Stability of the productStability data on three batches of each strength of tablet manufactured at ≥10% of commercial scale stored for up to 12 months under long term conditions (25 °C / 60% RH), up to 12 months under intermediate conditions (30 °C / 75% RH) and for up to 6 months under accelerated conditions (40 °C / 75% RH) in line with the ICH guidelines was provided. The batches of Tagrisso were manufactured by the proposed commercial process although two smaller scale 40 mg batches were made at a different site. Otherwise, the batches are identical to and packed in the same primary packaging as those proposed for marketing. Identical studies on samples stored in bulk packaging (aluminium bag in rigid container) were also carried out. Samples were tested for according to the release specifications with the omission of the dose uniformity and the inclusion of a test for microbial quality at some time-points. The analytical procedures used are the same as for release and were shown to be stability indicating.No changes to any of the measured parameters were observed under any condition other than a small but notable increase in one specified degradation product. However, its level remained well within specification after 12 months and is predicted to do so, based on statistical analysis of the trends, over a 2 year period. Similar trends were observed for finished product stored in bulk packaging.In addition, one batch of each strength was exposed to light as defined in the ICH Guideline on Photostability Testing of New Drug Substances and Products. No significant changes to any of the measured parameters were observed, indicating that Tagrisso is not photosensitive. The batches were also stored under stressed conditions (50 oC / ambient RH and 40 oC / 75% RH / open container). The results indicate that Tagrisso is thermally stable but picks up up to 1 weight% water in a humid environment. However, this has no impact on other quality parameters or the product performance.Based on available stability data, the proposed shelf-life of 18 months without special storage conditions as stated in the SmPC (section 6.3) is acceptable.