Tacrolimus 0.1% Ophthalmic Suspension: Corneal and Intraocular Penetration Study

Area of Science:

• Ophthalmology
• Pharmacology
• Corneal Science

Background:

• Topical tacrolimus is used for ocular surface pathologies as a corticosteroid-sparing agent.
• It may prevent corneal graft rejection and inflammatory diseases.
• Its penetration is theoretically limited by hydrophobicity and high molecular weight.

Purpose of the Study:

• To investigate corneal and intraocular penetration of 0.1% tacrolimus ophthalmic suspension.
• To determine tacrolimus concentrations in various ocular tissues and plasma.
• To assess the potential of topical tacrolimus in ophthalmic applications.

Main Methods:

• Rabbits received topical 0.1% tacrolimus twice daily for 5 days.
• Ocular tissues (cornea, iris, etc.), aqueous humor, and plasma were collected at 2, 6, 11, and 24 hours post-instillation.
• Tacrolimus concentrations were quantified using high-performance liquid chromatography-tandem mass spectrometry.

Main Results:

• Maximum tacrolimus concentrations were observed at 2 hours post-instillation.
• Highest concentrations were found in the corneal epithelium, followed by the endothelium.
• Concentrations in corneal tissues exceeded the lower limit of efficacy for solid organ transplantation.

Conclusions:

• Topical 0.1% tacrolimus demonstrates significant corneal penetration.
• Achieved concentrations support its potential as a corticosteroid alternative.
• It may be beneficial for preventing endothelial graft rejection and managing inflammatory eye diseases.