Understanding the Options

Ophthalmic Solutions

Prefiltration

• Reduce particles and bioburden
• Extend the life of final filters
• Must be robust for high volume processes
• Run efficiently for optimal process economics

Recommended Filter

Filter Characteristics

Double-layer Polysep II Filters (Grade W6, 1 µm + 0.5 µm) Cartridge Filters Opticap Capsule Filters Optiscale Capsule Filters

Borosilicate glass top layer enhances particle and loading capacity in high solute applications Mixed esters of cellulose membrane bottom layer ensures high retention and filtrate quality Robust construction validated to withstand multiple SIP or hot water sanitization cycles Non-fiber releasing structure preserves product purity 100% integrity tested to ensure quality Available in a variety of pore sizes to accommodate the needs of each user. Grade W6 is commonly used in this application. Choice should be made based on small-scale testing.

Sterile Filtration

• Sterilizing-grade filter to remove microorganisms
• Operate consistently at high flow rates
• Must be robust for high volume processes
• Run efficiently to ensure process economics

Recommended Filter	Filter Characteristics
Charged Durapore 0.22 µm Filters Cartridge Filters Optiseal Cartridges	Sterilizing-grade PVDF membrane Ideal solution when preservative binding is a concern High flow rates and throughput, low extractables and protein binding 100% Integrity testing to ensure performance
Millipore Express SHF 0.2 µm Filters Cartridge Filters Opticap Capsule Filters Optiscale Capsules	Sterilizing-grade PES membrane providing broad chemical compatibility across a wide pH range (1–14) Asymmetric pore structure delivers extremely high flow rates at low preservative binding 100% integrity tested to ensure quality