Stability tests for cosmetics should be performed when:<\/p>\n\n\n\n
- A new formula is developed;<\/p>\n\n\n\n
- An existing on-market product is reformulated;<\/p>\n\n\n\n
- The production method or production site is altered;<\/p>\n\n\n\n
- The raw material supplier is different;<\/p>\n\n\n\n
- The packaging is changed, to ensure that the formula remains compatible with the packaging.<\/p>\n\n\n\n
Stability testing is not a \u201cstandard\u201d process due to the variety and complexity of cosmetic formulas and packaging. Therefore, for each formula, the manufacturer should select the most relevant parameters to be evaluated based, for example, on the product\u2019s vulnerabilities and its anticipated shipping, storage and use conditions.<\/p>\n\n\n\n
The establishment of adequate protocols and procedures for stability testing should be based on guidelines provided, for example, by the FDA (Food and Drug Administration<\/em>) and COLIPA (The European Cosmetic and Perfumery Association<\/em>) and include:<\/p>\n\n\n\n - Tests that can \u201cpredict\u201d the effects of regular storage and use conditions and, when relevant should include stress tests to allow the assessment of the integrity of a product under extreme conditions.<\/p>\n\n\n\n - Evaluation of aesthetic properties such as colour, fragrance, texture and viscosity during and after the exposure to the test\u2019s parameters;<\/p>\n\n\n\n - Considerations of variations in process conditions;<\/p>\n\n\n\n - Packaging compatibility.<\/p>\n\n\n\n When a formula is first developed, preliminary stability testing can be made using test samples from laboratory or pilot batches to establish the reliability of the formulas and packaging, which can include more extreme protocols than those carried out during the stability testing of final products. However, as development continues, more precise determinations of the stability of representative batches of the commercial product are necessary.<\/p>\n\n\n\n Os Accelerated tests<\/strong> , are the most common form of stability testing and are designed to predict the stability of a formula since cosmetics have a short development cycle. Predictions attained from these studies are accepted provided that the producer carries out regular post-launch studies of samples stored at ambient temperatures. To predict the stability of a cosmetic product, appropriate conditions regarding, temperature, duration of the test and humidity should be selected according to the product category. Tests are often performed at set temperatures of 5 \u00b0C, 25 \u00b0C, 37 \u00b0C, 40 \u00b0C or 45 \u00b0C and at set relative humidity levels of 60%, 65% or 75% during 1, 3 or more months, depending on the cosmetic.<\/p>\n\n\n\n The Packaging<\/strong> can affect final product stability due to interactions between the formula, the package and the external environment, therefore, stability testing should include packaging as similar as possible to the package in which the cosmetic will be marketed. Such interactions include adsorption and chemical reactions between the cosmetic and the container.<\/p>\n\n\n\n During a cosmetic\u2019s shelf life, its properties may change as the product ages, hence during the stability testing the following parameters should be evaluated:<\/p>\n\n\n\n - Colour, odour and appearance;<\/p>\n\n\n\n - Packaging changes;<\/p>\n\n\n\n - pH;<\/p>\n\n\n\n - Viscosity;<\/p>\n\n\n\n - Weight changes;<\/p>\n\n\n\n - Microbiological quality.<\/p>\n\n\n\n Given the subjectivity adjacent to accelerated testing, it is advisable to conduct real-time monitoring to confirm stability testing\u2019s results.<\/p>\n\n\n\n During shipping, storage, retail and use, cosmetics can be subject to extreme temperature and light conditions, which can be included in stability testing to ensure that the product reaches the consumer in the best conditions.<\/p>\n\n\n\n To assess a formula\u2019s response to temperature<\/strong> extremes temperature cycles and or freeze\/thaw tests can be applied. During the freeze\/thaw cycle, the product should undergo three 24-hour cycles of temperatures testing from -10 \u00b0C to 25 \u00b0C. An even more rigorous test includes five cycles of temperatures testing from -10 \u00b0C to 45 \u00b0C, this test puts the formulation under tremendous stress revealing possible inadequacies in a short timeframe when compared to storage at a constant temperature. For all cosmetics marketed in clear packaging, light<\/strong>stability testing should be performed. Finally, to determine the effects of shipping movements on the formula or the packaging both mechanical shock<\/strong> testing or vibration testing can be carried. Among the problems uncovered by these tests are suspension problems, instability of emulsions and creams (phase separation, tendency to crystalize or cloud), package design issues (wrinkling or loss of labels) and corrosion of internal lacquers in aluminium tubes.<\/p>\n\n\n\n To sum up, stability testing aims to guarantee that a cosmetic product meets its intended physical-chemical and microbiological quality standards, as well as functionality and aesthetics. By carrying out suitable stability testing manufacturers can identify any physical and chemical vulnerabilities of their product early-on, allowing the producers to make needed adjustments to the formula or final product in order to avoid marketing improper products and consumer\u2019s complaints. Therefore, cosmetic manufacturers benefit greatly from the incorporation of routine stability testing into the lifecycle of their products. By gathering critical information on different formulas and final products, manufacturers can develop better products, establish shipment and storage conditions, provide the customer with suitable application methods, and determine the appropriate packaging in order to provide consumers with the best cosmetic products.<\/p>","protected":false},"excerpt":{"rendered":" Quando deve ser realizado um teste de estabilidade? Os estudos de estabilidade para cosm\u00e9ticos devem ser efetuados quando: – Uma nova f\u00f3rmula \u00e9 desenvolvida; – Um produto existente no mercado \u00e9 reformulado; – O m\u00e9todo de produ\u00e7\u00e3o ou o local de produ\u00e7\u00e3o \u00e9 alterado; – O fornecedor da mat\u00e9ria-prima \u00e9 diferente; – A embalagem \u00e9 […]<\/p>","protected":false},"author":3,"featured_media":329,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-328","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-cosmeticos"],"_links":{"self":[{"href":"https:\/\/pharmilab.likealot.pt\/en\/wp-json\/wp\/v2\/posts\/328","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pharmilab.likealot.pt\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/pharmilab.likealot.pt\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/pharmilab.likealot.pt\/en\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/pharmilab.likealot.pt\/en\/wp-json\/wp\/v2\/comments?post=328"}],"version-history":[{"count":1,"href":"https:\/\/pharmilab.likealot.pt\/en\/wp-json\/wp\/v2\/posts\/328\/revisions"}],"predecessor-version":[{"id":330,"href":"https:\/\/pharmilab.likealot.pt\/en\/wp-json\/wp\/v2\/posts\/328\/revisions\/330"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/pharmilab.likealot.pt\/en\/wp-json\/wp\/v2\/media\/329"}],"wp:attachment":[{"href":"https:\/\/pharmilab.likealot.pt\/en\/wp-json\/wp\/v2\/media?parent=328"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/pharmilab.likealot.pt\/en\/wp-json\/wp\/v2\/categories?post=328"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/pharmilab.likealot.pt\/en\/wp-json\/wp\/v2\/tags?post=328"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}What to do during a stability test?<\/h4>\n\n\n\n
Conclusion<\/h4>\n\n\n\n