A Study to Evaluate the Drug-Drug Interaction Between KL0011034 Injection and Alfentanil Hydrochloride Injection in Participants With Moderate-to-Severe Non-Cancer Chronic Pain

Inclusion Criteria: 1. Those who fully understand the purpose, content, process and possible risks of the trial, and voluntarily participate and sign the informed consent form; 2. Male and female patients with moderate to severe non-cancerous chronic pain (such as patients with shoulder inflammation, chronic back pain, myofascial pain syndrome) aged between 18 and 55 years (inclusive of the boundary values), with a NRS score of \>= 4; 3. Male weight not less than 50.0 kg, female weight not less than 45.0 kg; Body Mass Index (BMI) within the range of 19.0 to 26.0 kg/m2 (including the critical value); 4. From the date of signing the informed consent form to the last administration of the trial medication within 3 months, the trial participants (and their partners) have no plans for conception, and the trial participants have no plans for sperm donation/egg donation; From the date of signing the informed consent form to the completion of the exit examination, the participants voluntarily adopt non-pharmacological contraceptive measures; After the exit examination to the last 3 months after the last administration of the trial medication, the participants voluntarily adopt effective contraceptive measures; 5. Able to communicate well with the researchers, willing and able to comply with the lifestyle restrictions stipulated in the protocol, and cooperate to complete the trial process. Exclusion Criteria: 1. Known to be allergic to alfentanil or other opioid analgesics, etomidate or other anesthetic drugs, or to be of allergic constitution (such as allergy to two or more drugs, food or pollen), or prone to develop rashes, urticaria, etc., or having a history of allergic diseases, or known to be allergic to the excipients or raw materials of this product; 2. Having a history of head trauma, possible intracranial hypertension, cerebral aneurysm, cerebrovascular accident, or mental illness such as schizophrenia, mania, bipolar disorder, mental confusion, long-term use of psychotropic drugs or cognitive dysfunction; 3. Having a history of serious cardiovascular diseases (such as hypertension, heart failure, severe arrhythmia, etc.) and/or heart diseases, family history of heart disease and/or unstable angina pectoris, or having had a myocardial infarction in the past 6 months; 4. Having a history of other cardiovascular, endocrine, respiratory, digestive, urinary, nervous, hematological and/or lymphatic system diseases, and the investigator considers that it still …