I have looked everywhere and only have gotten expiration date of Timolol Maleate not patency of eye drops once opened in the UK... they say good only for 4 weeks once opened in multidose container... have e-mailed the company and my Pharmacist said it is good for 3 months... but unable to verify this info... waiting for MD from this site to answer my question as I asked and submitted pay pal payment don't know when I will get my answer... can anyone help with this question not in the leaflet that comes with the eye drops... Thank you