Today, pharmacokinetic studies are gaining momentum in the drug development domain. From early drug discovery studies to preclinical and clinical testing, pharmacokinetics studies have become integral for generating vital information at regular interviews. This drug development data is critical for making better go/no-go decisions based on sound scientific data.
The ultimate goal of pharmacokinetic studies is to predict and confirm the physical and chemical nature of drug compounds in a biological system. Today, to overcome multiple issues concerning in vivo testing, researchers are increasingly employing in vitro assessments using systems originating from human samples to overcome hurdles associated with in vivo testing. Similar to advanced biomedical assessments such as ddPCR gene expression analysis, PK ELISA assays require robust development and validation initiatives. The current article discusses the challenges and solutions for pharmacokinetic study design.
A comprehensive guide for pharmacokinetic labs
During the investigative stage, drug developers may face multiple issues resulting in the discontinuation of drug development programs. The primary issues at this stage are:
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Too low drug concentration or too short drug half-life
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Drug-drug interactions resulting in toxicity or reducing drug efficiency
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Highly variable drug reactions among patients causing difficulty in identifying and administering appropriate dosage
It is vital to consider these factors as early as possible while developing a new drug product. Importantly, drug developers should evaluate both metabolic and absorption properties to counter issues faced during drug development. Drug developers often focus on metabolism and absorption characteristics during pharmacokinetic evaluations in combination with efficacy screening studies. Besides, one may also include established in vitro studies to supplement in vivo pharmacokinetic evaluation and accelerate the pharmacokinetic testing process.
Selected candidate drug compounds undergo multiple safety tests to assess their safety and efficacy before initiating clinical trials. These safety evaluations include in vitro studies using cell culture suspensions, safety pharmacology and genotoxicity studies, and in vivo testing using mammals such as guinea pigs, monkeys, dogs, rats, etc. Additional pharmacokinetic testing also includes radio-labeled compounds for more precise and accurate analysis.
Earlier pharmacokinetic data was achieved from experimental testing in animals, and hence, they were merely supplementation with toxicity analysis. Today, with the availability of human liver samples, the importance of human in vitro testing has increased in conjunction with conventional animal testing. Today, non-clinical pharmacokinetic evaluations are delivering more vital information for assessing drug safety. These evaluations have two primary roles:
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Confirmatory assays for verifying the validity of toxicity analysis between humans and experimental animals
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Predicting side effects through human pharmacokinetic simulations
Data obtained from metabolic analysis can influence assay research and the design of clinical toxicity analysis. Researchers often determine metabolic structures to accelerate drug development projects. Usually, laboratories acquire radiolabeled compounds to determine the structures of metabolites during the preclinical stage. Notably, conducting pharmacokinetic testing before initiating preclinical toxicity tests can be beneficial for identifying the most appropriate model for toxicity analysis. Additionally, any pharmacologically active or toxic metabolite can be detected and measured during toxicokinetic and clinical testing.
In Conclusion
Pharmacokinetics helps drug developers evaluate drug safety and efficacy profile. However, adequate solutions are required to overcome challenges faced during pharmacokinetic design and conduct.
