Stability testing is conducted to provide evidence on how the quality of a drug substance or product varies over time under the influence of environmental factors like temperature and humidity. It helps establish a re-test period or shelf life and recommended storage conditions. Stress testing involves subjecting samples to more extreme conditions to identify potential degradants and validate stability-indicating methods. Protocols specify batches tested, storage conditions, tests conducted, and timepoints. ICH guidelines provide recommendations for stability testing conditions and acceptance criteria.

1. STABILITY
TESTING
1

2.  Stability testing – Definition
Selected Definitions
 Stability testing Protocol
 Stability testing of Drug substances
 Stress testing of Drug substances
 Shelf life determination
ICH Guidelines
2

3. 3
Stability critical quality attribute to ensure safety and efficacy
through out the product shelf life
Stability integral part of product development
The purpose of stability testing is to provide evidence on how
the quality of a drug substance or drug product varies with time
under the influence of a variety of environmental factors such as
temperature, humidity, and light, and to establish a re-test period
for the drug substance or a shelf life for the drug product and
recommended storage conditions

4. Re-test date
The date after which samples of an API should be
examined to ensure that the material is still in compliance
with the specification and thus suitable for use in the
manufacture of a given FPP.
Shelf life (expiration dating period, conformance period)
The time period during which an API or a FPP is expected
to remain within the approved shelf-life specification,
provided that it is stored under the conditions defined on the
container label.
4

5.  Formal stability studies
Long term and accelerated (and intermediate) studies
undertaken on primary and/or commitment batches
according to a prescribed stability protocol to establish or
confirm the re-test period of an API or the shelf life of a
FPP.
 Stress testing – forced degradation (API)
Studies undertaken to elucidate the intrinsic stability of the
API. Such testing is part of the development strategy and
is normally carried out under more severe conditions than
those used for accelerated testing.
 Stress testing – forced degradation (FPP)
Studies undertaken to assess the effect of severe
conditions on the FPP. Such studies include photostability
testing (see ICH Q1B) and compatibility testing on APIs
with each other in FDCs and API(s) with excipients during
formulation development.
5

6.  Primary batch
A batch of an API or FPP used in a formal stability study, from
which stability data are submitted in a registration application for
the purpose of establishing a re-test period or shelf life,
respectively. A primary batch of an API should be at least a pilot
scale batch. For a FPP, two of the three batches should be
atleast pilot scale batch, and the third batch a production batch.
 Commitment batches
Production batches of a drug substance or drug product for
which the stability studies are initiated or completed post
approval through a commitment made in the registration
application.
6

7. 7
 Pilot (scale) batch
A batch of an API or FPP manufactured by a procedure
fully representative of and simulating that to be applied to
a full production scale batch. (For solid oral dosage forms, a pilot
scale is generally, at a minimum, one-tenth that of a full production
scale or 100,000 tablets or capsules, whichever is the larger.)
 Production (scale) batch
A batch of an API or FPP manufactured at production scale
by using production equipment in a production facility as
specified in the application.

8. 8
 Supporting data
Data, other than those from formal stability studies, that
support the analytical procedures, the proposed re-test
period or shelf life, and the label storage statements.
Such data include
(1) Stability data on early synthetic route batches of API,
small-scale batches of materials, investigational
formulations not proposed for marketing, related
formulations, and product presented in containers and
closures other than those proposed for marketing;
(2) Information regarding test results on containers; and
(3) Other scientific rationales.

9. 9
 Specification - Release
The combination of physical, chemical, biological, and
microbiological tests and acceptance criteria that determine the
suitability of a drug product at the time of its release.
 Specification - Shelf life
The combination of physical, chemical, biological, and
microbiological tests and acceptance criteria that determine the
suitability of an API throughout its re-test period, or that anFPP
should meet throughout its shelf life.
 Mass balance
The process of adding together the assay value and levels of
degradation products to see how closely these add up to 100% of
the initial value, with due consideration of the margin of analytical
error.

