Preliminary pharmacokinetic model of pilocarpine uptake and distribution in the eye.

A pharmacokinetic model that permits prediction of aqueous humor pilocarpine levels following topical application to rabbit eyes was developed. The model is able to account for changes in both instilled solution volume and drug concentration. The model, although simplified, relies mainly on experimentally verifiable and independently measured parameters. Its utility lies in its ability to account quantitatively for the large drainage loss of instilled drug solutions and its predictive ability regardless of the instilled volume or concentration. The framework established by this model will allow further sophistication as more experimental data become available and should be adaptable to other ophthalmic drugs.