A modified serial blood sampling technique and utility of dried-blood spot technique in estimation of blood concentration: application in mouse pharmacokinetics

Abstract

Pharmacokinetic (PK) studies in mice usually require discrete and parallel blood sampling owing to a restriction on the volume of blood that can be withdrawn. This results in dosing large number of animals and generating composite PK profile. To reduce the number of animals and generate individual animal PK profiles, we developed a serial sampling technique via tail vein bleeding in mice, in which only 20-30 μL blood was withdrawn per time point. Due to the small blood volume, a dried-blood spot (DBS) technique was applied for sample processing. The utility of this technique was demonstrated using three test compounds (amodiaquine, chloroquine and chlorthalidone), with varying degrees of blood-to-plasma partition ratios. The PK studies were carried out in male Balb/c mouse weighing 25-30 g. The compounds were administered intravenously via the saphenous vein. Blood was collected by composite (retro-orbital plexus) or serial (tail vein bleeding) sampling techniques at different time points. Blood samples were processed as blood lysate or DBS. Blood or plasma samples were analyzed by sensitive and rapid UPLC-MS/MS methods. The blood concentrations (both from blood lysate and DBS) obtained from serial sampling matched with those from composite sampling. The ratio of blood AUC to plasma AUC correlated well with the in vitro blood-to-plasma partition ratio of the compounds. The systemic clearance and volume of distribution at steady state calculated from blood or plasma AUCs were in proportion to the respective AUCs. Our results indicated that the serial sampling technique would reduce the number of animals and also compound usage, as well as improve the quality of pharmacokinetic data. Also, the serial sampling technique does not require the use of anesthesia and allows estimation of inter-animal variability in PK. A small volume serial sampling is possible due to the availability of the DBS technique.

Using Improved Serial Blood Sampling Method of Mice to Study Pharmacokinetics and Drug–Drug Interaction

“…Soon after the administration, the plasma concentration obtained from the lateral tail vein following administration via the lateral tail vein opposite to the blood sampling site was higher than that of the lateral tail vein following administration via the femoral vein (data not shown). This result indicated that blood sampling from the lateral tail vein after administration via the opposite lateral tail vein would be contaminated in spite of different sites being used for administration and sampling, as reported previously . We, therefore, selected the femoral vein as an alternative to the lateral tail vein, which is the conventional dosing route for intravenous administration.…”

Impact of Extended Duration of Artesunate Treatment on Parasitological Outcome in a Cytocidal Murine Malaria Model

“…In mice, dihydroartemisinin, the metabolite of artesunate, has a half-life of 25 min, while piperaquine has a significantly longer half-life of 18 days (42,43). Amodiaquine has a half-life of 2.8 h in mice, but it is rapidly metabolized to desethylamodiaquine, which has a half-life in humans of 10 days (44,45). By using this cytocidal murine model of malaria, we determined that extending the interval of 3 doses of artesunate from spanning one asexual cycle to spanning three asexual cycles resulted in a significantly greater reduction in parasite density from the same total amount of drug.…”

NIR-emissive PEG-b-TCL micelles for breast tumor imaging and minimally invasive pharmacokinetic analysis

“…This novel method was minimally invasive, highly robust, and enabled accurate PK determination from small blood volumes (< 20 μL), obviating the need for repeated anesthesia and imaging, for regular tail-vein bleeding, or for the sacrifice of a multitude of mice (22). …”

“…A common limitation encountered in many preclinical PK studies is the necessity to sacrifice a multitude of animals at different time points in order to collect both organs and blood samples for nanoparticle and drug analyses (22–25). We have previously shown that whole-body NIR-based optical imaging is an inexpensive and easy to use imaging modality that enables noninvasive in vivo biodistribution studies to be conducted in mice (3, 17).…”