Transcript Diapositive 1

Stability Testing
Rutendo Kuwana
Technical Officer
Prequalification of Medicines Program
WHO
Overview
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Scope of presentation – Generic/Multisource preparations
API - Stress Testing
Selection of Batches
Container Closure System
Methods to be validated
Specifications: Stability indicating quality parameters
Testing Frequency
Storage Conditions
Evaluation of data
Bracketing/Matrixing
Common deficiencies
PQ Assessors training, Jan 2011
The Role of Stability in Drug
Development
• Stability studies play a central role in drug
development
• Permit understanding of the molecule
• Essential for developing analytical methods
• Essential for selecting packaging for drug substance
and drug product
• Essential for choosing storage conditions for drug
substance and drug product
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API
Stress Studies
• When available, it is acceptable to provide relevant
data published in the scientific literature to support
the identified degradation pathways and products.
• When no data are available, stress testing should be
performed.
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The Role of Stress Testing
• Identification of degradation pathways
• Identification of degradants
• Determination of which type(s) of stress affect the
molecule
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Photostability
High Temperature
Low Temperature
Oxidation
pH extremes
Water
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API stability
Stress testing
• Requirement: 1 API batch.
• Photostability testing: generally as per Q1B, however
for PQP, literature data can support/replace
experimental data:
If “protect from light” is stated in one of the officially
recognized pharmacopoeia for the API, it is sufficient
to state “protect from light” on labeling, in lieu of
photostability studies, when the container closure
system is shown to be light protective.
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Oxidation
• Typically done by placing the drug substance in
aqueous solution with hydrogen peroxide
• Goal is significant degradation (typically 10-30% of
API)
– Can identify degradants
– Determine whether protective packaging is required
– Determine if an antioxidant should be considered for the
drug product formulation
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pH Extremes
• Typically done by adding drug substance to buffered
aqueous solutions at pH values from 1-10.
• Can be complicated by limited solubility of the drug
substance under different pH conditions
• Again, the goal is significant degradation
– Determine degradants
– Decide if the molecule will survive passage through the stomach
• Is enteric coating necessary?
• Should the drug be given by injection?
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API stability
Stress testing – Typical Stress conditions
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Identifying Degradants
• Predicting routes of degradation
– Acid/base hydrolysis of esters and amides
– Oxidation of thiols, alcohols and amines
– Loss of methyl groups
• Synthesizing possible degradants
– Prepare possible degradant
– Known Structure
– Test it in potential analytical method
• Detectability
• Separation from parent peak
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Stress studies:
Approach
• Investigate impurities/degradants appearing at greater than (or
approaching) the identification threshold, (the limit on
individual unknowns) under long-term and accelerated
conditions.
• Mass balance assessment if required to be based on the
decrease in assay value and the increase in the amount of
degradation products.
• Process related impurities to be monitored at release only with
no need to monitor during long-term stability. However, if they
increase during storage, or new impurities develop, they should
be considered as “degradants” or “degradation products”, and
analytical methods must be developed to monitor them.
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Examples of physical stability stress testing conditions
for drug substances
- Industry Perspective
(Source Handbook of stability testing and pharmaceutical development regulations, methodologies, and best practices)
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API - Selection of Batches
• Primary Batches : Batches used in stability studies to
establish retest (API) or shelf-life (FPP).
• Generally at least 3 pilot batches.
Even though TRS 953 Annex 2 says for existing API known to be stable data
from at least 2 batches should be provided
• API - Pilot batches must be of the same synthesis
route, and method of manufacture and procedure
that simulate the final process for production
batches.
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FPP Stability
Selection of Batches
• Each strength and container type/size should be studied
unless bracketing/matrixing is applied.
• FPP batches should use different lots of API where possible;
• NLT 2 batches of at least pilot scale
• For uncomplicated FPP (e.g. immediate-release solid FPPs
(some exceptions), non-sterile solutions), NLT 1 batch at least
pilot scale and a second batch which may be smaller (e.g.
solid oral dosage forms, 25 000 or 50 000 tablets/capsules)
• Batches should be as proposed wrt:
– Formulation
– Container/closure system
– Manufacturing process simulating production process
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Container Closure System
• Should be the same or simulate the container
proposed for storage/distribution unless justification
provided (i.e. container used in studies is less than or
equally protective compared to proposed container)
• a functionally similar container may be used to mimic
the cardboard or plastic drum that is usually used to
store raw material
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Importance of Analytical Methods in
Development Stability Studies
• Without analytical methods it is not possible to know
what has happened during stability
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Assay
Impurities/Degradation Products
Dissolution
Chiral Purity
Preservative Content
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Methods Must be Stability-Indicating
• Analytical methods must effectively separate and permit
quantification of degradants (including use of purity tests)
• Any significant changes in drug substance or drug product
quality over time must be detectable
– Increase in degradants
– Change in dissolution behavior
– Change in stereochemistry
• cis to trans or vice-versa
• optical isomers interconverting
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Method Validation
• Types of Analytical Procedures to be Validated
– Identification tests;
– Quantitative tests for impurities' content;
– Limit tests for the control of impurities;
– Quantitative tests of the active moiety in samples
of drug substance or drug product or other
selected component(s) in the drug product.
