Efficacy and Safety Study of Meloxicam Nanocrystal Injection for the Treatment of Moderate to Severe Pain

In this study, a randomized, double-blind, placebo-controlled multicenter study will be conducted to evaluate the efficacy and safety of meloxicam nanocrystal injection in subjects with moderate to severe pain after abdominal surgery.

Inclusion criteria

• 18 years ≤ age ≤ 65 years, regardless of gender.
• Elective abdominal surgery under general anesthesia.
• ASA score of grade 1-3.
• 18 kg/m^2 < BMI < 30 kg/m^2.
• NRS score of ≥ 4 within 3 hours after the end of surgery (last suture).
• Able to understand the study process and the use of pain scales, and able to communicate effectively with study personnel.
• Written informed consent signed by subject or legal representative.

Exclusion criteria

• Abnormal liver function: ALT and/or AST > 2 × ULN, or TBIL ≥ 2 × ULN.
• Renal impairment (blood creatinine > 1.5 × ULN), or dialysis treatment within 28 days prior to the surgery.
• Subjects at high risk of bleeding, including subjects with congenital bleeding disorders (e.g., hemophilia), thrombocytopenic subjects (platelet count less than 50 × 10^9/L), subjects with abnormal platelet function (e.g., idiopathic thrombocytopenic purpura, disseminated intravascular coagulation, congenital abnormal platelet function), or subjects with any clinically significant active bleeding.
• Abnormal coagulation (PT>ULN+3s and/or APTT>ULN+10s).
• Subjects with a history of severe gastrointestinal disease (e.g. ulcers, bleeding and perforation, etc.) within 1 year prior to randomization that may be worsened by the administration of NSAIDs-like drugs.
• Myocardial infarction or coronary artery bypass grafting within 1 year prior to randomization.
• Abnormal clinically significant 12-lead ECG during the screening period and judged by the investigator to be inappropriate for participation in this trial.
• Combination of severe liver, kidney, cardiovascular, cerebrovascular, or metabolic system disease, which is judged by the investigator to be inappropriate for participation in this trial.
• Subjects with combined neurological or psychiatric disorders such as migraine and seizures, which have been judged by the investigator to affect the evaluation of the efficacy of the trial drug.
• Subjects with hypertension whose blood pressure is not satisfactorily controlled by antihypertensive medication (screening period sitting systolic blood pressure ≥ 160 mmHg, and/or screening period diastolic blood pressure ≥ 100 mmHg).
• Sitting systolic blood pressure ≤ 90 mmHg at screening.
• Subjects with diabetes mellitus whose blood glucose is not satisfactorily controlled (random blood glucose ≥ 11.1 mmol/L during the screening period).
• Subjects with advanced malignancy or malignancy with extensive metastases.
• Combined with other physical pain conditions that may confound postoperative pain evaluation.
• Subjects with known hypersensitivity to meloxicam, any of the excipients in the study drug, aspirin, other non-steroidal anti-inflammatory drugs (NSAIDs), any perioperative drug use, or other history of anaphylactic reactions.
• Subjects with alcohol or drug dependence within 3 months prior to screening and/or subjects whose alcohol, drug, or medication withdrawal may interfere with efficacy and safety evaluations during the study period.
• Subjects who have undergone abdominal surgery within 6 months prior to randomization.
• Subjects who have participated in other clinical trials and received the test drug/test device within 3 months prior to randomization.
• Subjects with contraindications to investigational drugs, standard anesthetic practices.
• Women who are pregnant or breastfeeding.
• Other reasons that the investigator deems inappropriate for participation in the trial.