Certainly, all you have to do is remove that vulnerable tail and you're all set. Clipping it off with a pair of pliers should do the trick.
While the resilience of the head of the drop is legendary, it's only resilient relative to the normal properties of glass rather than being specifically highly resilient. The traditional test is to hit it with a hammer. (You're better off using the hammer if you want a weapon.) If you hit it hard enough from the head, it will still shatter leaving you holding a handful of glass.
There are ways of making glass resilient, but the very specific properties and specific vulnerability of Prince Rupert's drop is not the way to go.
What about toughened glass?
This is a similar concept to Prince Rupert's drop. The glass has a stress structure that gives it its strength, but that structure also gives it a weakness. The outer layer is in compression, and the interior is in tension. While you can batter away at it with your fists to no great effect, anything that damages the surface, such as an automatic centre punch, causes the entire pane to shatter into "safe" chunks. However this would allow you to use it for weapons until such time as your opponents discovered the counter.