Meal timing may change how this drug works

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: 1. 18 to 45 years old (including 18 and 45 years old), gender is not limited; 2. Male subjects weighing ≥50.0 kg, female subjects ≥45.0 kg, with body mass index (BMI) between 19.0 and 25.0 kg/m2 (including borderline values); 3. Fully understand the content of the trial, the test drug, the trial process, etc, and be able to communicate well with the researcher, willing to comply with the study regulations, participate in the trial voluntarily and sign an Inform consent. Exclusion Criteria: 1. Those with a history of severe allergies (e.g, angioedema and anaphylaxis), allergies (Screening Consultation/Admission Consultation) Those with a history of severe allergy (e.g, angioedema and anaphylaxis), allergy (e.g, allergy to pollen, two or more medications/foods), or history of food or drug allergy or other metabolic disorders (e.g, asthma, hives, eczematous dermatitis, etc.) judged by the investigator to be clinically significant, or a known allergy to JAK inhibitors or an allergy to excipient components of the test medication; 2. Abnormal and clinically significant results of physical examination, vital signs, 12-lead electrocardiogram, laboratory tests (including routine blood, blood biochemistry, urine routine, blood pregnancy (only for women of childbearing age), infectious disease screening, antinuclear antibody, coagulation function, tuberculosis antibody, chest X-ray, abdominal ultrasound) prior to enrolment; 3. QTcF \> 440 ms for males and \> 460 ms for females on ECG during the screening period; 4. Those who have undergone major surgical procedures within 3 months prior to screening or plan to undergo surgery during the trial period; 5. Acute illness within 2 weeks prior to screening; clinically significant infection (e.g, upper respiratory tract infection, nasopharyngitis, urinary tract infection, etc.) within 3 months prior to screening; evidence of any infection within 7 days prior to screening; history of herpes simplex infection, or recurrent (\>once) herpes zoster or disseminated herpes zoster; 6. History of any clinically serious disease or any disease or condition that, in the opinion of the investigator, may affect the outcome of the trial, including but not limited to a history of circulatory, endocrine, neurological, gastrointestinal, urinary, or haematological, immunological, psychiatric, and metabolic disorders; 7. Dysphagia or any history of gastrointestinal disorders (or gastrointestinal resection, etc.) affecting drug absorption; 8 . Those with irregular bowel movements and habitual constipation or diarrhoea; 9\. Those with a history of lipid metabolism defects, such as: familial hyperlipidaemia, lipoid nephropathy, or patients with acute pancreatitis accompanied by hyperlipidaemia; 10. Those with a positive combined urine multi-drug test (including morphine, methamphetamine, ketamine, methylenedioxyamphetamine, tetrahydrocannabinolic acid); 11. Those with a history of previous drug abuse or drug dependence; 12. Anyone who has been vaccinated within 8 weeks prior to screening or who plan to be vaccinated during the course of the study or within 8 weeks of administration of study drug; 13. Anyone who has donated or lost ≥400 mL of blood or received a blood transfusion within 3 months prior to screening; or anyone who has donated blood or blood components within 1 month of the planned end of the trial; 14. Those with special dietary requirements or those who are unable to comply with the uniform dietary and appropriate regulations of the study center; 15. Those who have smoked more than 3 cigarettes/day or equivalent amount of tobacco in the 3 months prior to screening; or who have consumed ≥14 units of alcohol per week (1 unit equals to 17.5mL or 14g of pure alcohol, which is approximately equal to 35mL of 50° white wine or 350mL of 5° beer); or who do not agree to abstain from smoking or drinking alcohol for the duration of the trial; or those who have a positive result from an alcohol breathalyzer test; 16. Any person who has taken any prescription drug, over-the-counter drug, any vitamin product or herbal medicine (JAK inhibitor, immunosuppressant, etc.) within 14 days prior to screening; 17. Those who have combined strong inducers of liver metabolism enzymes (e.g, omeprazole, barbiturates, carbamazepine, amiloride, pallidomycin, aminoglutethimide, phenytoin, grumet, rifampicin, sulfinpyrazone, roxithromycin, etc.) within the 4 weeks (28 days) prior to Screening, or any other history of medication use that in the judgement of the Investigator has the potential to interfere with in vivo pharmacokinetics of the test drug. Anyone who has taken any drug known to cause prolongation of the QT/QTcF interval or a drug with a risk of causing torsades de pointes (TdP) within 4 weeks (28 days) prior to Screening; or drugs with a long half-life; 18. Anyone who consumed any food or drink containing caffeine (e.g. coffee, strong tea, cola, chocolate, etc.) or food containing grapefruit juice that may have an effect on metabolising enzymes or who consumed food or drink containing alcohol within 48 h prior to the administration of the drug; 19. Those who are participating in other clinical trials and have used an investigational drug, vaccine or device within 3 months prior to the first dose; 20. Pregnant or breastfeeding women or women of childbearing age who have had unprotected sex within 14 days prior to screening; 21. The subject or his/her partner is unwilling to use non-pharmacological contraception (e.g, total abstinence, condom, IUD, ligation, etc.) for contraception during the trial period or the subject and/or his/her partner has a pregnancy plan within 3 months of the administration of the study drug; 22. The subject may not be able to complete the study for other reasons or there are other factors that, in the opinion of the investigator, make participation in the trial unsuitable.