The product has acc. To label a 30-day shelf life. In my experience, a person needs about half a bottle per month (daily rinsing of lenses, cleaning of the container). According to half a bottle at the end of the month must be thrown away.
Note: The current product picture Amazon shows on the label on a Halbarkeit over 60 days. This figure does not correspond with the product supplied. There, the durability (as of July 2014) is specified as 30 days.