Stability testing of herbal products involves subjecting samples to various conditions like heat, light, and humidity to determine shelf life and ensure quality over time. Key aspects of stability testing include establishing acceptance criteria and storage conditions, conducting both accelerated and long-term real-time tests, and developing a protocol that specifies test attributes, analytical methods, sampling plans, and evaluation procedures. Challenges with testing herbal products relate to their complex compositions, but can be addressed through marker analyses and fingerprinting techniques. Proper stability testing is important for determining appropriate packaging, storage, and expiry dates.

1. INDUSTRIAL PHARMACOGNOSTICALTECHNOLOGY
STABILITY TESTING OF HERBAL NATURAL
PRODUCTS AND THEIR PROTOCOL
Presented By : Tejaswini C

2.  Stability test- A series of tests designed to obtain information on
the stability of a natural product in order to define its shelf-life
and utilization period under specified packaging and storage
conditions.
 Shelf life- It is the period of time during which a drug product if
stored correctly, is expected to comply with the specification as
determined by stability studies on a number of batches of the
product.
The shelf-life is used to establish the expiry date of each batch.
STABILITY TESTING

3. Factors affecting stability:
 Light
 Temperature
 Moisture
 Hydrolysis
 Oxidation
 Polymerization
 Geometric isomerization

4. Why stability testing is important:
 Shelf-Life Determination: Stability testing studies shows how long this product
can be stored at normal and accelerated conditions without any degradation.
 Storage Condition Recommendation:In the stability testing lab, storage
conditions and changes in the substances are recorded
 Elimination of Impurities: In stability testing, each ingredient has been
analysed under various environmental factors. So, it becomes easy to identify
and eliminate any impurities that may be formed during the shelf life of the
product.

5.  Product Development: . This testing helps to assess the physical,
chemical, and therapeutic stability of a product..
 Ensures Quality:Stability testing assures the purity of ingredients and
the quality of the final product. The stability report ensures that the
pharmaceutical product is fit for human consumption.
 Packaging Material Selection: . The packaging should maintain the
quality of the product during transportation and storage.
 Legal Approvals: Stability testing of the natural products is required
for regulatory approvals

6. Adverse effects of instability
Loss of active constituents
Loss of vehicle or excipients
Loss of content uniformity
Loss of elegance
Reduction in bioavailability
Production of potential toxic material

7. Stability studies are mainly done on
 Active pharmaceutical ingredient
 Finished product
Stability testing done in:
 Preformulation
 Final product
 Post-marketing

8. Types of stability studies:
☻ Physical Stability: With the stability test, changes are monitored in the physical attributes of the
drug when stored for specified durations
☻ Chemical Stability : each and every active ingredient should retains its chemical integrity as well as
potency specified on the label
☻ Microbial Stability : Any presence of pathogenic microorganisms and the effectiveness of added
microbial preservatives and any impact on the efficiency of the drug are monitored in microbial
stability studies of drugs.
☻ Therapeutical stability studies: where the therapeutic effect of the drug should remain unaltered till
its shelf life
☻ Toxicological stability studies: no toxicity should occur till its shelf life.

9. EMA GUIDELINES FOR HERBAL PRODUCTS INCLUDE THE FOLLOWING
FACTS:
 The hygroscopic nature of extracts powder lead to flow-ability and compressibility
problems.
 Higher moisture content can lead to the greater risk of cohesion and adhesion.
 The presence of a variety of phytochemical compounds like alkaloids, glycoside,
phenolic, terpenoids and steroids makes botanical chemically complex and poses
challenges for analytical method development
 The presence of enzyme-like glycosidase, esterase or oxidases play important role in
the breakdown of plant secondary metabolites.

10. Stability studies Methods:
 Accelerated Testing: Product subjected to high temperature, humidity. light, etc.
40°C/ 75% RH. At 3rd and 6th month.
 Real Time (long term) Testing: Longer duration. 25-30°C & 35- 75%
RH(depending on climatic zone), for 3rd, 6th, 9th, 12th, 18th, 24th, and 36th
month
 Intermediate Testing: Conducted when accelerated studies fail. At 25°C for
longer duration of time
 Stress Testing: Includes effects of temperature, i.e., above 40°C and 275% RH
 Forced Degradation Testing: Performed to provide intrinsic stability assessment
of drug

11. Climatic Zones for Stability Testing:
For stability testing purposes, the whole world has been divided into four zones
depending on the environmental

12. STRESS TESTING: -
 Further help establish the degradation pathways and the intrinsic stability of the molecule
and validate the Stability-indicating power of the analytical procedures used
 The nature of Stress testing depends on the individual drug substances and type of the drug
involved
The condition includes the effect
 Temperatures (in 10°C increments (e.g., 50°C, 60°C, etc.) above that for accelerated
testing)
 Humidity (e.g., 75% RH or greater) where appropriate, oxidation, and photolysis on the
drug substance.
 The testing should also evaluate the susceptibility of the drug substance to hydrolysis
across a wide range of pH values when in solution or suspension.

