Analytical Methods for Phytomedicine
The Society for Integrative Phytomedicine (SIPM) is an international organization dedicated to the development of standards for phytomedicine, medicinal fungi, and related natural health products. The work of preparing SIPM Standards is carried out through technical committees composed of experts from academia, industry, regulatory bodies, and healthcare practice.
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This document was prepared by Technical Committee TC 4, Analytical Methods.
This is the first edition of SIPM 0300.
A list of all parts in the SIPM 0300 series can be found on the SIPM website.
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1. Introduction
The quality and safety of phytomedicine products depend on reliable analytical methods for identity verification, purity assessment, and potency determination. Unlike conventional pharmaceuticals, phytomedicines present unique analytical challenges due to their complex chemical composition and natural variability.
This document establishes general requirements for analytical methods used in the quality control of phytomedicine products. It provides a framework for method selection, validation, and application that ensures reliable and reproducible results across laboratories and jurisdictions.
The standard addresses three fundamental aspects of phytomedicine analysis:
Identity: Confirming that the material is what it purports to be
Purity: Ensuring the material is free from unacceptable contamination
Potency: Determining the concentration of active or marker constituents
This document is intended to be used in conjunction with specific analytical method standards in the SIPM-0300 series, which provide detailed procedures for particular tests and analytes.
2. Scope
This document specifies general requirements for analytical methods used in the quality control of phytomedicine products.
It is applicable to:
Identity testing of plant materials and extracts
Purity testing for contaminants and impurities
Potency determination for active or marker constituents
Method validation and verification
Documentation and reporting of analytical results
This document covers:
Herbal substances and preparations
Medicinal fungi materials and products
Finished phytomedicine products
This document does not cover:
Specific analytical procedures for individual compounds or matrices
Microbiological testing methods
Clinical laboratory methods
Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
3. Terms and definitions
For the purposes of this document, the following terms and definitions apply. Terms defined in SIPM-0001 also apply where relevant.
3.1. analytical procedure
detailed description of the steps required to perform an analytical test
Note | Analytical procedures include sample preparation, measurement, and calculation steps. |
3.2. method validation
process of demonstrating that an analytical procedure is suitable for its intended purpose
3.3. specificity
alt:[selectivity]
ability of an analytical procedure to assess unequivocally the analyte in the presence of components that may be expected to be present
3.4. accuracy
alt:[trueness]
closeness of agreement between the value found and the value accepted as true
3.5. precision
closeness of agreement between a series of measurements obtained from multiple sampling of the same homogeneous sample under prescribed conditions
3.6. repeatability
precision under the same operating conditions over a short interval of time
3.7. intermediate precision
precision within-laboratory variations, such as different days, different analysts, different equipment
3.8. reproducibility
precision between laboratories
3.9. limit of detection
alt:[LOD]
lowest amount of analyte that can be detected but not necessarily quantified
3.10. limit of quantitation
alt:[LOQ]
lowest amount of analyte that can be quantitatively determined with suitable precision and accuracy
3.11. linearity
ability of an analytical procedure to obtain test results that are directly proportional to the concentration of analyte within a given range
3.12. range
interval between upper and lower concentration amounts of analyte for which the analytical procedure has suitable precision, accuracy, and linearity
3.13. robustness
capacity of an analytical procedure to remain unaffected by small, but deliberate variations in method parameters
3.14. reference standard
substance or material characterized for use as a measurement standard in analytical procedures
Note | Reference standards may be primary standards or working standards. |
3.15. system suitability
evaluation of the components of an analytical system to ensure that the system is operating within acceptable parameters before analysis
| Parameter | Identity tests | Quantitative tests |
|---|---|---|
Specificity | Required | Required |
Accuracy | Not applicable | Required |
Precision (repeatability) | Not applicable | Required |
Intermediate precision | Not applicable | Required |
Linearity | Not applicable | Required |
Range | Not applicable | Required |
LOD | Not applicable | When relevant |
LOQ | Not applicable | Required |
Robustness | Recommended | Required |
4. Identity testing
4.1. General requirements
Identity testing shall be performed to confirm that plant material or preparations are authentic and correctly identified.
