Mandatory EU Safety Testing
Compatibility Testing
The purpose of the compatibility test is to evaluate the migration of chemicals between the cosmetic product and its container – primary packaging. Packaging can directly affect finished product stability and safety because of the possible physical and chemical interactions between the product, the package, and the external environment. The Compatibility test may include:
- Interaction between the product and the container;
- Barrier properties of the container;
Several aspects are checked for both the container and the product:
- Waterproofness of the container;
- Phthalate concentration in the product;
- Aging of the container;
- Stability of the emulsion: there can be 2 phases formed for a product if it is unstable or if there are interactions between the packaging and the product. To check for the stability, the sample is observed both in the original packaging and in a control container usually a glass (inert) container.
- Restitution test: to check that the whole product is accessible to the user considering its packaging
- Transportation test
General Considerations
There are no standard protocols for the compatibility testing of the cosmetic products. An appropriate assessment may be made based on the knowledge of the formulation and primary packaging materials and experienced expert judgment.
Test Method
Why: to test the potential migration of small amounts of substances from the primary packaging material to the formulation.
When: before the placing on the market of the cosmetic product and while development or Good Manufacturing Practices or GMP random controls.
How: The environmental conditions and the periodicity of the analysis can be the same as those mentioned for the formulation Stability Studies.
In this test, several alternative container materials may be analyzed to determine which is most suitable for the product.
Types of container material and main evaluations:
- In the case of cellulose packaging (such as cartridges, trays, displays and cardboard packages), evaluation is necessary for:
- alterations in the paper and formulation structure, checking for possible migration of components that could contaminate the product (e.g.: sachets);
- physical-chemical stability of the packaging;
- alterations in the formulation – appearance, color, odor, among others;
- appearance and functionality of the package;
- barrier function (e.g., permeation of oil, water or gases);
- metal determination, whenever applicable.
- In the case of metal packaging, evaluation is necessary for:
- delamination, when applicable;
- corrosion;
- alterations in the formulation – appearance, color, odor, among others;
- appearance and functionality of the package;
- formula reaction;
- polish or resin integrity (internal and external);
- metal determination, whenever applicable;
- functionality.
- In the case of plastic packaging (such as polypropylene (PP), high density Polyethylene (PEAD), low density Polyethylene (PEBD), Polyethylene Terephthalate (PET), Polystyrene (PS) and Poly vinyl chloride (PVC)), evaluation is necessary for:
-
- alterations in the formulation – appearance, color, odor, among others;
- appearance and functionality of the package;
- interaction and migration of components between package and porosity to water vapor;
- light transmission;
- heat-sealing (whenever applicable);
- deformity (collapse or bending).
- In the case of glass packaging, evaluation is necessary for:
-
- alterations in the formulations – appearance, color, odor, among others;
- appearance and functionality of the package;
- mechanical resistance of the package.
- As for pressurized packaging, the evaluations must be in conformity with the characteristics of the previously evaluated materials and also consider the influence of the propellant on the formulation and on the package materials. What is generally evaluated:
-
- performance of the product in accordance with its functionality;
- corrosion and electrolysis of the package;
- internal and external polish control (porosity), whenever applicable;
- homogeneity of coatings and linings – bubble formation, fissures and corrosion;
- performance of the valve and it’s components;
- presence of electrolytes, odor and formulation precipitation.
Conclusion Report
The conclusion on compatibility report should contain:
- Identification of the lab conducting the testing
- Identification of the product
- Identification of packaging material used in the test
- A description of the methodology used – the protocol
- Study conditions (sample storage conditions, test time period and periodicity of the evaluations)
- The result of the report
- The signature of the person responsible for the study
- What to consider based on the conclusion of the report:
- If migration is dependent on the storage conditions, the correct conditions should be indicated on the labeling of product.
- If the formulation is sensitive to light or air and would degrade in a way that impacts consumer safety or product efficacy, appropriate packaging material should be used.
As an Obelis client, you can take advantage of our network for pre-approved Safety Testing facilities to obtain any tests you may be missing in parallel to the EU Compliance process.
Challenge Testing
Challenge testing is mandatory for all cosmetic products for which a risk of microbial growth during normal conditions of storage or use is identified. Preservatives are included in most cosmetic product formulations to protect them from microbiological contamination during normal consumer use. The purpose of the challenge test is to verify the reliability of the preservative system during the shelf and usage life of the cosmetic product.
