If you can't get DW then chemists should stock Pure Water for their prescription medications, that's probly the best you can do. Pure Water is good enough. Let's face it, not everyone has access to DW or the purest water so no problem, they have to make do with the best they can find that's all. DW is preferable but hey, if you can't get it, you can't get, so go for the next best thing.