This is a Single-Center, Randomized, Double-Blind, Placebo-Controlled Phase I Study to Evaluate the Safety, Tolerability, and Pharmacokinetic Profile of RC017 Ophthalmic Ointment Following Single and Multiple Doses in Healthy Adult Participants.RC017 is a small-molecule drug, being developed as a novel therapeutic treatment for patients with Dry Eye Disease (DED) . This study aims to evaluate the safety, tolerability and pharmacokinetics of RC017 after Single and Multiple Doses.

Inclusion Criteria:

1. Healthy male and female trial participants aged 18 to 55 years old (inclusive);
2. Body Mass Index (BMI) ranging from 19.0 to 26.0 kg/m² (inclusive), with body weight ≥ 50 kg for males and ≥ 45 kg for females;
3. At screening, best corrected visual acuity (BCVA) of both eyes should be ≥ 1.0; in addition, ophthalmic examinations (including assessment of ocular symptoms, slit-lamp microscopy/external eye examination, corneal fluorescein staining, funduscopy, and intraocular pressure measurement) should show no abnormalities in both eyes, or any abnormalities detected should be judged as clinically insignificant by the investigator;
4. Have a full understanding of the trial procedures, voluntarily participate in the trial, and sign a written informed consent form (ICF);
5. Female participants with childbearing potential must have a negative result in the serum pregnancy test at screening. Throughout the entire study period and within 3 months after the study conclusion, all female participants, male participants and their sexual partners must agree to adopt effective contraceptive measures (Note: Contraceptive measures include both pharmacological and non-pharmacological methods, see Appendix 4 for details).

Exclusion Criteria:

1. History of ocular diseases deemed by the investigator as unsuitable for enrollment, including but not limited to dry eye, glaucoma, blepharitis, meibomianitis, allergic conjunctivitis, iritis, uveitis, and/or active ocular inflammation or infection.
2. Prior history of ocular surgeries, including laser refractive surgery and intraocular surgery, etc.
3. Participants who wore contact lenses or cosmetic colored contact lenses within 2 weeks prior to screening, or those requiring contact lens wear during the trial.
4. Use of any prescription or over-the-counter (OTC) medications (including vitamins, antacids, Chinese herbal medicines, dietary supplements, and topical ophthalmic drugs) within 2 weeks prior to screening.
5. Clinically significant abnormalities in vital signs, physical examination findings, laboratory test results (complete blood count [CBC], urine routine, blood biochemistry, coagulation function, infectious disease screening, serum pregnancy test [females only]) or 12-lead electrocardiogram (ECG), as judged by the investigator.
6. History of diseases involving the central nervous, mental, cardiovascular, renal, hepatic, respiratory, metabolic, or musculoskeletal systems, which in the investigator's judgment may compromise participant safety or interfere with study results.
7. Clinically significant history of allergies, especially drug allergies, or known hypersensitivity to any component of the study drug.
8. Daily cigarette smoking > 5 sticks within 3 months prior to the trial.
9. Suspected or confirmed alcohol dependence; average daily alcohol intake > 2 units within 3 months (1 unit = 10 mL pure ethanol, equivalent to 200 mL beer [5% alcohol], 25 mL spirits [40% alcohol], or 83 mL wine [12% alcohol]); or positive alcohol test result.
10. History of drug abuse; or positive urine test for ketamine, morphine, methamphetamine, MDMA, or tetrahydrocannabinol carboxylic acid (THC-COOH).
11. Participation in another clinical trial within 3 months prior to screening.
12. Blood donation or blood loss ≥ 400 mL within 3 months prior to screening.
13. Pregnant or lactating females.
14. Unsuitability for venous blood collection.
15. Vaccination within 30 days prior to screening, or planned vaccination during the study period.
16. Any other conditions deemed by the investigator as unsuitable for enrollment.