10. Stability testing Protocol includes:-
1. Batches tested
2. General information
3. Container/closure system
4. Literature and supporting data
5. Stability-indicating analytical methods
6. Testing plan
7. Test parameters
8. Test results
9. Other requirements (post-approval commitments)
10. Conclusions
 Result sheets must bear date and responsible person signature /
QA approval.
10

11. ILLUSTRATIVE DATA OF API STABILITY
BATCHES
11
Batch number
Date of manufacture
Site of manufacture
Batch size (kg)
Primary packing materials
Date of initial analysis
The batches should be representative of the manufacturing process and
should be manufactured from different batches of key intermediates.

12. ILLUSTRATIVE DATA OF FPP:
TABLET/CAPSULE
12
Batch number
Date of manufacture
Site of manufacture
Batch size (kg)
Batch size (number of units)
Primary packing materials
Date of initial analysis
Batch number of the API
The batches should be representative of the manufacturing process and
should be manufactured from different batches of APIs.

13. STABILITY PROTOCOL - API
13
Protocol Parameter Description
Storage conditions (including
tolerances) and testing frequency
25°C/60% RH 0, 3, 6, 9, 12, (18, 24, 36)
months
30oC/75% RH 0, 3, 6, 9,12, (18, 24, 36)
months
40°C/75% RH 0,3,6 months
Batch number and size L40438 (Jan. 2005), 80.50 kg
L50041 (Feb.2005), 69.00 kg
L50054 (March 2005), 73.00 kg
Container closure system(s) Simulated: double PE bags in black PE bag kept
in one-kg fiberboard drums well-closed
Tests and acceptance criteria Assay by(98.0-102.0%), ImpA (NMT 0.15%),
ImpB (NMT0.3%), and so on
Other(s) Stress testing, including photostability testing
according to ICH Q1B

14. Stability protocol FPP– oral
suspension
Protocol Parameter Description
Storage conditions (including
tolerances) and testing
frequency
25°C/60% RH 0, 3, 6, 9, 12, (18, 24, 36) months
30oC/75% RH 0, 3, 6, 9,12, (18, 24, 36) months
40°C/75% RH 0,3,6 months
Batch numbers and size NEV40438 (Jan. 2007), 4000 bottles (960 liters)
NEV50439 (Jan.2007), 4000 bottles (960 liters)
NEV50440 (Jan. 2007), 4000 bottles (960 liters)
Container closure system(s)
proposed for marketing
White HDPE bottle with two piece child-resistant
closure
Tests and acceptance criteria Assay (95.0-105.0%), there are no degradants,
dissolution testing (and profile), in-use stability test,
preservative contents, antimicrobial preservative
effectiveness, re-suspendibility (sedimentation rate)
The batches should be representative of the manufacturing process and should be
manufactured from different batches of APIs. Executed manufacturing records and
certificates of analysis on the above batches should be submitted 14

15. Stability Testing - API
15
Stress testing (forced degradation)
Regulatory stability testing

16. ICH guidelines on stress testing
Standard Title and reference
ICH Q1A(R2) Stability Testing of New Drug Substances and
Products (the parent guideline)
ICH Q1B Photo stability Testing of New Drug Substances and
Products
ICH Q2B Validation of Analytical Procedures: Methodology
ICH Q3A(R) Impurities in New Drug Substances
ICH Q3B(R) Impurities in New Drug Products
16

17. 17
Stress testing
 To identify potential degradants (degradation
pathways) of the API and assess if they can be
formed during manufacture or storage of the FPP
(intrinsic stability of the API).
 To validate the stability indicating power of the
analytical procedures.
 To identify stability-affecting factors such as ambient
temperature, humidity and light and to select packing
materials, which protect the FPP against such
effects.

18. 18
Stress testing
Recommendations in Supplement 2:
 Should lead to the degradation of the main
compound, but not more than 5-15%.
 Should lead to a good predictability of degradation
pathways (i.e., a low probability of "drastic" or
"false" degradation)
 Should be conducted for no longer than three
months.

