Page 124 - Pharmaceutics IV (02-06-01305)

Ophthalmic DD: Excipients

• Irritation power of surfactants decreases in the following order:
cationic > anionic > non-ionic.

• Nonionic surfactants can remove the mucus layer and disrupt the tight
junction in the cornea. So, the lowest concentration possible is used to
perform the desired function.

• Nonionic surfactants are the most commonly used. Examples include;
polysorbate 20 and 80.

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Viscosity imparting/
thickening agents

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Salma E. EL-Habashy