Pharmaceutical Secondary Reference Standards chemicals

What a secondary standard is

Pharmacopoeias issue primary reference standards, such as USP Reference Standards, EDQM Chemical Reference Substances, BP CRS and IP Reference Standards. They are accepted for their compendial use without further proof, but they are costly and sold in small amounts. A secondary or working standard is a material whose identity and potency have been established against the primary standard. ICH Q7 accepts this approach provided the material is tested against the primary and requalified at set intervals.

What qualification includes

• Identity by IR, NMR, MS or HPLC retention, matching the primary standard.
• Assay against the primary standard to assign a potency.
• Chromatographic purity, water and residual solvents.
• A documented retest or requalification date.

When to choose them

Secondary standards suit routine release testing, stability programmes and in-process control, where large volumes of standard are used. Keep primary standards for qualification and disputes.

Documentation

Each standard ships with a COA stating the primary standard lot used, the assigned value and its basis, with supporting spectra and chromatograms. Browse Impurity Reference Standards.