Non-invasive assessment of ocular pharmacokinetics using Confocal Raman Spectroscopy

Area of Science:

• Ophthalmology
• Pharmacokinetics
• Spectroscopy

Background:

• Ocular drug delivery requires precise pharmacokinetic understanding.
• Non-invasive methods are crucial for in vivo studies.
• Corneal hydration impacts drug absorption and efficacy.

Purpose of the Study:

• To quantify drug transport through the rabbit cornea in vivo using LSCRS.
• To monitor the effect of Trusopt on corneal hydration.
• To evaluate LSCRS as a tool for ocular pharmacokinetics.

Main Methods:

• Topical application of Trusopt 2% to rabbit corneas.
• Real-time monitoring of drug-specific Raman signal amplitude using LSCRS.
• Quantification of pharmacokinetic variables and corneal hydration changes.

Main Results:

• LSCRS provided sensitive and reproducible real-time monitoring of Trusopt concentration.
• Bi-phasic drug concentration-time curves indicated nonproductive tear loss and corneal stroma transfer.
• Trusopt induced an acute dehydrating effect, decreasing corneal hydration by ~15%.

Conclusions:

• LSCRS is a specific, sensitive, and reproducible tool for in vivo ocular pharmacokinetic studies.
• The study quantified Trusopt's transport kinetics and its effect on corneal hydration.
• LSCRS offers valuable spatial resolution for detailed ocular drug delivery research.