Stability Testing for Cosmetic Products
SHAPYPRO coordinates stability testing for cosmetics and other regulated products to assess whether they maintain their physical, chemical, microbiological, functional and sensory properties over time.
Studies are adapted to the product, formulation, packaging and expected storage and use conditions, providing useful information for shelf-life estimation, change detection and technical documentation.
- Accelerated stability
- Real-time studies
- Product-packaging compatibility
- ISO/TR 18811
Stability Studies and Product Quality
Stability studies monitor how a product evolves under defined conditions and assess whether it maintains the characteristics required for quality, safety and functionality.
Planning should consider the formulation, preservative system, packaging, intended use and environmental factors that may affect the product during storage, transport or use.
For cosmetic products, the resulting data may support shelf-life definition, the period after opening, storage conditions and the overall assessment of product safety and quality.
Types of Stability Studies
The study approach is selected according to the development stage, technical objective and level of evidence required.
Preliminary Stability or Screening
Initial evaluation of the formulation to detect early changes, incompatibilities or undesirable behaviour before development is completed.
It may be carried out without the final packaging and can support formulation comparison and the selection of subsequent test conditions.
Accelerated Stability Testing
Study performed under controlled conditions that increase stress on the product, such as elevated temperatures or thermal variations.
It provides predictive information and helps identify trends in a shorter period, but does not by itself replace confirmation through real-time stability testing.
Long-Term or Real-Time Stability Testing
Monitoring of the product under representative storage conditions over an extended period. It confirms the behaviour observed in accelerated studies and provides real data to support the proposed shelf life.
In-Use Stability
Assessment under conditions that simulate routine use, including repeated opening, handling and environmental exposure.
This approach is useful for evaluating product behaviour after opening and its interaction with the packaging system.
Parameters and Test Conditions
Parameters and conditions are defined according to the nature of the product, foreseeable risks and study objectives. Not every project requires the same determinations or checkpoints.
Physical and Sensory Properties
Appearance, colour, odour, texture, viscosity, homogeneity, phase separation and other relevant observable changes.
Chemical Properties
Parameters such as pH, component concentration, degradation products or other determinations required to assess formulation stability.
Microbiological Quality
Monitoring of microbiological parameters when required, coordinated with the microbiology control and Challenge Test applicable to the product.
Functionality and Efficacy
Verification that the product maintains its intended function and, where relevant, properties associated with efficacy or claims.
Product-Packaging Compatibility
Observation of leaks, deformation, colour changes, loss of integrity, migration or other interactions between the formulation and packaging.
Exposure Conditions
Temperature, humidity, light, thermal cycling, freeze-thaw cycles or other conditions selected according to the product and technical objective.
Products Evaluated
Studies are designed for products and formulations whose characteristics must be maintained throughout storage, distribution and intended use.
Cosmetic Products
Creams, emulsions, gels, shampoos, sunscreens, makeup, hair products and other cosmetic formulations.
Biocides, Antiseptics and Disinfectants
Assessment of the physical, chemical and functional behaviour of products subject to specific quality and preservation requirements.
Chemical Products and Technical Formulations
Substances, mixtures and formulations requiring monitoring of properties, compatibility or behaviour throughout their shelf life.
Raw Materials and Prototypes
Comparative studies during development, reformulation or the selection of components and packaging systems.
Stability Study Process
SHAPYPRO adapts the planning and coordination of each study to the characteristics of the product and the documentation required by the project.
Initial Technical Review
Review of the formulation, product, packaging, intended use, storage conditions and available technical information.
Protocol Design
Definition of study type, batches or samples, exposure conditions, checkpoints, parameters and evaluation criteria.
Sample Preparation and Storage
Organisation of samples in the relevant packaging and under the conditions established in the protocol.
Periodic Checkpoints
Assessment of the defined parameters at scheduled times to identify changes, trends or deviations.
Technical Evaluation
Combined interpretation of results to assess product behaviour and compatibility with the conditions studied.
Results, Shelf Life and Documentation
Results make it possible to identify trends, detect relevant changes and assess whether the product remains within the defined acceptance criteria.
Accelerated studies may provide an initial stability estimate and support a provisional shelf life. Confirmation should be based on real-time data and continued product monitoring.
Documentation may include the protocol, test conditions, checkpoint results, trend evaluation, observed deviations and the technical conclusions of the study.
ISO/TR 18811
Technical reference for planning and evaluating stability studies for cosmetic products.
Microbiology Control
Complements the study by assessing the microbiological quality of the product where applicable.
Challenge Test
Specifically evaluates preservative-system efficacy against controlled contamination.
Stability Testing Adapted to Each Project
Every product has different risks, use conditions and documentation needs. The study type, parameters and checkpoints must therefore be defined specifically for each project.
SHAPYPRO provides technical coordination to select the appropriate approach, organise monitoring and deliver clear documentation for development, quality control and compliance purposes.
