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Ophthalmic DD: dosage forms
Semisolid preparations
Gels
• Stimuli-responsive gels/ gel-forming solutions
➢ They are low-viscosity liquids containing polymers that gel on
contact with the tear fluid.
➢ The liquid to gel phase transition can be triggered by different stimuli:
temperature (poloxamer), pH (Carbopol), ions (alginate), …
➢ Advantage over preformed gels: the dose is more reproducible,
and administration is easier, thus improving patient compliance.
267
Ophthalmic DD: dosage forms
Ocular drug delivery systems
• They are ocular drug delivery systems that are applied via
injection/implantation or local application
• They provide:
➢ Localized, controlled drug release over an extended period of
time
➢ Minimized systemic side effects are minimized due (patient
compliance)
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Salma E. EL-Habashy 134
