night to day.A question often asked is whether shelf-life testing can be accelerated and the answer is ‘yes and no’. Storage at 38°C can, as a very general rule, increase normal deterioration by a factor of 4; hence 3 months in accelerated conditions represents 12 months under ambient conditions. However, the only real test of this is to carry out the accelerated test and compare it to a real-time study for a particular product, which means the correlation can only be demonstrated after the entire shelf-life has passed. Adding to the study, the effects of exposure to sunlight can complicate matters