In-Package Cosmetic Stability Testing:

Your Top 5 Questions Answered

Reviewed and Approved by Matilda Baghdasarian, Associate Director, Certified Laboratories 

In-package stability testing is an essential phase for any cosmetic, OTC, personal care product, or dietary supplement company. We aim to provide our customers with the essential knowledge to understand all the steps involved in providing key stability data.  

With that in mind, here are the commonly asked questions we receive about in-package stability testing. The answers will help you navigate the stability phase of testing, making it both easy and informative. 

1) Does Certified Laboratories Provide Stability and Packaging Compatibility Testing Simultaneously? 

We suggest obtaining the finished product to perform stability and compatibility testing simultaneously; doing so will address both testing criteria needs.  

If you do not have the finished goods available, we can begin stability testing using the bulk product. After receiving the finished product, we can proceed with packaging compatibility testing.  

Analytical chemist preparing a personal care product for testing in a cosmetic testing laboratory. 


2) Can Cosmetic Stability Testing be Expedited?   

For accelerated stability testing, plan for a period of 7-8 months to obtain the data confirmation for shelf-life claims, including delivery time.  

As stability testing is dependent on the aging process with time, and as we cannot control time, it is beneficial to prepare in advance for stability testing to make sure a sufficient amount of time is given for the aging process. 

3) How are Reports Released?     

Upon receiving samples for stability projects, a particular set of steps must be followed to obtain the data. The protocol is executed and approved, samples are labeled and placed in the chamber, and testing begins.  

The stability testing report is shared with customers 10 days after the pull date of the samples from the chambers. Reports are reviewed, verified, and released to our online portal for customer access.    

 Stability testing chambers for in-package stability testing of cosmetics, OTC, and personal care products.  


4) What Storage Conditions are Available?     

Certified Laboratories follows International Council for Harmonisation (ICH) guidelines for in-package stability testing. The stability testing team offers the following ICH storage conditions on-site: 

  • 25°C ± 2°C  / 60%RH ± 5%RH 
  • 40°C ± 2°C / 75%RH ± 5%RH 
  • 30°C ± 2°C / 65%RH ± 5%RH 
  • 30°C ± 2°C / 75%RH ± 5%RH 
  • 45°C ± 2°C 
  • 50°C ± 2°C 
  • 60°C ± 2°C 
  • 5°C ± 2°C (Refrigerator) 
  • UV 
  • Photostability [per ICH Q1B guidelines, option 2 (1.2 million lux – hour/200 W/M²)] 
  • Freeze/thaw (-10°C to -20°C) 
  • Ambient /Above Ambient 

5) What are the Regulations for In-Package Stability Testing? 

The regulatory environment is nuanced and depends on the product and label claims. We explain OTC and cosmetic stability testing regulations here. 

Contact Our Stability Team to Discuss Your Project 

Our stability testing team works with hundreds of customers in the OTC, cosmetic, personal care, dietary supplements, and other industries. We design and conduct stability testing protocols for a full range of products, so reach out to discuss your next project 

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Topics: Cosmetic, OTC & Personal Care