Page 119 - Pharmaceutics IV (02-06-01305)
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Ophthalmic DD: Excipients
Considerations for preservatives selection:
• The borate buffer system has good antimicrobial properties and can
boost the antimicrobial efficacy of some preservatives.
• Incorporation of viscosity-increasing agents can increase the
irritation potential of a preservative (prolonged ocular retention).
• pH of efficacy: the antimicrobial properties of benzalkonium chloride
decrease whenever the pH of the formulation falls below 5.
• Incorporation of surfactants and polymers that bind the preservative
will decrease antimicrobial efficacy.
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Ophthalmic DD: Excipients
When?
• They are added in multidose preparations.
• They are not added to preparations:
➢ To be used during surgery or in the treatment of traumatized eyes
➢ For intraocular administration
➢ For chronic topical applications (dry eye, glaucoma, …)
Preservative-free products!
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Salma E. EL-Habashy