• Drug product assay
• This will also include quantifying dissolution results
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API Stability: Specifications
Specifications: test attributes susceptible to change.
• Testing should cover physical, chemical, biological and
microbiological attributes e.g. appearance, assay, degradation
plus others susceptible to change.
• For impurities, a specification for individual and total
impurities must be set. Numerical data for individual (known
and unknown) and total impurities to be reported instead of
conforms or complies.
• NB: The upper and lower acceptance criteria limits for
innovator products are based on the potency and/or impurity
levels of the clinical lots and safety and efficacy
considerations. There is no justification, normally, for generic
source to request for less stringent specifications.
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Other parameters to be
monitored
• Commonly where the API is low solubility and
micronized, and the FPP is low dose - PSD is critical
• Due to the potential for settling of material on
storage, stability results for PSD should be provided to
address this issue.
• Moisture is particularly important for solid orals in
blisters and strips.
• Efficacy of additives and assay of preservatives
• Container/closure interactions, when applicable
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Testing Frequency
Long term:
Year 1: every 3 months
Year 2: every 6 months
Subsequent years: annually
Accelerated:
Minimum three points including t0 and tfinal, e.g. 0, 3, 6.
Intermediate:
Four points including t0 and tfinal, e.g. 0, 6, 9, 12.
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Minimum Data Requirements at time of
submission – API and FPP
RH (%)
Storage Temp (◦C)
Min. Time period
(months)
Accelerated 40±2
75±5
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Intermediate *
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Long-term 30±2
65±5 or 75±5 (API
only)
75±5 (FPP)
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*Where long-term conditions are 30ºC±2ºC/65%±5%RH or
30ºC±2ºC/75%±5%RH, there is no intermediate condition.
For API when a valid CEP is provided or APIMF is referred to: no data is required
if the proposed retest is as per retest on CEP/APIMF; if retest period longer than
the CEP is proposed, submit data meeting above requirements
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Storage Conditions
• Conditions should test the API/Product's thermal
stability and, if applicable, moisture sensitivity
• For PQ submissions long-term studies should be
conducted at 30°C ± 2 °C/75 % RH ± 5% to
account for all climatic zones, including IVa/b
countries. (strict requirement as of September 2011)
• There is therefore no Intermediate Condition
• use of alternative long-term conditions to be justified
and should be supported with appropriate evidence
e.g. products unstable under these conditions
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Accelerated Stability
• Stability study run under more stressful conditions than expected for long
term storage to account for excursions outside the label storage conditions
e.g. during shipping or handling
• Acc Storage condition should be guided by intended climatic condition in
which API/FPP will be stored
• Different from stress studies in that the goal is to get a quick understanding
of what may be expected from a long term study
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Long-term conditions
Accelerated Conditions
Room temperature (25-30°C)
40°C ± 2°C/75% RH ± 5%
Refrigerated (5°  3°C)
25°C ± 2°C/60% RH ± 5% RH
30°C ± 2°C/65% RH ± 5%
Freezer (-20°C 5°C)
Can range from 5°C ± 3°C or 25°C ± 2°C or 30°C
± 2°C
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or
FPP Stability
In-use studies
• In-use studies are for FPP intended to be diluted or
reconstituted. (multi-use FPP)
• Two different batches (at least pilot), one near the end of its
shelf-life should be used.
NB: there is no in-use requirement (e.g. labelling “use within
30 days”) for dispersible tablets; a single dose is intended to
be dispersed just prior to use.
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“Significant Change”
For API - defined as failure to meet its specification
For an FPP, significant change under accelerated and
intermediate testing conditions is any of:
• More than 5% change in assay from initial;
• Degradant exceeding acceptance limit
• Failure to meet acceptance criteria for appearance, physical
attributes and functionality (e.g. colour, phase separation)
• For tablets e.g. Failure to pass S2/L2 dissolution testing, i.e.
n=12 (i.e. after failing S1/L1 as well)
• For FPP’s in semi-permeable containers, a 5% loss of water
from initial (3 months at 40◦C/25%)
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ICH Q1E Extrapolation
• Can extend expiration dating or retest date beyond
available long-term stability data if
– Sufficient long-term data is available to assess any trends
– No significant change is observed within 6 months under
accelerated conditions
– Little or no variability
• This process is spelled out in Q1E decision trees
• Shelf-lives/retest dates established based on extrapolation
must be confirmed by long-term data when available
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Use of Statistics – Q1E
• to establish, with a high degree of confidence, whether a retest
period or shelf life during which a quantitative attribute will
remain within acceptance criteria for all future batches
manufactured, packaged, and stored under similar
circumstances
• Not necessary if data show so little degradation and so little
variability that it is apparent from looking at the data that the
requested shelf-life will be granted
• Regression analysis is considered appropriate
• Examples of statistical approaches included in Appendix B
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Ongoing Stability Studies
• Purpose: to monitor and determine that API/FPP remains
within specifications under the storage conditions, within the
re-test period/shelf life in all future batches
• The programme should be described in a written protocol
• The programme should include at least one production batch
per year, tested at least annually.
