Stability testing protocol for herbal products in a detailed review.It’s the ability of formulation to retain its physical, chemical, microbiological and toxicological parameter same as that time of manufacture . Drug product remains within specifications established to ensure its identity, strength, quality and purity. Stability – Chemical and Physical integrity of herbal medicinal products. Over a given time period and under the influence of environmental factors including temperature, humidity and light. To provide evidence on how the quality of active substance varies with time and environmental factors To establish re- test period for active substance To establish shelf life of finished products. To recommend storage conditions. To evaluate the efficacy of drug. To develop suitable packing information for drug product To submit stability information for regulatory agencies. 1.Physical stability study:- The original physical properties namely appearance, uniformity, palatability, dissolution, and suspend ability are maintained. Chemical stability study:- Each and every active ingredient retains its chemical integrity as well as potency specified on label, within the specified limits. It involves drug assay and determination of drug degradation.

1. STABILITY TESTING OF
HERBAL NATURAL
PRODUCTS AND ITS
PROTOCOL
S.GOWTHAMRAJ M.PHARM.,
Department of Pharmacognosy
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2. CONTENTS
 Definition
 Objective
 Types of stability Studies
 Challenges in testing HMPs and steps to overcome it
 Types of stability Testing
 Stability testing Protocol
 Reference
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3. DEFINITIONS
 It’s the ability of formulation to retain its physical, chemical,
microbiological and toxicological parameter same as that time of
manufacture .
 Drug product remains within specifications established to ensure its identity,
strength, quality and purity.
 Stability – Chemical and Physical integrity of herbal medicinal products.
 Over a given time period and under the influence of environmental factors
including temperature, humidity and light.
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4. OBJECTIVE
 To provide evidence on how the quality of active substance varies with time
and environmental factors
 To establish re- test period for active substance
 To establish shelf life of finished products.
 To recommend storage conditions.
 To evaluate the efficacy of drug.
 To develop suitable packing information for drug product
 To submit stability information for regulatory agencies.
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5. TYPES OF STABILITY STUDY
1.Physical stability study:-
The original physical properties namely appearance, uniformity, palatability,
dissolution, and suspend ability are maintained.
2. Chemical stability study:-
Each and every active ingredient retains its chemical integrity as well as
potency specified on label, within the specified limits.
It involves drug assay and determination of drug degradation.
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6. 3. Microbiological stability study:-
Sterility or resistance to microbial growth is maintained as per
the specified requirements.
4. Therapeutic stability study:-
The therapeutic effect remains unaltered.
5. Toxicological stability study:-
No valid increase in toxicity should occurs.
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7. MATERIAL USED FOR STABILITY STUDIES:
1.Active Pharmaceutical ingredient (API)
2.Finished pharmaceutical products
Stages in stability testing:-
• Preformulation
• Final product
• Post marketing
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8. CHALLENGES IN STABILITY TESTING OF
HERBAL MEDICINAL PRODUCTS(HMP):
 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.
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9. STEPS TO OVERCOME CHALLENGES:
1. Use of markers for the HMPs.
 Marker concentration should be within ±5%
 When marker concentration is less in finished product then variation of
±10%
2. Use of fingerprint chromatograms.
3. Use of GCMS, HPTLC, HPLC and spectroscopic technique.
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10. INTRODUCTION:
 Working Party on Herbal Medicinal Products (WPHMP) of the European Agency
for the Evaluation of Medicinal products (EMEA) suggests guidelines on herbal
stability testing.
Climatic Zones for Stability Testing:-
For stability testing purpose, the whole world has been divided into four zones
depending upon the environmental conditions
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11. EMEA GUIDELINE FOR HERBAL PRODUCTS
INCLUDE FOLLOWING FACTS:
 The hygroscopic nature of extracts powder lead to flow-ability and
compressibility problems.
 Higher moisture content can lead greater risk of cohesion and adhesion.
 The presence of variety of photochemical like alkaloids, glycoside, phenolic,
terpenoids and steroids makes botanical chemically complex and pose
challenge for analytical method development.
 Presence of enzyme like glycosidase , esterases or oxidases play important role
in breakdown of plant secondary metabolites. 11

