK studies in animals are critical for advancing the drug into clinical development. Furthermore, we provide clinical pharmacokinetics during clinical trials by developing and validating bioanalytical methods in the human plasma post the FDA approval of your IND application.

Why Choose Northeast BioLab for your Pharmacokinetics (PK) Study?

Pharmacokinetics studies, such as ADME and toxicokinetic demand both in-depth expertise and nimble execution. NorthEast BioLab is the right partner to assist you in bringing new, effective drugs to the market given the critical and detail-orientated nature of these PK studies in pharmaceutical drug development.

Our team of veteran scientists can help discern your top drug compound based on our15+ years of experience in method development, validation, transfer for PK analysis and related assay. Together, we would develop robust bioanalytical methods to support your PK studies for the analysis of drugs and metabolites in biological fluids. We promise a high quality and take full responsibility for all your projects, including compliance with various regulations mandated by authorities and agencies such as FDA and ICH.