Overview
ISO 22467:2021 - Traditional Chinese medicine - Determination of microorganisms in natural products - specifies microbiological test methods for natural products used in Traditional Chinese Medicine (TCM). It covers testing of raw materials, herbal pieces and finished preparations to detect and enumerate microorganisms, and to assess product sterility under defined laboratory conditions.
Key topics and technical requirements
- Scope and applicability: Applies only to natural products used in TCM (raw materials, herbal pieces, preparations).
- Test methods: Detailed procedures for
- Test for sterility (aseptic technique, culture media, incubation)
- Microbial enumeration tests (total aerobic microbial count - TAMC, total combined yeast and mould count - TYMC)
- Tests for specified microorganisms (presence/absence of pathogens)
- Culture media and incubation: Recommended media include fluid thioglycollate medium (primarily for anaerobes; incubate 30–35 °C) and soya‑bean casein digest medium (for fungi and aerobes). For products with mercurial preservatives validated alternatives at 20–25 °C are allowed.
- Growth promotion and method suitability: Each lot of medium requires growth promotion testing using specified standard strains (examples listed in Table 1: Escherichia coli ATCC 8739, Pseudomonas aeruginosa ATCC 9027, Staphylococcus aureus ATCC 6538, Candida albicans ATCC 10231, Aspergillus brasiliensis ATCC 16404, etc.). Inocula for growth promotion are small (≤100 cfu); incubation up to 3 days for bacteria and up to 5 days for fungi.
- Controls and quality assurance: Use of seed‑lot systems for strain maintenance, negative controls, method suitability tests, and ongoing environmental monitoring.
- Acceptance criteria: Defined acceptance criteria for sterility tests, enumeration methods and tests for specified microorganisms are provided (see Clause 6 and Annex A for microbiological quality guidance).
- Annexes: Annex A (normative) on microbiological quality; Annex B (informative) with recommended solutions and culture media.
Applications and intended users
ISO 22467:2021 is intended for:
- Quality control laboratories performing microbiological testing of TCM raw materials and products
- Manufacturers of herbal medicines and TCM preparations for in‑house release testing and supplier qualification
- Regulatory authorities and inspectors assessing compliance with microbial safety requirements
- Research laboratories developing validated test methods for herbal product safety
Using ISO 22467 helps harmonize microbial testing for TCM, supports international trade, and provides standardized methods for sterility, microbial enumeration and pathogen testing.
Related standards and references
- Prepared by ISO/TC 249 (Traditional Chinese medicine).
- Sterility definition aligned with ISO 11139:2018 terminology.
- The standard complements national pharmacopeial microbial limits (e.g., those in various national pharmacopeias) by providing harmonized methods for detection and enumeration.
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