USP <789> - Particulate Matter in Ophthalmic Solutions

What it says

General Chapter <789> describes particulate matter testing methodology specific to ophthalmic solutions, using light obscuration or microscopic particle count methods adapted for the smaller sample volumes and specific formulation characteristics typical of ophthalmic products, with acceptance criteria appropriate to this route of administration.

Paraphrased for plain-language clarity. Always verify against the current published regulation text.

What it means in practice

• Ophthalmic products present distinct testing challenges compared to injectable products, particularly given typically smaller container fill volumes, requiring method adaptations from the general injectable particulate matter approach described in Chapter <788>.
• Particulate matter in ophthalmic products carries genuine patient risk given direct ocular administration, connecting to the same underlying patient safety rationale as injectable particulate control, adapted for this specific route of administration and its own risk profile.
• Ophthalmic formulation characteristics, including viscosity modifiers commonly used in these products, can present similar method interference challenges to those seen with certain injectable products, requiring appropriate method validation for the specific formulation.

What inspectors look for

• Whether particulate matter test methodology is appropriately adapted and validated for the specific ophthalmic product's fill volume and formulation characteristics.
• Whether particulate matter specifications are appropriate for ophthalmic administration specifically, rather than simply borrowed from injectable product acceptance criteria without adaptation.
• Whether particulate matter excursions are investigated with the same root cause rigor applied to other quality testing failures.

Related regulations