*2.3. Plasma Pharmacokinetic Studies*

CTE, NGTS, and CNP powders were dissolved using saline, and were orally dosed at 50 mg·kg −1 , 60 mg·kg −1 , and 50 mg·kg <sup>−</sup><sup>1</sup> CTE + 60 mg·kg <sup>−</sup><sup>1</sup> NGTS, respectively, whereas saline was administered to the vehicle group. Six rats were used in each group, and all rats fasted overnight but had free access to water prior to treatment. A terminal sampling design was used to collect blood samples at 0 (pre-dose), 0.08, 0.16, 0.25, 0.5, 1, 2, 3, 4, 6, 8, 12, 24, 48, 72, and 96 h. At each time, 0.5 mL of blood was collected in the heparin sodium tubes. Plasma was separated by centrifugation at 4000 rpm for 10 min and stored below −80 ◦C until bioanalysis. Oasis PRiME HLB SPE cartridges (1 cc/30 mg, Waters, Milford, MA, USA) were used to process the plasma samples (Supplementary Materials).
