Page 105 - Pharmaceutics IV (02-06-01305)

Ophthalmic DD: routes & pharmacokinetics

• Disadvantages:
➢ Inefficient bioavailability: it is generally less than 5%-10% of the

administered dose due to:
❑ Nasolacrimal drainage
❑ Nonproductive, noncorneal loss (systemic side effects)
❑ Protein binding in the lacrimal fluid (protein-drug complex!)

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Ophthalmic DD: routes & pharmacokinetics

Fate of topically delivered drugs

Corneal/transcorneal absorption
• It is the main absorption site for most drugs into the anterior chamber

of the eye to the aqueous humor.
• Transcorneal drug absorption is highly dependent on a drug’s

physicochemical properties & the formulated dosage form.

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Salma E. EL-Habashy