USP <232> and <233> - Elemental Impurities - Limits and Procedures

What it says

General Chapter <232> establishes permitted daily exposure limits for elemental impurities by route of administration, while General Chapter <233> describes analytical procedures, typically inductively coupled plasma methods, for determining elemental impurity levels, together forming the USP framework closely aligned with ICH Q3D(R2).

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

What it means in practice

• Chapter <232> provides the limits while Chapter <233> provides the analytical methodology to test against those limits, and both chapters are typically applied together as a pair, similar to how <1225> and <1226> work together for method validation and verification.
• This USP framework is closely harmonised with ICH Q3D(R2), reflecting the same underlying risk-based, route-specific approach to elemental impurity control.
• Analytical method validation for the specific elemental impurity test method used must itself be demonstrated, consistent with general analytical method validation expectations under ICH Q2(R2).

What inspectors look for

• Whether elemental impurity testing limits applied match the correct route of administration for the specific product.
• Whether the analytical method used for elemental impurity testing has documented validation data supporting its use for the specific product matrix.
• Whether the elemental impurity risk assessment and the actual testing programme are connected, with testing genuinely covering the elements identified as plausible risks.

Related regulations