12. STABILITY OF THE NATURAL PRODUCTS (EMEA)
 Stress testing substance
 Accelerated stability testing
 Long term stability testing products
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13. STRESS TESTING:
 Helps to identify the degradation products.
 Further help establish the degradation pathways and the intrinsic
stability of the molecule and validate the stability indicating power of
the analytical procedures used.
 Nature of Stress testing depends on the individual drug substance and the
type of drug product involved.
 Generally conducted on a single batch of the drug substance
The condition include 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.
 Perform phytochemical analysis for constitutes in given sample of
HMPs by HPLC, HPTLC. 13

14. ACCELERATED STABILITY TEST:
 The substance or medicinal product is challenged by a controlled exaggerated
stress (storage conditions) over a short time, so that the rate of degradation
reaction is enhanced.
 In short period time, stability data can be obtained (3 – 6 months)
 Samples are stored at 400C ± 20C; 75 % ± 5 % RH for a period of 6 months.
Procedure:
1. Note down Description, identification, ph, viscosity, assay, heavy metals &
microbial purity.
2. Above parameter should match those specified in monographs or label.
3. Transfer HMPs
a). PET Bottle with Al- cap, containing Rubber cork
b). Glass Bottle withAl- cap, containing Rubber cork.
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15. 4.1st set
1. - 25°C ± 2°C / 60% RH ± 5% --------> Control condition
5.2nd set
- 40°C ± 2°C / 75% RH ± 5% -------> Accelerated condition
6.Carry out sampling at various intervals( 0 ,1, 3, 4 ,5,………months)
7.Perform phytochemical analysis for constitutes in given sample of HMPs by HPLC,
HPTLC.
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16. 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.
STORAGE OF STABILITY SAMPLES:
STUDY Temperature Relative
Humidity
Time period
General 25°C ± 2°C 60% RH ± 5% 12 months
General 30°C ± 2°C 65% RH ± 5% 12 months
Refrigerator 5°C ± 3°C ------ 12 months
Freezer -20°C ± 3°C ------ 12 months
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17. STABILITY SAMPLES TESTING FREQUENCY:
Category Selection of Batches Frequency of Testing
New Drug Product 1st 3 Batch 3,6,9,12,18,24,36
months
& 1 year after expiry
Subsequent Batches 1 Batch every year 6,9,12,18,24,36
months
& 1 year after expiry
Product with primary
change in packing
3 Batch 3, 6,9,12,18,24,36
months
& 1 year after expiry
Product with
secondary change in
packing
3 Batch 3, 6,9,12,18,24,36
months
& 1 year after expiry
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18. PROTOCOL FOR STABILITY TESTING
Protocol is a document describing the basic components of a well controlled
stability study.
A well-planned stability protocol should contain the following information:
1. 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
2. Test attributes - The tests that monitor the quality, potency, purity,
and identity that are expected to vary upon storage are chosen as
stability tests
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19. 3.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
4. 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
5. Storage conditions - These are based upon the marketing climatic zone
of the drug.
Storage condition such that thermal stability as well sensitivity to moisture
can be tested.
STUDY Temperature Relative
Humidity
Time period
General 25°C ± 2°C 60% RH ± 5% 12 months
General 30°C ± 2°C 65% RH ± 5% 12 months
Refrigerator 5°C ± 3°C ------ 12 months
Freezer
Long Term -20°C ± 3°C ------ 12 months 19

20. 6. Storage period –
It generally extend from 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.
7. Testing frequency –
It should be sufficient to establish the stability profile of the
drug Test schedules for different types of stability testing.
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21. 8. Sampling plan - It involves devising for the number of samples to be placed
in the stability chambers and taking out of the charged batch so as to cover the
entire study.
9. 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.
10. Evaluation - The data on quantitative attribute is analysed to determine the
time duration at which 95% one-sided confidence limit for the mean curve
intersects the acceptance criterion.
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22. 11. 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 specification should match as those
mentioned by regulatory authority.
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23. “The Success of your presentation will be judged not by the knowledge
you send but by what the listener receives.”
- Lilly Walters.
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