Shanghai Fengqi Industrial Investment Co., Ltd.

To evaluate the pharmacokinetic characteristics of single and multiple intravenous infusions of acetaminophen injection (100ml: 1000mg) in healthy Chinese volunteers, as well as its safety after administration, and to compare it with oral preparations to provide a basis for further research.

Primary purpose: To evaluate the effectiveness of acetaminophen injection for postoperative analgesia Secondary purpose: To evaluate the safety of acetaminophen injection for postoperative analgesia. To explore the reasonable dose of acetaminophen injection for postoperative analgesia.

Primary objective: To evaluate the pharmacokinetic characteristics of single or multiple intravenous infusions of different doses of acetaminophen injection in healthy subjects. Secondary objective: To evaluate the safety of single or multiple intravenous infusions of different doses of acetaminophen injection in healthy subjects; To compare the pharmacokinetics of acetaminophen tablets taken orally.