General Considerations
While there are different challenge tests protocols, similar methods are described in the EU Pharmacopeia and US Pharmacopeia. These protocols differ one from the other in the detailed procedures, test organisms, criteria for passing the test and the requirements for validation. Concerning microbiological susceptibility there are differences between three product categories:
- Low microbiological risk products (e.g., products with alcohol content >20%, products based on organic solvents, high/low pH products), for which neither a preservation challenge test nor microbiological quality tests in the finished product are necessary. Nevertheless, scientific justification should be provided detailing the reason why the product is low microbiological risk.
- Single use products, and products which cannot be opened, for which only microbiological quality tests in the finished product are necessary;
- All other products, for which both a preservation challenge test and microbiological quality need to be performed
Test Method
When: The test should be done in at least two phases:
- during development of the product – after adding the preservative system;
- at the end of the stability testing and/or the of formulation compatibility test with the packaging material ( as an evaluation of the protection efficacy in intact, in-use or in ending cosmetic products).
How: The product is inoculated with a known quantity of different microbial pathogens (bacteria, molds, yeasts, etc).
- The micro-organisms used in the challenge test will be issued from official collection strains from many states in the EU to ensure reproducibility of the test (Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans). In-house microorganisms, found as contaminations in the products may be used for additional specific purposes of the challenge testing.
- The challenged product is incubated at a given temperature (22 °C ± 1 °C in the dark).
- Before the test, each cosmetic product is tested for its microbiological contamination
- Samples for determination of plate counts are taken after 0, 7, 14, 21 and 28 days, depending on the protocol used.
The microbial activity of preservatives or any other compound in the finished cosmetic must be ruled out in the challenge test by dilution, filtration, neutralizers or any other means. The experimental performance of the microbial controls and the challenge tests must be laid down and validated by a microbiologist.
Acceptance Criteria
The antimicrobial properties of the product are acceptable if a significant decrease or no increase in viable count of micro-organisms is seen:
- A 2 log reduction in the microorganisms counting after 14 days compared to that at the beginning
- A 0.5 log reduction in the microorganisms counting after 28 days compared to that after 14 days.
Conclusion Report
The conclusions report of Challenge Test shall contain:
- Identification of the lab conducting the testing
- Identification of the product
- Packaging material used in the test
- A description of the methodology used – the protocol
- Study conditions
- The result of the study.
- The signature of the person responsible for the study
As an Obelis client, you can take advantage of our network of pre-approved Safety Testing facilities to fulfill any missing safety testing in parallel with the rest of the EU Compliance process.
Cosmetic Product Stability Test
The purpose of stability testing is to ensure that the cosmetic product maintains its intended physical, chemical and microbiological quality, as well as functionality and aesthetics when stored under appropriate conditions.
General Considerations
Due to the different nature of each cosmetic product, no mandatory Stability Test was established. Each manufacturer given its knowledge on the formulation and the product intended use, may draft and argue the best suited conditions to evaluate the stability of the product. The elements to be considered when drafting the protocol of a stability test:
- Identify the conditions that will “accelerate and predict” the effects of normal conditions of storage and use. Where relevant, consider stresses, including temperature that will enable assessment of product integrity under anticipated product exposure conditions.
- Consider evaluation of critical aesthetic properties such as color, fragrance, texture, and flow, particularly after exposure to conditions designed to stress each specific property.
- Consider variations in the process conditions.
- Consider the impact of the primary packaging on the formulation, as well as any effects which the product might have on the packaging.
Test Method
Why: To ensure that the cosmetic product maintains its intended physical, chemical and microbiological quality, as well as functionality and aesthetics when stored under appropriate conditions.
