I see how you could do it.

If you had 33 different types of nano-particles and each type had a unique resonate frequency you could build a 33 bit binary string.

This would give you about 10 billion combinations.

When you make the batch, you either add or don't each frequency per each dose.

Every dose would be a unique 33 bit number.

You can make a simple passive resonator with an inductive connected bifilar coil.

https://en.wikipedia.org/wiki/Bifilar_coil

Then just nano size it.

This may require a feature on 5G.