This phase I study in healthy participants aims to assess the pharmacokinetics of midazolam and atorvastatin when administered alone and in combination with HRS-1301, and to assess the safety of HRS-1301 when administered alone and in combination with midazolam or atorvastatin.

Inclusion Criteria:

1. Subjects must be aged ≥ 18 years and ≤ 55 years on the day of signing the informed consent form (ICF);
2. At screening, body mass index (BMI) must be ≥ 19.0 kg/m² and < 28 kg/m², with body weight ≥ 50.0 kg for males and ≥ 45.0 kg for females;
3. Physical examination, vital signs, electrocardiogram (ECG), posteroanterior and lateral chest X-ray/CT, abdominal ultrasound, and laboratory tests (including complete blood count, blood biochemistry, urinalysis, coagulation function, and thyroid function) were normal or abnormal but of no clinical significance;
4. Female participants must not be pregnant or lactating and must have negative pregnancy test results prior to investigational drug administration; participants must have had no unprotected sexual intercourse within two weeks prior to screening; female participants of childbearing potential and male participants with partners of childbearing potential must agree to comply with the contraception requirements for the duration specified in the protocol and have no plans to donate sperm or eggs;
5. Subjects who understand the study procedures and methods, voluntarily agree to participate in this trial, and provide written informed consent (ICF).

Exclusion Criteria:

1. Subjects with previous medical history or current diagnosis of cardiovascular, respiratory, digestive, urinary, hematological, endocrine, infectious, immunological, malignant neoplastic, neurological, or psychiatric/metabolic disorders/dysfunctions, or any other disease;
2. Subjects who have gastrointestinal, hepatic, renal, or other known diseases that may affect drug absorption, distribution, metabolism, or excretion, or that may reduce compliance;
3. Subjects who have experienced severe trauma or undergone major surgery within 3 months prior to screening, or who plan to undergo surgery during the trial period;
4. Subjects with a history of specific allergies, or with an allergic constitution, or with known hypersensitivity to any component of the investigational drug;
5. Subjects who have used any medication within 2 weeks prior to screening, or who are still within 5 half-lives of any medication at the time of screening;
6. Subjects who have participated in any other clinical trial of a drug or medical device within 3 months prior to screening, or who are still within 5 half-lives of a prior investigational drug at the time of screening;
7. Subjects who have donated blood ≥ 200 mL or experienced significant blood loss (≥ 400 mL) within 4 weeks prior to screening, or who have received a blood transfusion within 8 weeks prior to screening;
8. Subjects who have received a live (attenuated) vaccine within 4 weeks prior to screening or plan to receive such a vaccine during the trial period.