19. Stress testing of API in solution
Storage conditions Testing period*
pH ± 2, room temperature 2 weeks
pH ± 7, room temperature 2 weeks
pH ± 10-12, room temperature 2 weeks
H2O2, 0.1-2% at neutral pH,
room temperature
24 hours
* Storage times given or 5-15% degradation, whatever comes first
19

20. 20
Stress testing
Temperature
A thin layer of the API is wetted with
water and is kept at 80°C for 4 weeks in a
Petri dish (open system) with sampling
once a week
Assay:
S1:
D1:
Total unspecified:
Total impurities:
Humidity
A thin layer of the API is wetted with
water and kept at 40°C / 100% RH for 4
weeks in a Petri dish (open system) with
sampling once a fortnight
Assay:
S1:
D1:
Total unspecified:
Total impurities:
Oxidation
Oxygen is bubbled slowly through the
oxygen-saturated aqueous
solution/suspension (under constant
mixing) of the API for 24 hours with
sampling every eight (8) hours
Assay:
S1:
D1:
Total unspecified:
Total impurities:

21. An optimal degradation pattern generated during stress testing would
show only those degradation products observed at the end of shelf life in
regulatory stability studies and those that might appear if the API or FPP if
not manufactured, handled or packed properly.
Chromatograms thus obtained will be representative and not too
complicated to evaluate, which may be the case if drastic conditions are
applied and many second- and third-generation degradation products are
formed.
21
Stress testing

22. 22
Stress testing
Degradation factor Conditions
Thermal ≥ 60 oC
Humidity ≥ 75% RH
Acid 0.1N HCl
Base 0.1N NaOH
Oxidative Oxygen gas, or 3% H2O2
Photolytic Metal halide, Hg, Xe lamp, or UV-B
fluorescent
Metal ions
(optional)
0.05M Fe2+ or Cu2+

23. 23
Storage temperature
(°C)
Relative
humidity
(%)
Minimum time period
covered by data at
submission (months)
Accelerated: 40±2 75±5 6
Intermediate: 30±2 65±5 12
Long term: 25±2 60±5 12 (6)

24. 24
 A storage statement should be proposed for the
labeling (if applicable), which should be based
on the stability evaluation of the API.
 A re-test period should be derived from the
stability information, and the approved retest
date should be displayed on the container label.
 An API is considered as stable if it is within the
defined/regulatory specifications when stored at 30±2oC
and 65±5% RH for 2 years and at 40±2oC and
75±5%RH for 6 months.

25. STABILITY TESTING - FPP
25
Regulatory stability testing
Stress testing (forced degradation)

26. 26
 Loss/increase in concentration of API
 Formation of (toxic) degradation products
 Modification of any attribute of functional relevance
 Alteration of dissolution time/profile or bioavailability
 Decline of microbiological status
 Loss of package integrity
 Reduction of label quality
 Loss of pharmaceutical elegance and patient acceptability

27. 27
Stability studies should include testing of those
attributes of the FPP that are susceptible to change
during storage and are likely to influence quality,
safety and/or efficacy. For instance, in case of
tablets:
♦ appearance ♦ hardness
♦ friability ♦ moisture content
♦ dissolution time ♦ degradants
♦ assay ♦ microbial purity

28. 28
 At the time of submission data from stability studies should
be provided for batches of the same formulation and
dosage form in the container closure system proposed for
marketing.
 Stability data on three primary batches are to be provided.
The composition, batch size, batch number and
manufacturing date of each of the stability batches should
be documented and the certificate of analysis at batch
release should be attached.
 Where possible, batches of the FPP should be
manufactured by using different batches of the API.

29. 29
 A 5% change in assay from its initial value.
 Any degradation product exceeding its
acceptance criterion.
 Failure to meet the acceptance criteria for
appearance, physical attributes, and functionality
test (e.g., color, phase separation, hardness).
 As appropriate for the dosage form, e.g., failure to
meet the acceptance criteria for dissolution for 12
dosage units.

