It is critical to understand a drug’s potential for partitioning in situations where the test drug has a high Log P (lipophilic). In this case, a large portion of the drug may be taken up and held by red blood cells (RBCs). For this reason, more informative data describing drug distribution in the blood can be obtained by measuring both the blood partitioning ratios and direct protein binding. When the comprehensive knowledge of protein binding and blood partitioning is understood, investigators can make a better determination about appropriate biological fluid, either whole blood, plasma, or serum should be collected to analyze the pharmacokinetic behavior of the drug.
Since certain compounds show specific binding to blood cells, choosing the most appropriate concentration to measure blood partitioning is crucial. If the concentration is too high, binding sites in the blood will be saturated and the partitioning cannot be effectively observed; if it is too low, the detection issues start to become apparent and the physiologically relevant range is missed. In addition, RBCs contain a variety of enzymes that can metabolize many drugs. Thus, the processing of blood samples should be done in accord with a protocol that is based on the results of previous studies, establishing the interaction between RBCs and the drug being developed. Sample protocols should specify the centrifugation time, temperature, and pH conditions, as well as need for addition of enzyme inhibitors. At Creative Bioarray, the red blood cell partitioning assay provides a specific and robust approach to assess these parameters using fresh blood from human and preclinical species.
Creative Bioarray has an experienced team of experts dedicated to providing customers with the most reliable and highest quality services. The red blood cell partitioning is one of our in vitro ADME screening services. Please contact us for further information.