Preliminary pharmacodynamics
At 0.25 h before and 0.25, 1, 4, 8, 10, 12, 14, 18, 21, 24, 27, 30, 33, 36, 48 and 72 h after administration, the analgesia intensity was measured by acupuncture on circles 1 and 2 of the abdomen, and the onset time and effective duration were evaluated. The distance between two adjacent injection sites was recorded.