Pharmacokinetics is a field of research dealing with the process of drug absorption, distribution, metabolism and excretion. Biomedical researchers seek to apply pharmacokinetic principles to optimize drug delivery and safety to patient populations and individual patients. The aim is to enhance the efficacy of the drug therapy while decreasing its toxicity. By defining correlations between drug concentrations and delivery methods to their pharmacologic impact, clinicians have been able to apply these principles to individual patients.
Since the impact of a given drug is often associated with its concentration (in an active, unbound state) at the site it is targeting. Determining the concentration of the drug at the receptor site can, unfortunately, be problematic, as the receptor sites are scattered across our bodies, making direct measurements of drug concentrations in the relevant locations unfeasible. What is possible is to measure drug concentrations in the blood, urine saliva and so forth.
Kinetic homogeneity is a term used to the projected relationship between measurable drug levels in these bodily fluids and their concentration at the site of their respective receptors, where they produce their pharmacogenetic effect. As concentration of the drug in the plasma (or other fluid) increases or decreases, its concentration in the relevant tissue will also increase or decrease.
When drugs therapies are developed a basic requirement is the performance of a suit of pharmacokinetic (drug concentration) assays as well as assays to determine the level of the anti-drug immune response. Multiple assays may well be required in order to plot out the appropriate PK, with ligand binding assays (LBAs) being increasingly used. Their specific protocol depends on the compound molecular weight and/or mechanism of action, utilizing very specific reagents that can recognize and bind the drug with high specificity and affinity. This enables avoiding complex pretreatment protocols common in non-LBA-methods.
Merkel will be happy to advise you on the best LBA assay for your purposes. Contact us today to learn more.