4.2. Methods of identity testing
4.2.1. Macroscopic examination
Macroscopic examination shall include:
Visual assessment of color, form, and texture
Odor assessment (where appropriate)
Comparison with authenticated reference material or written description
4.2.2. Microscopic examination
Microscopic examination shall include:
Observation of characteristic cellular structures
Comparison with reference material or photomicrographs
Documentation of distinguishing features
Note | Microscopic examination is particularly important for powdered materials. |
4.2.3. Chromatographic methods
Chromatographic methods for identity testing shall:
Produce a fingerprint characteristic of the species
Include comparison with authenticated reference material
Document retention times and peak patterns
Acceptable chromatographic methods include:
Thin-layer chromatography (TLC)
High-performance liquid chromatography (HPLC)
Gas chromatography (GC)
4.2.4. Spectroscopic methods
Spectroscopic methods may be used for identity testing, including:
Near-infrared spectroscopy (NIR)
Fourier-transform infrared spectroscopy (FTIR)
Nuclear magnetic resonance (NMR)
4.2.5. DNA-based methods
DNA-based authentication shall:
Use validated marker regions appropriate for the species
Include appropriate positive and negative controls
Be performed by competent laboratories
4.3. Acceptance criteria
Material shall be considered positively identified when:
a) Results of identity testing are consistent with reference material or documented characteristics b) No evidence of adulteration or substitution is detected c) Testing is performed by qualified personnel using validated methods
5. Purity testing
5.1. General requirements
Purity testing shall be performed to ensure that plant materials and preparations are free from unacceptable levels of contaminants.
5.2. Contaminant categories
5.2.1. Foreign matter
Testing for foreign matter shall address:
Other plant species
Plant parts other than the intended part
Inert materials (soil, stones, etc.)
Acceptance criteria shall be specified based on pharmacopoeial standards or product specifications.
5.2.2. Heavy metals
Heavy metal testing shall include, at minimum:
Lead (Pb)
Cadmium (Cd)
Mercury (Hg)
Arsenic (As)
Acceptance limits shall be established based on regulatory requirements or risk assessment.
5.2.3. Pesticide residues
Pesticide residue testing shall:
Include pesticides commonly used in cultivation of the species
Consider pesticides from previous land use
Comply with regulatory limits for the intended market
5.2.4. Mycotoxins
Mycotoxin testing shall be performed when:
Material is susceptible to fungal contamination
Storage conditions may promote fungal growth
Regulatory requirements apply
Common mycotoxins to be tested include:
Aflatoxins (B1, B2, G1, G2)
Ochratoxin A
Fumonisins
5.2.5. Microbiological contamination
Microbiological testing shall address:
Total aerobic microbial count
Yeast and mold count
Specified pathogenic organisms
Acceptance criteria shall be based on intended use and regulatory requirements.
5.2.6. Solvent residues
For extracts prepared using organic solvents, testing shall verify that residual solvent levels are within acceptable limits.
| Contaminant | Test method | Acceptance criteria |
|---|---|---|
Foreign matter | Visual/manual separation | Pharmacopoeial limits |
Heavy metals | ICP-MS, AAS | ICH Q3D limits |
Pesticides | GC-MS, LC-MS | Regulatory limits |
Mycotoxins | HPLC, LC-MS | Regulatory limits |
Microbiology | Plate count, PCR | Pharmacopoeial limits |
6. Potency determination
6.1. General requirements
Potency determination quantifies the concentration of active constituents or marker compounds in plant materials and preparations.
6.2. Analyte selection
6.2.1. Active constituents
When known active constituents are identified:
Quantification of active constituents is preferred
Multiple actives may be quantified when relevant to efficacy
Bioactive fractions may be quantified as a group
6.2.2. Marker compounds
When active constituents are not fully characterized:
Characteristic or analytical markers may be used
The relationship between markers and activity shall be documented
Selection of markers shall be scientifically justified
6.3. Quantitative methods
6.3.1. Chromatographic methods
Chromatographic methods for potency determination shall:
Be validated for specificity, accuracy, precision, linearity, and range
Use reference standards of known purity
Include system suitability tests
6.3.2. Spectrophotometric methods
Spectrophotometric methods may be used when:
Chromatographic methods are not practical
The analyte or analyte group has characteristic absorption
Interference from other components has been evaluated
6.4. Specifications
Acceptance criteria for potency shall be established based on:
Historical data for the species
Phytochemical variability
Clinical or traditional use information
Manufacturing requirements
| Parameter | Acceptance criteria |
|---|---|
Marker compound A | NLT 2.0% and NMT 4.0% (dry basis) |
Marker compound B | NLT 0.5% (dry basis) |
Total phenolics (as gallic acid) | NLT 5.0% (dry basis) |
7. Method validation
7.1. Validation requirements
Analytical methods shall be validated before use in quality control testing. Validation shall be documented and shall demonstrate that the method is fit for its intended purpose.
7.2. Validation parameters
Validation shall address the parameters specified in Method validation parameters by test type, as applicable to the method type.
