Pharmacokinetics and tissue distribution study of 16-dehydropregnenolone liposome in female mice after intravenous administration

Abstract

Objective: 16-Dehydropregnenolone (16-DHP) is a potential antitumor compound with poor solubility. A liposome entrapped 16-DHP (16-DHP-LM) formulation was developed to surmount its solubility obstacle. The aim of this study is to investigate the pharmacokinetics of 16-DHP-LM and 16-DHP solution in female mice and tissue distribution of 16-DHP-LM in female tumor-bearing nude mice.

Methods: Rotary-evaporated film method was used to prepare 16-DHP-LM. The comparison of pharmacokinetics between 16-DHP-LM and 16-DHP solution in female mice was investigated after intravenous administration at a single dose of 15 mg/kg. The dose proportionality of 16-DHP-LM was also evaluated after intravenous administration of 16-DHP-LM at the doses of 7.5, 15.0 and 30.0 mg/kg. The tissue distribution of 16-DHP-LM in female tumor-bearing nude mice was evaluated after intravenous administration of 16-DHP-LM at a single dose of 30.0 mg/kg.

Results: The pharmacokinetic study indicated that the 16-DHP-LM group had higher area under the plasma concentration-time curve (AUC), lower apparent volume of distribution (Vz) and smaller systemic clearance (CL) than the 16-DHP solution group. For dose proportionality, good linearity of the pharmacokinetics of 16-DHP after intravenous administration of 16-DHP-LM was observed in the regression analysis of the AUC-dose plot (r = 0.99) and the C_max-dose plot (r = 0.98). The tissue distribution study showed that the main tissue depots for 16-DHP in tumor-bearing nude mice were plasma, liver, spleen and tumor, which was benefit to anti-tumor effect. All these results provided a significant basis for the design of clinical trial of 16-DHP-LM.

Keywords:

• 16-Dehydropregnenolone
• liposome
• pharmacokinetics
• tissue distribution
• tumor-bearing nude mouse

Declaration of interest

We declare that we have no conflict of interest.

This work was supported by the Project of Liaoning Distinguished Professor (2014), the Program for Liaoning Innovative Research Team in University (No. LT 20121018) and Shenyang Office of Science and Technology (No. F11-148-9-00).