ABSTRACT
References .......................................................................................................................... 543
Successful delivery of drugs into the eye is extremely complicated because the eye is
protected by a series of complex defense mechanisms that make it difficult to achieve an
effective concentration of the drug within the target area of the eye. Drugs delivered in
classical ophthalmic dosage forms (eye drops) into the lower cul-de-sac have a poor
bioavailability due to these complex defense mechanisms. Furthermore, drugs administered
systemically for their ocular action have poor access to the eye tissue because of the blood-
aqueous barrier, which prevents drugs from entering the extravascular retinal space and the
vitreous body [1,2].
