General Pharmacokinetic Model for Topically Administered Ocular Drug Dosage Forms

Area of Science:

• Ocular pharmacology and drug delivery
• Pharmacokinetics and bioavailability modeling
• Computational modeling in pharmaceutical sciences

Background:

• Accurate prediction of ocular drug behavior is crucial in pharmaceutical development.
• Drug pharmacokinetics (PK) and bioavailability are influenced by formulation and physicochemical properties.
• Early in silico estimation of drug performance minimizes the need for extensive in vivo testing.

Purpose of the Study:

• To develop a physiologically relevant pharmacokinetic (PK) model for the rabbit eye.
• To simulate the impact of drug and formulation characteristics on ocular drug bioavailability and PK.
• To provide an in silico tool for optimizing ophthalmic drug formulations.

Main Methods:

• A four-compartment PK model simulating drug disposition in the rabbit eye was constructed.
• The model incorporated solid and dissolved drug in tear fluid, corneal epithelium, and aqueous humor.
• Parameter values and PK data were derived from published literature on pilocarpine and fluorometholone.

Main Results:

• The PK model accurately predicted drug concentrations in the cornea and aqueous humor for various formulations.
• Simulations demonstrated the influence of formulation and physicochemical properties on drug PK.
• A user-friendly graphical interface facilitates easy parameter modification for simulating diverse formulations.

Conclusions:

• The developed PK model is a valuable tool for ophthalmic formulation development.
• The model aids in the planning and design of bioequivalence studies for ocular drugs.
• In silico PK modeling offers an efficient approach to predict ocular drug behavior.