Pharmacokinetic PK study help researchers examine absorption, distribution, metabolism, and excretion properties of a drug product. On the other hand, pharmacodynamics (PD) studies the effect of a drug product on the body. Both PK and PD properties of drugs are crucial for designing subsequent clinical trials. Besides, PK/PD simulation helps researchers identify safe doses for first-in-human studies.
PK bioanalysis is crucial for analyzing safety and efficacy data obtained from clinical studies and post-marketing analysis. Moreover, sponsors must always compare preclinical and clinical toxicology data with PK drug data to better guide the conduct of studies in human participants. Hence PK assays are crucial for all aspects of drug development projects. The current article highlights critical steps pharmaceutical services must consider when creating a pharmacokinetic study design.
Steps for a robust pharmacokinetic study design
Pharmacokinetic assays must measure analyte concentrations with precision, accuracy, and specificity. While validating PK samples, sponsors must conduct stability studies through the entire lifecycle. Besides, assays should follow GLP practices. Generally, the researchers must follow the same PK study design throughout the drug development process. However, this may not be possible with every project, and researchers may require newer methods. In such cases, sponsors must perform cross-validation and clarify the relationship between assays.
Generally, the final formulation is not used to generate PK data during early drug development. This deviation is acceptable. However, PK data for the final formulation is mandatory before submitting data for NDA.
Sponsors must use healthy subjects for obtaining PK drug data. Besides, studies must be adequately designed for accurate and reliable PK data. Researchers must also focus on individual variation and accordingly enroll an appropriate number of participants in the study. Not to mention, the effects of frequent blood collection must be considered in the PK study design.
PK studies must be designed in such a way that participants showing different PK properties must also be considered for analysis. These subjects will include the elderly and children population, individuals with renal or hepatic disorders, and participants with decreased drug activity. If possible, intravenous administration should also be studied for drugs that are not to be administered intravenously. Besides, when significant drug interactions are identified through nonclinical studies, researchers must ensure that clinical PK studies include associated drug interaction analysis.
In early drug development studies, PK analysis must include an appropriate number of healthy individuals. However, in the case of high-risk drugs, sponsors must enroll the target patient population for PK analysis. For the late stages of drug development, patients with the target diseases must be enrolled in PK studies. Ideally, the correlation between dosage and blood drug concentration and drug concentration and therapeutic effects is desirable.
Finally, it is necessary to determine the type of pharmacokinetic study to be used for analysis in advance. Standard PK study and population PK study are two primary ways to assess the PK properties of a drug product. Standard PK studies employ single and repeated dose studies to evaluate the PK properties of the drug. Whereas population PK study uses blood concentration drug data from clinical trials to assess the safety and efficacy profile of the drug.