Page 125 - Pharmaceutics IV (02-06-01305)
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Ophthalmic DD: Excipients
Why?
• To enhance drug absorption:
➢ It thickens the tear film, reduces drainage and increase corneal
contact time and ocular bioavailability
➢ The increased volume acts as a reservoir for the drug so that it is re-
spread in the tear film over the cornea with each blink
243
Ophthalmic DD: Excipients
Why?
• For suspensions, the increased viscosity retards the settling of
particles between uses and maintains their suspension for uniform
dosing.
• Polymer solutions have a lubricating effect (by forming a thicker and
uniform precorneal tear film), functioning as OTC ocular
lubricants/artificial tears (dry eye conditions).
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Salma E. EL-Habashy
