ISO 5228:2023

Overview - ISO 5228:2023 (Rheum root and rhizome)

ISO 5228:2023 is an international standard from ISO/TC 249 (Traditional Chinese medicine) that defines quality and safety requirements for the dried root and rhizome of three Rheum species: Rheum palmatum, Rheum tanguticum and Rheum officinale. The standard applies to these materials when sold or used as natural medicines in international trade (whole medicinal materials and decoction pieces). It does not cover processing methods or processed products.

Key topics and technical requirements

The standard provides a comprehensive framework for assessing Rheum root and rhizome, including:

• Description and morphology - visual and physical characteristics (examples in the standard include typical piece sizes and external features).
• Identification - macroscopic, microscopic and chemical identification methods to distinguish the three species.
• Chromatographic tests - Thin-layer chromatography (TLC) identification is specified (Annex A).
• Marker compound determination - methods for rhaponticin and other marker compounds (Annex B describes HPLC‑UV procedures).
• Quality limits and tests - requirements and test methods for:
  • Moisture
  • Total ash and acid‑insoluble ash
  • Extractives
  • Heavy metals (referencing ISO 18664)
  • Pesticide residues (referencing ISO 22258)
• Sampling and batch definition - batch defined as samples from the same place/time up to 5 000 kg.
• Packaging, storage, transportation, marking and labelling - requirements to protect quality during trade.
• Informative annexes - include national/regional requirement comparisons and species differentiation.

Practical applications and users

ISO 5228:2023 is intended to support consistent quality, safety and trade of Rheum raw materials. Typical users include:

• Quality control laboratories in herbal and pharmaceutical industries (TLC, HPLC, heavy metal and pesticide testing).
• Regulatory authorities and pharmacopoeia bodies harmonizing import/export requirements.
• Manufacturers and suppliers of Chinese materia medica and decoction pieces ensuring compliance for international markets.
• Customs, procurement and trade compliance teams verifying batches and labels.
• Researchers and formulators requiring validated identification and marker compound methods.

Related standards

ISO 5228 references or aligns with other TCM and analytical standards, such as:

• ISO 18664 (heavy metals)
• ISO 22258 (pesticide residues by GC)
• ISO 21371 (labelling for oral/topical TCM products)
• ISO 22217 (storage requirements)
• ISO 23723 (general requirements for herbal raw material)

ISO 5228:2023 helps harmonize global trade and laboratory practice for Rheum root and rhizome by providing clear identification, testing and safety criteria for these widely used Traditional Chinese medicine materials.