How to make inflation last longer?

[flotation]

How long will a dextrose inflation last? Its my first time trying it and I have 250ml. My strategy is to do about a little more than 100 so I can do it in roughly 2 sessions. I am thinking about pumping it then leaving my cock ring on but I do not want it to get very uncomfortable. What is the best way to retain the dextrose inflation for as long as possible? And how long will it last