Page 135 - Pharmaceutics IV (02-06-01305)

Ophthalmic DD: dosage forms

Ointments Semisolid preparations

• Advantages:

❑ Allow the incorporation of poorly soluble and hydrolysable drugs
(Antibiotics, antifungals, steroids, …)

❑ Reduce drainage and prolong corneal residence time (ocular

bioavailability)

❑ Can be entrapped in the conjunctival fornices forming a drug reservoir

❑ Simple formulation: no special excipients needed (pH, osmolarity,

preservatives, …)

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Ophthalmic DD: dosage forms

Ointments Semisolid preparations

• Disadvantages:

➢ More difficult to administer compared to liquid preparations (dose

uniformity!)
➢ Blurring of vision arises which tends to reduce patient compliance

(night-time administration!).
➢ Drug may be entrapped within the ointment base due to favourable

partitioning, inhibiting drug release.

➢ The base is sensitive to changes in temperature

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Salma E. EL-Habashy 132