Long-term ocular safety and systemic exposure of doxycycline hyclate ophthalmic solution in juvenile rabbits: a 270-day preclinical GLP study.

Twice-daily topical doxycycline hyclate ophthalmic solution was well tolerated in juvenile rabbits for 9 months.

No systemic or ocular toxicity was identified, establishing the No-Observed-Adverse-Effect Level (No-Observed-Adverse-Effect Level) at 0.25 mg/eye (1 mg/day).

These findings support the safety of long-term ocular exposure to doxycycline hyclate for chronic applications.