Evaluation of the in vivo behaviour of gentamicin sulphate ocular mini-tablets in ponies.

The research studies the comparison between the use of gentamicin sulphate ocular mini-tablets and eye drops in ponies, focusing on their in vivo reactions, irritation levels and gentamicin sulphate concentration over time. The results suggest that the mini-tablets produce less irritation, the increase in the concentration of gentamicin sulphate is less abrupt and remains at a sufficient level for a longer duration compared to eye drops.

Objective and Methodology

• The study’s objective was to understand the living behavior of 5% gentamicin sulphate ocular mini-tablets (2-mm diameter, 6.525 mg weight) and compare it with gentamicin eye drops in ponies.
• 6 ponies were used for the experiment, where two mini-tablets were inserted into the right eye and a comparable dose of gentamicin was administered via eye drops in the other eye.
• The researchers assessed the irritation caused by both the mini-tablets and the eye drops with a visual analog scale that ranged from 0 to 10.
• To determine the concentration of gentamycin sulphate, tears were sampled for one minute using ophthalmologic absorption triangles through a microbiological plate diffusion method.

Results

• The irritation caused by the mini-tablets was minor and clinically acceptable with an overall median score of 1.7 (± 1.4).
• Use of eye drops led to a sharp increase in the concentration of gentamicin sulphate (364.4 µg/mL after 5 minutes) but this was followed by a fast decline (10.8 µg/mL after 60 minutes).
• The increase in concentration caused by the ocular mini-tablets was less drastic (up to 56.2 microg/mL after 30 minutes) and followed by a gradual decrease. Nonetheless, the concentration remained above 15 microg/mL for 8 hours.

Conclusion

• Based on the study, ocular 5% gentamicin sulphate mini-tablets are clinically well-tolerated in ponies.
• The study demonstrated that these mini-tablets assure a constant concentration in the tears for at least 8 hours.
• Therefore, it provides a fundamental perspective on the potential advantages of using gentamicin sulphate ocular mini-tablets over eye drops, particularly in terms of gentamicin sulphate concentration and irritation.