13. ACCELERATED STABILITY TESTS:
The substance or medicinal product is challenged by controlled exaggerated stress (storage conditions) over a short time so
that the rate of degradation reaction is enhanced. In a short period of time, stability data can be obtained (3-6 months)
Samples are stored at 40°C ± 2°C; 75 % ± 5% RH for a period of 6 months
Procedure:
 Note down Description, identification, ph., viscosity, assay, heavy metals & microbial purity.
 The above parameter should match those specified in monographs or labels.
 Transfer HMPs
a). PET Bottle with Al- cap, containing Rubber cork
b). Glass Bottle with Al- cap, containing Rubber cork.
 1st set -25°C 2°C / 60% RH ± 5%--------> Control condition
 2nd set 40°C 2°C / 75% RH ± 5%-------> Accelerated condition
 Carry out sampling at various intervals ( 0,1, 3,4,5,......... months)

14. LONG-TERM STABILITY TESTING:
Evaluation of the physical, chemical and microbiological characteristics of a drug product over the
expected duration of shelf-life under recommended storage conditions and in the proposed
container/closure system.

16. Challenges in Stability testing of Herbal medicinal products :
 HMPs are complex in nature due to their high number of
constituents.
 Constituents belong to different chemical classes with
different analytical behaviour.
 Constituents sometimes have very low concentrations in the
finished product.
 Different requirements for the different types of extracts.

17. Steps to overcome challenges:
 Use of markers for the HMPs.
 Marker concentration should be within ±5%
 When marker concentration is less in the finished product than a
variation of ±10%
 Use of fingerprint chromatograms GCMS, HPTLC, HPLC and
spectroscopic technique.

18. PROTOCOL FOR STABILITY TESTING
A protocol is a document describing the basic components of a well-controlled stability
study. A well-planned stability protocol should contain the following information:
 Selection of batches and samples: In general, this selection should constitute a
random sample from pilot or production batches that may involve a single batch or 2-3
batches
 Test attributes The tests that monitor the quality, potency, purity, and identity that are
expected to vary upon storage are chosen as stability tests
 Analytical procedures - Procedures given in the official compendia should be
followed and if alternate methods are to be used, they need to be duly validated

19. • Acceptance criteria; This should be fixed beforehand in the form of statistical limits for the
results manifested in computable terms and pass or fail for qualitative tests
• Storage conditions - These are based upon the marketing
• Storage period – It generally extends from a minimum of 3 or 6 months in accelerated and
stress testing and up to 12, 18, or 60 months in ongoing or follow-up stability testing.

20. • Frequency - It should be sufficient to establish the stability profile
of the drug Test schedules for different types of stability testing.

21. • Sampling plan - It involves devising the number of samples to be placed in the stability chambers and
taken out of the charged batch so as to cover the entire study.
• Container closure system - The testing in actual containers as well as closures scheduled for marketing,
are to be tested separately with proper orientation of storage of containers.
• Evaluation - The data on quantitative attributes is analysed to determine the time duration at which 95%
one-sided confidence limit for the mean curve intersects the acceptance criterion.
• Statements, labelling - A storage statement, retest period, and re-test date based on the stability evaluation
of the drug substance should be established for the labelling. Labelling specifications should match those
mentioned by a regulatory authority.

22. REFERENCE:
1. Guideline on quality of herbal medicinal products / traditional herbal medicinal products
(CPMP/QWP/2819/00, Rev 1)
2. Guideline on Quality of Combination Herbal Medicinal Products / Traditional Herbal Medicinal
Products (Doc. Ref. EMEA/HMPC/CVMP/214869/2006)
3. Guideline on specifications: test procedures and acceptance criteria for herbal substances, herbal
preparations and herbal medicinal products/traditional herbal medicinal products
(CPMP/QWP/2820/00, EMEA/CVMP/815/00)
4. ICH Guidelines Stability Testing of New Drug Substances and Products (CPMP/ICH/2736/990)
5. Roth-Ehrang, Asche, Hubbert, Kruse, Lutz-Röder, Poetsch, Tegtmeier, Wiedemann and Steinhoff:
Stability Testing of Herbal Medicinal Products.