30. 30
Storage conditions Testing period*
40°C, 75 % RH; open
storage**
3 months
50-60 °C, ambient RH; open
storage
3 months
Photostability; according to
ICH
according to ICH
* 3 months or 5-15% degradation, whatever comes first
** For API1-API2, or API-excipient, or FPP without packing
material, typically a thin layer of material is spread in a Petri dish.
Open storage is recommended, if possible.

31. • What is it?
– Any environmental condition that may affect performance of your test
system.
Stress Testing
Heat Humidity Light
• Factors:-
– Factors that affect stability:
• Inherent stability of key components of test
• Membranes, paper, tapes, and other structural materials
• Stabilizers, wetting agents, blocking agents
• Packaging and desiccating agents and their capabilities
• Ideal and actual moisture contents of packaged test
31

32. • Determine which component(s) failed
•Interchange components with a working test to isolate the source of
the problem
•Change in components may be necessary
•May need to change stabilizers
•May need to change surfactants
•Consider other types of adhesives, tapes and cover tapes, even
membranes and plastic supports
32

33. Bracketing
• Stability studies should be performed on each individual strength, dosage
form and container size of the pharmaceutical product. If dosage form is the
same, then bracketing can be applied to:
• Different strengths (including FDC products)
– have identical formulations (including FDC products)
– are made with closely related formulations
• Container-closure system is the same and either the container size or the fill
size varies
• Even when the container-closure system varies bracketing is possible with
some justification. Such justification might be the demonstration that the
product is not water sensitive, or the discussion of the relative permeation
rates of the closure systems.
33

34. BRACKETING DESIGN
Pack type
Label strength and batch numbers (X,Y,Z)
10 mg 20mg 30mg
X Y Z X Y Z X Y Z
Alu/Alu blister cards of 10 tablets + + + - - - + + +
HDPE pack of 30 tablets + + + - - - + + +
HDPE pack of 100 tablets - - - - - - - - -
HDPE pack of 1000 tablets + + + - - - + + +
34

35. Matrixing
• Matrixing is the statistical design of a stability schedule
• Each storage condition should be treated separately
under its own matrixing design
• At a given time point (other than the initial or final ones)
not every batch on stability needs to be tested
• Full testing must be performed at the maximum storage
period at the time of submission
35

36. Matrixing design
One-half matrix design – long-term stability studies
Testing
station
0 3 6 9 12 18 24 36
S
1
Batch 1 + + - - + - + +
Batch 2 + - + + + - + +
Batch 3 + - + - + + - +
S
2
Batch 1 + - + + + + - +
Batch 2 + + - - + + - +
Batch 3 + + - + + - + +
36

37. Shelf life (expiration dating period, conformance period)
• The time period during which an API is expected to remain within the
approved shelf-life specification, provided that it is stored under the
conditions defined on the container label.
• The period of time during which a pharmaceutical 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.
37

38. Design an experimental setup
 Prepare a control sample
 Store samples at appropriate conditions
 Take samples at periodic intervals
 Measure quality changes
 Determine the fastest quality degradation and use
its quality index criteria
 Determine shelf life based on the quality index
criteria 38

39. ICH is a unique project started in 1990, bringing together the regulatory
authorities of the European Union, USA and Japan and experts from the
pharmaceutical industry from these regions.
ICH aims to produce a single set of technical requirements for the registration
of drug products and hence the development process.
Scope :-
ICH produces guidelines which covers:
Efficacy
Quality
Safety
Multidisciplinary, for traditional pharmaceutical and biotechnology
sector.
39

40. ICH Follows Five step process for
recommendation for adoption
Step I Consensus building
Step II Released for Consultation-Start of Regulatory
Action
Step III Regulatory Consultation
Step IV Recommended for Adoption
Step V Implementation
40

41. ICH : Efficacy 17 Efficacy Guidelines
ICH : Multidisciplinary 05 Multidisciplinary Guidelines
ICH : Quality 22 Quality Guidelines
41

