Corneal concentrations and preliminary toxicological evaluation of an itraconazole/dimethyl sulphoxide ophthalmic ointment.

This research explores the effect of topically applying an ointment consisting of 1% itraconazole, both with and without dimethyl sulphoxide (DMSO), to the eyes of horses to assess the resulting concentration of itraconazole in corneal tissue and aqueous humour, as well as to analyze the potential toxicological effects of such applications.

Key Objectives of the Research

• The study mainly aimed to identify the concentration achievable of the antifungal agent, itraconazole, in corneal tissue and aqueous humor of the eye, following its topical application as part of a 1% itraconazole ointment.
• The research also aimed to establish the influence of adding DMSO into this ointment on the achievable levels of itraconazole in the eye tissues examined.
• The study additionally intended to inspect whether any observable or histopathological eye toxicity develops as a result of topical applications of 1% itraconazole, plus-minus the addition of DMSO.

Methodology

• To answer their research questions, the scientists carried out experimental trials on six horses, all recognized as having normal eyes.
• The study incorporated a controlled design wherein each horse got one eye treated with 0.3 mL of a 1% ultra-micronized itraconazole ointment, and the other eye with 0.3 mL of a 1% itraconazole/30% DMSO ointment.
• These ointments were applied every six hours for a total of 28 treatments.
• The concentration levels of itraconazole in corneal tissue and aqueous humor of the eyes were determined through high-performance liquid chromatography.

Findings

• Both ointments were well tolerated by all the horses, with no notable or histopathological abnormalities arising during the trial.
• The concentration of itraconazole in corneal tissue averaged at 1.1 (+/- 0.4) micrograms/g in those horses treated with the ultra-micronized itraconazole ointment, and 7.9 (+/- 3.3) micrograms/g in those treated with the itraconazole/DMSO ointment.
• There was a statistically significant difference in the concentrations achieved between the two ointments – this emphasized the influence of adding DMSO to the itraconazole ointment.
• The study found no traceable levels of itraconazole in the aqueous humour in either treatment group.