• An ongoing study should be conducted after any significant
change to the synthetic route/manufacturing process or
container which may impact stability.
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Stability Commitment
• This is required when data did not cover the proposed re-test/shelf life
(Primary Stability Study Commitment) and/or the primary stability batches
studied did not consist of three production scale batches (Commitment
Stability Studies)
• The applicant must commit to conducting long-term stability trials on the
next production scale batches that are manufactured. The number of
batches required depends on the number of production scale batches
provided in the primary studies (to make at least 3 production batches)
For all post-approval commitments:
• A signed and dated commitment is required.
• An authorised, dated and detailed protocol should be provided, including
storage conditions, testing frequency, specifications, test methods…
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• Outlines recommendations, principles, and
considerations for reduced designs.
• Rarely submitted in PQP dossiers
– Bracketing: testing samples on the extremes of certain design
factors (e.g., strengths, container sizes and/or fills)
– Matrixing: testing a selected subset of the total number of
possible samples for all factor combinations at a specified time
point, while testing another subset of samples at a
subsequent time point
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• Bracketing - Strengths:
– Applicable: strengths of identical or closely related formulations
– Applicable with additional justification (e.g., supporting data): strengths
where the relative amounts of the drug substance and excipients vary
within the product line
– Not applicable: different excipients among strengths
• Bracketing – Container Size, Fill:
– Applicable: same container closure system where either the container
size or fill varies while the other remains constant
– Applicable with additional justification (e.g., supporting data): same
container closure system but both the container size and fill vary
– Not applicable: different container closure systems
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Bracketing - Considerations:
• If stability of extremes are shown to be different, the
intermediates should be considered no more stable than the
least stable extreme
• Selected extreme may be dropped from proposed market
presentations
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• Matrixing:
– applicable:
• strengths with identical or closely related formulations
• container sizes or fills of the same C/C system
• different batches made with the same equipment and process
– applicable with additional justification:
• where the relative amounts of excipients change or different
excipients are used
– not applicable:
• different storage conditions
• different test attributes
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Common Deficiencies
During assessment problem areas that warrant a closer
look/more questions include:
• Data is provided in such a way that trends cannot be
determined, e.g. range of dissolution values but no
average, or limits cannot be assessed, OR average
dissolution but no range of individual values.
• Data shows a lack of mass balance, or variability in
results without trends - may indicate problems with
analytical methods.
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Common Deficiencies
• Expression of results as passes test or similar when a
quantitative figure would be available.
• Failure to include quantitative or semiquantitative
determinations of the content of degradation products, or to
provide only total content rather than values for individual
impurities.
• Use of an HPLC assay procedure to detect impurities without
validation for the purpose. HPLC assay procedures as used for
determination of the API are often unsuitable for separation
and detection of impurities as they use too short a run time.
Such a procedure would be acceptable if validated for
impurity detection. Note, however, that long run times do not
in themselves ensure good separation.
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Reference Documents
Recommended documents that should be consulted for Stability requirements:
– Guideline on submission of documentation for multisource (generic) finished
pharmaceutical product (FPP): Quality Part (In PQP supersedes any other
guidance if there is conflict)
– The WHO stability guideline Stability testing of active pharmaceutical
ingredients and finished pharmaceutical products (WHO Technical Report
Series, No. 953, Annex 2, 2009)
– Health Canada (www.hc-sc.gc.ca/hpfb-dgpsa/tpddpt/index_drugs_information_e.html):
– FDA (www.fda.gov/cder/guidance/index.htm):
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Stability Testing of Drug Substances and Drug Products (draft, 1998)
Drug Substance - CMC Information (draft, 2004)
Drug Product - CMC Information (draft, 2003)
SUPAC series (IR, MR, SS) (and Q&A Document)
Changes to an Approved NDA/ANDA (04/2004) (and Q&A Document)
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• EU EMEA (www.emea.eu.int/Inspections/QWPhome.html):
 Manufacture of the Finished
Dosage Form Annex - Start of
Shelf -Life of the Finished
Dosage Form (05/2001)
 Maximum Shelf-Life for Sterile
Products after First Opening or
Following Reconstitution
(01/1998)
Stability Testing Annex Declaration of Storage
Conditions for Medicinal Products
Particulars and Active
Substances (04/2003)
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 Stability Testing Annex - In-Use
Stability Testing of Human
Medicinal Products (02/2001)
 Stability Testing for a Type II
Variation to a Marketing
Authorisation (04/1998)
Stability Testing for Applications
for Variations to a Marketing
Authorisation (draft 04/2004)