Knowing a drug’s potential for partitioning is critical in situations where the test drug has a high Log P (lipophilic). In this situation a significant portion of the drug may be taken up and held by red blood cells (RBCs). Does plaquenil help Plasmodium resistance to chloroquine Plaquenil anger The time to peak concentration and the maximum concentration varied in various tissues and were higher than for plasma and red blood cells. 3. 3. The tissue to plasma concentration ratio increased with time up to 144th hr for some tissues while this ratio was still increasing at the 168th hr for other tissues. 4. 4. Oct 25, 2012 The drug is extensively distributed, with a volume of distribution of 200 to 800 L/kg when calculated from plasma concentrations and 200 L/kg when estimated from whole blood data concentrations being 5 to 10 times higher. Chloroquine is 60% bound to plasma proteins and equally cleared by the kidney and liver. From the saliva plasma relationship, the extent of chloroquine binding to plasma proteins was estimated to be 47%. The C max and AUC 0–6 day values obtained from saliva data was about half those from plasma, while the T max obtained from both fluids remained the same. When the combined knowledge of protein binding and blood partitioning is understood investigators can make a better determination about whether they should collect whole blood, plasma, or serum for assaying pharmacokinetic behavior of the drug if animal or clinical ADME studies. For this reason, more informative data describing drug distribution in blood can be obtained by determining both the blood partitioning ratios and direct protein binding. Chloroquine blood to plasma ratio Protein Binding and Blood To Plasma Ratio Cell., Clinical Pharmacokinetics and Metabolism of Chloroquine. Reading oct screening results plaquenil Verapamil, chloroquine Figure 1 and 2 Detection method LC-MS/MS with internal standard Results blood to plasma ratio Figure 1. Blood to plasma ratio obtained for two reference compounds in 3 different species Figure 2. Comparison of in-house human blood to plasma ratio with literature values 1,2 1 Obach 1999, Drug Metab Dispos 27, 1350 ADME Blood Partitioning - Fidelta.eu. Pharmacokinetics of chloroquine Saliva and plasma levels.. Comparison of the partitioning in vitro of chloroquine and.. For example, the clearance of CQ from whole blood and plasma is approximately 0.1 to 0.25 liter/h/kg of body weight and 0.5 to 0.9 liter/h/kg, respectively, in healthy volunteers, and the t 1/2 of CQ is 150 to 290 h 17–19, 32, 35, 47, 59. Therefore, determining the blood-to-plasma ratio is important for deciding whether plasma or whole blood would provide more physiologically relevant pharmacokinetic parameters. For these studies, chloroquine is used as a positive control. Caco-2 Permeability Studies The objective of this study was to predict R b blood/plasma ratio in humans using a simple method. Human and rat R b and free fraction in plasma f p values were obtained from the literature. The ratio of total red blood cell concentration to the free concentration in plasma K b was calculated using f p and R b.