Shelf life limiting attribute

Shelf life limiting attribute (SLLA) An attribute which will breach its limit when stored at fixed conditions at a point predetermined by CSA (s) (e.g., degradation product... and would be measured on stability). 

An approach for analyzing data of a quantitative attribute that is expected to change with time is to determine the time at which the 95% one-sided confidence limit for the mean curve intersects the acceptance criterion. If analysis shows that the batch-to-batch variability is small, it is advantageous to combine the data into one overall estimate by applying appropriate statistical tests (e.g., p-values for level of significance of rejection of more than 0.25) to the slopes of the regression lines and zero-time intercepts for individual batches. If it is inappropriate to combine data from several batches, the overall shelf life should be based on the minimum time a batch can be expected to remain within the acceptance criteria. 

If a formulation uses high-intensity sweeteners, preservatives or colours, it is critical to ensure that the levels of these materials in the product do not exceed the statutory limits. Although the fortification of some products has been common practice for many years, the addition of vitamins to soft drinks has only recently become common. In the United Kingdom, this is likely to be attributable in part to the phenomenally successful launch of the Sunny Delight brand, which has prompted the launch of a wide range of me too products. Here again there is an analytical need to ensure that the vitamin levels claimed on the label ar e met at the end of shelf life. 

An appropriate approach to retest period or shelf-life estimation is to analyze a quantitative attribute by determining the earliest time at which the 95% confidence limit for the mean around the regression curve intersects the proposed acceptance criterion. 

---