When: The most common conditions for stability testing of cosmetic products are listed in several published references:
(✓) International Federation of Societies of Cosmetic Chemists, IFSCC Monograph, Number 2 (The Fundamentals of Stability Testing):
|
Temperature |
Humidity |
Duration |
Control |
4°C |
|
Shelf life |
Room Temp |
20 – 25° C |
– |
Shelf life |
Accelerated |
37° C |
– |
3-6 months |
Accelerated |
37° C |
80% |
1 month |
Accelerated |
45° C |
|
1-3 months |
(✓) Cosmetic Regulation in a Competitive Environment (Ch 11 “Stability Testing of Cosmetic Products”)
Room temperature: |
24-25°C |
Accelerated testing: |
37, 45 and 50°C |
Freeze-thaw cycling: |
0 or -5°C |
Elevated humidity: |
80% RH |
How: Stability testing is an experiment in which samples of the formula are put at different environmental/ storage conditions for a set period of time to simulate what will happen to the product during its life cycle. At selected intervals, samples are evaluated for various physical, chemical and performance characteristics to see if and how they have changed.
- Selection of batches: It is recommended to use at least one batch of the cosmetic product, the same batch as the marketed product.
- Container/ Closure system: The container/closure system(s) shall be the same as the one used when placing the product on the market. Any other studies carried out on the cosmetic product outside its immediate container or in other packaging materials can form a useful part of the stress testing of the cosmetic product or can be considered as supporting information, respectively. Appropriate controls (for example, product in glass containers) should be used.
- Stability evaluation parameters:
- Organoleptical properties: color, odor and appearance,
- Physico-chemical properties: pH value, viscosity, density, the monitoring of fomulation ingredients (whenever applicable)
- Microbiological stability: microbial count & Challenge Test of the preserving system made before and/or after the Accelerated Stability Test.
- The compatibility between the content & the container (Compatibility Test)
- Analytical data in relation to other parameters for specific product type
A preliminary test recommended is the centrifugation test. This test predicts emulsion creaming (for powder, liquid/cream products).
• A sample heated to 50°C is centrifuged at 3,000rpm for 30 minutes.
(✓) The product must remain stable and any sign of instability shows the need for reformulation.
If approved in this test, the product can then be submitted to the stability tests.
Preliminary stability test
This test is also known as screening test, accelerated stability test or short-term test.
Why: help in the screening of the formulation.
When: is carried out in the initial phase of product development.
How: the samples can be submitted to:
- heating in ovens,
- cooling in refrigerators,
- to alternate cooling and heating cycles.
Duration of the study: 15 days
The parameters to be evaluated:
- Organoleptic characteristics: appearance, color, odor and flavor, whenever applicable.
- Physical-chemical characteristics: pH value, viscosity, density, or others.
Accelerated Stability Test
An accelerated stability test is also a possibility, none the less, the product will be required to be submitted to more-severe-than-usual conditions. The accelerated stability is also known as normal or exploratory stability test. This test is a predictive study that can be used to estimate the expiry date of the product. Duration of the study: generally 90 days.
Acceptance Criteria
The samples are evaluated against the standard sample (must remain unchanged during the whole life cycle of the product) and with products that are considered as ‘’references’’ submitted to the same test conditions. Generally limits of acceptance are defined for the evaluated parameters. The interpretation of the data obtained during the Stability Test depends on criteria established in accordance with the formulator’s experience.
Criteria |
Limits of acceptability |
Appearance |
The product must, maintain its initial appearance under all the conditions except high temperatures, freezer conditions or cycles in which small alterations are acceptable. |
Color and odor |
Must remain stable for at least 15 days when exposed to sunlight. Small alterations are acceptable at high temperatures. |
Viscosity |
The limits of acceptability must be defined by the formulator, considering the visual and sensorial perceptions caused by alterations. The possibility of the consumers also noticing them must be considered. |
Compatibility with the primary packaging material |
The integrity of the package and the formulation must be considered, evaluating the weight, the sealing and the functionality |
In cases where the monitoring of the active ingredient percentage is necessary, the quality and performance parameters of the product must be considered. Other parameters can be established according to the formulator and the products’ specifications.
Conclusion Report
The Conclusion report on stability study shall contain:
- Identification of the lab conducting the testing;
- Identification of the product;
- Containing Primary packaging material used in the test;
- A description of the methodology used to determine the product’s minimum durability. If applicable, the specific preservation precautions should be mentioned;
- Study conditions (sample storage conditions, test time period and periodicity of the evaluations).
In addition, the following should also be provided:
- Evidence that the composition of the product used for stability testing corresponds to the product actually placed on the market;
- The results of the preservative efficacy study, e.g., challenge test, if applicable;
- When applicable, the period after opening (PAO) and its justification;
- The signature of the person responsible for the study.