42. No. Guidelines
Q1A(R2) Stability Testing of New Drug Substances and Products
Q1B Stability Testing: Photostability Testing of New Drug Substances and
Products
Q1C Stability Testing for New Dosage Forms Annex to the ICH
Harmonised Tripartite Guideline on Stability Testing for New Drugs
and Products
Q1D Bracketing and Matrixing Designs for Stability Testing of New Drug
Substances and Products
Q1E Evaluation for Stability Data
Q1F Stability Data Package for Registration Applications in Climatic
Zones III and IV
2A Text on Validation of Analytical Procedures
42

43. No. Guidelines
2B Validation of Analytical Procedures Methodology
Q3A(R) Impurities In New Drug Substances
Q3C(M) Impurities : Residual Solvents (Maintenance)
PDE for N-Methylpyrrolidone (NMP)
Q3C(M) Impurities : Residual Solvents (Maintenance)
PDE for Tetrahydrofuran
Q3C Impurities: Guideline for Residual Solvents
Q6A Specifications: Test Procedures and Acceptance Criteria
or New Drug Substances and New Drug
Products:Chemical Substances
Q7A Good Manufacturing Practice Guide for
Active Pharmaceutical Ingredients
Q8 Pharmaceutical Development
Q9 Quality Risk Management
43

44. • Specifications: Test Procedures and Acceptance Criteria for
Biotechnological/Biological Products
• Good Manufacturing Practice Guide for Active Pharmaceutical
Ingredients
• Pharmaceutical Development
• Quality Risk Management
• Pharmaceutical Quality System
• Quality Implementation Working Group
44

45. • How can I determine if a product model in the R&D
stage will be stable enough to become a viable
product with acceptable performance throughout its
expected shelf life?
• How can I develop a set of accelerated stress
conditions that will be a guide to real time stability
data?
45

46. 46
 A systematic approach should be adopted in the
presentation and evaluation of the stability
information, which should include, as appropriate,
results from the physical, chemical, biological and
microbiological tests, including particular attributes of
the dosage form
 The results should be presented both as a table and as
a graph and not as data sheets
 The Applicant should evaluate the stability data
Stability Reports

47. 47
1. Tabulate and plot stability data on all attributes at
all storage conditions and evaluate each attribute
separately.
2. No significant change at accelerated conditions
within six (6) months.
3. Long-term data show little or no variability and
little or no change over time.
Evaluation: Best case

48. 48
Evaluation: Best case
4. Accelerated data show little or no variability and little
or no change over time.
5. Statistical analysis is normally unnecessary and
providing a justification for the omission should be
sufficient
6. Proposed retest period or shelf life = double of period
covered by long-tem data (X) but NMT X + 12
months
7. A retest period or shelf life granted on the basis of
extrapolation should always be verified by additional
long-term stability data

49. 49
Release and shelf-life specification
 It may be appropriate to have justifiable differences
between the shelf life and release acceptance
criteria based on the stability evaluation and the
changes observed on storage.
 Shelf-life acceptance criteria should be derived
from consideration of all available stability
information.
 Release and shelf-life dissolution acceptance
criteria

50. 50
Commitment
 For confirmation of provisional
(tentative) shelf-life, real-time data are
required
 First 3 production batches on stability
 Follow up stability testing (FUST) – one
batch per year

51. 51
Additional or New stability data
 Variations affecting one or more steps of the
same route of synthesis of an API
 Change in the route of synthesis of an API
 Change in composition of the FPP
 Change in immediate packaging of the FPP

52. 52
Conclusion
 Stability studies should be planned on the basis of
pharmaceutical R+D and regulatory requirements.
 Forced degradation studies reveal the intrinsic
chemical properties of the API, while formal
stability studies establish the retest date.
 The shelf life (expiry date) of FPPs is derived from
formal stability studies.
 Variability and time trends of stability data must be
evaluated by the manufacturer in order to propose
a retest date or expiry date.