Stress testing product

More recently, test products were created of a blend of PMMA with a phenyl-substituted methacrylate these products have a glass-transition temperature of around 125°C, a significantly reduced water absorption compared to pure PMMA of about 0.32%, but also a higher birefringence (a stress-optic coefficient of 5.2 X 10 , compared with 0.3 X 10 for PMMA and 6.8 x 10 for BPA-PC). 

Design validation may take the form of qualification tests which stress the product up to and beyond design limits - beta tests where products are supplied to several typical users on trial in order to gather operational performance data, performance trials, and reliability and maintainability trials where products are put on test for prolonged periods to simulate usage conditions. 

Several stress tests were performed before scale-up. If the asymmetric deprotonation of 19 was carried out at -55 to -45 °C instead of-70 to -60 °C, product 5 from the coupling reaction was obtained in a significantly lower 85% ee although the yield was not affected (83%). An overcharge of (-)-sparteine provided only a marginal improvement in the ee of product 5 for example, l.lequiv of sparteine provided a 93% ee while 0.90 equiv of sparteine gave a slightly eroded 89% ee. 

Stress Testing (drug product) — Studies undertaken to assess the effect of severe conditions on the drug product. Such studies include photostability testing (see ICH Q1B) and specific testing of certain products (e.g., metered dose inhalers, creams, emulsions, refrigerated aqueous liquid products). 

Many validation personnel understand the need for and the benefits of performing trials and stress testing, but do their companies share their understanding While many may have a solid understanding, they seldom share the desire to fund prevalidation trials. This is true because many of these trials cannot be simulated and therefore performed with actual product. 

Stress testing is the main tool that is used to predict stability problems, develop analytical methods, and identify degradation products and pathways. Since there are no detailed regulatory guidelines that describe how to carry out stress testing studies (nor has there ever been a textbook or reference book devoted to the subject), stress testing has evolved into an artful science that is highly dependent on the experience of the company... 

Stress testing is conducted to provide data on forced decomposition products and decomposition mechanisms for the drug substance. 

The ICH definition of stress testing for the drug product is shown below (7) ... 

Baertschi SW. The Role of Stress Testing in Pharmaceutical Product Development, presented at the American Association of Pharmaceutical Scientists Midwest Regional Meeting, Chicago, IL, May 20, 1996. 

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