7.3. Validation protocol
A validation protocol shall be prepared that includes:
Objective of the validation
Description of the analytical procedure
Parameters to be evaluated
Acceptance criteria for each parameter
Experimental design and sample requirements
7.4. Validation report
A validation report shall be prepared that includes:
Summary of validation experiments performed
Raw data and statistical analysis
Comparison of results to acceptance criteria
Conclusion on method suitability
Any deviations from the protocol and their impact
7.5. Revalidation
Methods shall be revalidated when:
Changes are made to the analytical procedure
The method is transferred to another laboratory
Results indicate the method is no longer performing adequately
7.6. Stability testing
Stability testing shall be conducted to establish shelf-life specifications for botanical materials and finished products.
Note | Stability testing for botanical products shall follow ICH Q1 guidelines adapted for the unique characteristics of plant-based materials [ICH Q1 Stability Testing of Drug Substances and Drug Products]. |
7.6.1. Storage conditions
Long-term and accelerated stability studies shall be conducted under the following conditions:
| Study type | Temperature | Humidity | Duration |
|---|---|---|---|
Long-term (Zone I/II) | 25 deg C ± 2 deg C | 60% RH ± 5% RH | 24-36 months |
Long-term (Zone III/IVa) | 30 deg C ± 2 deg C | 65% RH ± 5% RH | 24-36 months |
Long-term (Zone IVb) | 30 deg C ± 2 deg C | 75% RH ± 5% RH | 24-36 months |
Accelerated | 40 deg C ± 2 deg C | 75% RH ± 5% RH | 6 months |
Intermediate (if accelerated fails) | 30 deg C ± 2 deg C | 65% RH ± 5% RH | 12 months |
7.6.2. Testing intervals
Samples shall be tested at the following intervals:
Long-term studies: 0, 3, 6, 9, 12, 18, 24, and 36 months
Accelerated studies: 0, 3, and 6 months
Additional timepoints as needed to characterize degradation profile
7.6.3. Stability-indicating methods
Stability-indicating methods shall:
Demonstrate specificity for marker compounds and potential degradation products
Detect changes in active constituent concentrations
Quantify degradation products when applicable
Be validated according to ICH Q2(R1) requirements
| Parameter | Assessment method |
|---|---|
Marker compound content | HPLC, UPLC quantification of characteristic compounds |
Degradation products | HPLC-DAD, LC-MS detection of degradation markers |
Physical appearance | Color, odor, texture assessment; spectrophotometric analysis |
Moisture content | Loss on drying (LOD), Karl Fischer titration |
Microbiological quality | Total aerobic count, yeast/mold, specified pathogens |
Heavy metals | ICP-MS, AAS for elemental contaminants |
7.6.4. Shelf-life extrapolation
Shelf-life may be extrapolated from accelerated data according to the following principles:
If accelerated data show no significant change: Shelf-life may be extrapolated to twice the accelerated period, not exceeding 36 months
If significant change occurs at accelerated conditions: Intermediate conditions data shall be used; shelf-life extrapolation limited
Statistical analysis (e.g., linear regression at 95% confidence) shall support shelf-life claims
[ICH Q1 Stability Testing of Drug Substances and Drug Products] (ICH stability testing guidelines)
7.7. Method transfer
When analytical methods are transferred between laboratories, the receiving laboratory shall demonstrate equivalence through method transfer studies.
7.7.1. Transfer approaches
The following method transfer approaches are acceptable:
| Parameter | Acceptance criteria |
|---|---|
Assay (marker compounds) | Results within ±2% of originating laboratory mean; or combined RSD ≤2% |
Related substances | Results within ±10% relative or ±0.1% absolute (whichever is greater) |
Dissolution | Results within ±5% of originating laboratory mean at each timepoint |
Identification tests | 100% agreement in qualitative results |
7.7.2. Transfer protocol requirements
Method transfer protocols shall include:
Description of the method and critical parameters
Reference materials and samples to be analyzed
Number of replicates and analysts
Acceptance criteria with statistical justification
Documentation requirements
8. Reporting of results
8.1. Certificate of analysis
A certificate of analysis shall be provided for each batch tested, including:
Identity of the material tested
Batch or lot number
Date of testing
Reference to test methods used
Test results with units
Acceptance criteria
Pass/fail determination
Name and signature of authorized person
8.2. Expression of results
Results shall be expressed:
In appropriate units (e.g., % w/w, mg/g, ppm)
On a consistent basis (dry weight or as-is)
With appropriate significant figures
With measurement uncertainty when required
8.3. Record retention
Analytical records shall be retained for a period defined by:
Regulatory requirements
Product shelf life
Quality management system requirements
Note | A minimum retention period of one year beyond product shelf life is recommended. |
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