Azvudine(FNC)，a nucleoside reverse transcriptase inhibitor, make itself a better candidate to be co-formulated in other anti-HIV therapies, thus to improve patient's compliance. FNC is a broad-spectrum RNA virus inhibitor that inhibits the novel coronavirus RNA-dependent RNA polymerase (RdRp).

This is a clinical study to evaluate the Interactions between Azvudine Tablets (FNC) and Tenofovir Alafenol Fumarate Tablets (TAF) in healthy subjects. This is a single-center, randomized, open-label, three-cycles, three-treatment crossover clinical trial. Subjects was administered orally for 7 consecutive days each cycle, and the washout period between each cycle was 10 days. Biological sample collection and safety examination were performed.

Inclusion Criteria:

1. Healthy subjects aged ≥ 18 years old and ≤ 45 years old, regardless of gender;
2. Body mass index (BMI) within the range of 19.0-26.0 (including the critical value) (BMI = weight (kg) / height 2 (m2)), the weight of men should be ≥ 50.0kg, and the weight of women should be ≥ 45.0kg;
3. Those who had no birth plan within 2 weeks before screening and within 6 months after the end of the trial and agree to take effective non-drug contraceptive measures during the trial;
4. Understand and sign the informed consent form.

Exclusion Criteria:

1. Persons with allergic constitutions, history of drug or food allergies, especially those who were allergic to any ingredient in this product and its excipients;
2. Individuals with a history of hypoglycemia;
3. Individuals deemed ineligible by the clinical research physician due to significant clinical abnormalities in medical history, physical examination, laboratory tests, and other related examinations (abnormal vital sign reference ranges: seated blood pressure: systolic <90 mmHg or >140 mmHg, diastolic <60 mmHg or >90 mmHg; pulse <50 bpm or >100 bpm);
4. Individuals who smoked ≥5 cigarettes daily prior to screening;
5. Individuals with a history of alcohol abuse within the past 12 months (consuming ≥14 units of alcohol weekly: 1 unit = 285 mL of beer, or 25 mL of spirits, or 150 mL of wine), or who tested positive for alcohol on breath tests prior to study enrollment (testing value >0mg/100mL);
6. Individuals with a history of substance abuse within the past 12 months or who tested positive for addictive substances prior to enrollment;
7. Individuals required to be vaccinated against COVID-19 according to the specified schedule during the study;
8. Individuals who underwent surgery within the past 3 months, especially those who had had surgeries that would affect drug absorption, distribution, metabolism, or excretion, or those planning to undergo surgery during the study;
9. Individuals who had taken any medication that interacts with the trial drug in the 30 days prior to screening, such as methadone, propafenone, domperidone, dronedarone, quinidine, ergot alkaloids (e.g., dihydroergotamine, ergometrine, ergotamine, methylergometrine), irinotecan, lurasidone, oral midazolam, pizotifen, triazolam, felodipine, nisoldipine, ranolazine, eplerenone, cisapride, lovastatin, simvastatin, ticagrelor, dexmedetomidine, halofantrine, asimadoline, mizolastine, terfenadine, indoramine, benperidol, lacidipine, ivabradine, domperidone, and other moderate or strong CYP3A4 inducers or CYP3A4/P-glycoprotein/BCRP substrates and erythromycin, azithromycin, levofloxacin, etc.; whether a participant's use of medication within 30 days is determined by the investigator regarding its interaction with the trial drug;
10. Individuals with a history of cardiovascular, liver, kidney, pulmonary, gastrointestinal, neurological diseases, especially any surgical conditions or disorders that might affect drug absorption, distribution, metabolism, and excretion, or any surgical conditions or disorders that might pose hazards to participants;
11. Individuals with febrile illness within the 3 days prior to screening;
12. Individuals who had participated in any other clinical trials within the past 3 months;
13. Individuals with any history of prescription drugs, over-the-counter drugs, herbal medicine, or dietary supplements within 14 days prior to screening;
14. Individuals who had consumed excessive tea, coffee, and/or caffeinated, xanthine, or alcoholic beverages (more than 8 cups, 1 cup = 250 mL) daily within the 3 months prior to screening;
15. Individuals who had lost blood or donated ≥200 mL within the past 8 weeks;
16. Pregnant or breastfeeding women;
17. Individuals who could not tolerate venipuncture or had a history of vasovagal syncope;
18. Individuals deemed unsuitable for this study by the investigator.