The P-touch 2450DX is explicitly not on the compatibility list.
The original power supply is probably 9.5 volts. But 9V operation should not be a problem, it is within the tolerance.
I can't say whether the hollow plug fits, but from the pictures it seems to work. Power consumption in watts is also unclear.
It's probably worth a try.

Another possibility is this one:
Goobay Universal Power Supply
Please note: (!!) The P-Touch wants the +pole on the outside of the hollow plug (!!) (usually the +pole is on the inside).
You can see this when you look at the power connector on your P-Touch, it is printed on.