[Pharmacokinetics and bioequivalence assessment of a self-assembled asparaginase nanocapsule in rats].

Objective: To study the pharmacokinetics and bioequivalence of asparaginase loaded in hyaluronic acid-graft-poly(ethylene glycol)/ sulfobutylether-β-cyclodextrin nanocapsules (AHSP) in SD rats.
Methods: The morphology of AHSP was observed under the transmission electron microscope and the particle size and zeta potential were measured. AHSP and free asparaginase were intravenously injected in rats, and the plasma asparaginase activity was measured at different time points after the injections. The pharmacokinetic parameters were calculated using the software DAS 2.1.1 to assess the bioequivalence of AHSP and free asparaginase.
Results: AHSP had an average particle size of 413.80∓10.97 nm with a zeta potential of -20.37∓2.38 mV. The AUC(0-48 h) of AHSP and free asparaginase was 137.34∓1.82 U/mL and 46.38 ∓1.98 U/mL, and their AUC(0-∞) was 164.66∓6.88 U/mL and 51.44∓3.01 U/mL with half-lives of 4.62∓0.60 h and 1.86∓0.38 h, respectively. Compared with free AN, AHSP exhibited increased AUC(0-48 h), AUC(0-∞), and half-life by 2.24, 2.55 and 2.32 folds, respectively. The 90% confidential intervals of AUC(0-48 h), AUC(0-∞) and Cmax of the tested formulation were 75.0%-76.5%, 74.3%-76.1%, and 95.1%-96.7%, respectively.
Conclusion: AHSP can improve the bioavailability and extend the biological half-life of asparaginase in rats, and AHSP and free asparaginase are not bioequivalent.