Designed these TPU vial caps. 3ml, 5ml and 10ml, and 30ml. 5 and 10ml at least the vials that i have yours could be different, but mine uses the same measurement so i can print one cap and it fits both my 5ml and 10ml vials.  You can print this in PLA as well just change the settings but the measurements might be off with PLA filament since i honed it for TPU for flexibility. 

print very slow, make sure your tpu filament is dry and fans are turned off.