Every product registration must contain proof of product stability under a range of storage conditions, guidance on which is given in the ICH Harmonised Tripartite Guidelines “Stability testing of new drug Substances and products Q1A(R2)”. Storage conditions for a study will depend upon the product type, its recommended storage temperature (e.g. refrigerated) and the markets into which the product is to be sold.
For an ambient product, the general approach is three fold: samples are tested using stability indicating assays at the initial time point and then at 3, 6, 9 and 12 months. We are also able to offer 18, 24 and 36 months testing for shelf life assessment.
The stability indicating assays will measure the level of active ingredient with a <5% drop considered a significant loss of activity. Physical attributes such as colour, phase separation, caking, hardness and pH are also assessed.The results of the temperature and humidity storage conditions will usually be reported within 10 working days from pull of samples after stability timepoint.
From a microbiological view, we would also consider the preservative activity in multi-dose formulations. Sterility and bacterial endotoxin levels in parenteral products as well as microbial limits testing including Total Aerobic Microbial (TAMC) counts, Total Yeast and Mould (TYMC) counts, and absence of specified microorganisms testing may also be required depending on the product.
At Wickham Micro we have two large and two medium purpose built stability cabinets. These cabinets have undergone full qualification and are continually monitored for temperature and humidity; this is done via a hard wired system which is alarmed and monitored 24/7 with any temperature or humidity changes triggering an alert to our dedicated staff.