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Use of Rabbit Eyes in Pharmacokinetic Studies of Intraocular Drugs
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Ocular Physiologically Based Pharmacokinetic Modeling for Ointment Formulations
Maxime Le Merdy1, Jessica Spires2, Viera Lukacova2
1Simulations Plus, Inc., 42505 10th Street West, Lancaster, California, 93534, USA. maxime@simulations-plus.com.
Pharmaceutical Research
|November 20, 2020
Summary
The Ocular Compartmental Absorption & Transit (OCAT™) model predicts rabbit ocular drug pharmacokinetics from ointments. Formulation factors like surface area and release rate significantly impact drug concentration in the aqueous humor.
Area of Science:
- Ocular pharmacokinetics
- Drug delivery systems
- Computational modeling
Background:
- Understanding ocular drug pharmacokinetics is crucial for developing effective ophthalmic formulations.
- Ointment formulations present unique challenges for drug absorption and distribution within the eye.
Purpose of the Study:
- To demonstrate the utility of the Ocular Compartmental Absorption & Transit (OCAT™) model in GastroPlus® for characterizing ocular drug pharmacokinetic performance.
- To evaluate the rabbit model for assessing ophthalmic ointment formulations.
Main Methods:
- Developed and applied a new OCAT™ model for fluorometholone and utilized a verified dexamethasone model.
- Characterized aqueous humor (AH) concentrations after administering multiple ointment formulations in rabbits.
- Incorporated parameters such as application surface area, application time, and Higuchi release constant.
Main Results:
- Parameter sensitivity analysis revealed significant impacts of formulation changes on ocular exposure.
- Application surface area and Higuchi release constant influenced maximum concentration and overall ocular exposure.
- Application time affected the time to reach maximal AH concentration.
Conclusions:
- This OCAT™ model for ophthalmic ointments is a foundational step in understanding drug behavior in the eye.
- The model aids in elucidating the relationship between physiological factors, formulation properties, and in vivo ocular pharmacokinetics.
- Provides insights into rabbit ocular drug performance for ointment-based therapies.
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