This is a single center, randomized, double-blind, placebo-controlled, dose escalation study.

Inclusion Criteria:

• Healthy male volunteers.
• aged ≥ 18 and ≤ 65 years old.
• With all clinical laboratory examination normal.
• Voluntary signing of the informed consent form.

Exclusion Criteria:

• With a history of asthma and allergic reactions.
• With a history of conjunctivitis and keratitis, as well as previous medical conditions.
• With positive results from alcohol breath or urine drug abuse testing.