We had trouble getting enough Boron to the brain and heart without Asparatates. If difficult to find use Borax instead.
Boric Acid (Borax) will convert to 11% boron trioxide, aka as an expensive Laundry whitener booster.
Boron trioxide will not bind 90 times its molecular weight in radiation as some of the other Borons do.
IMO if you can't get a good quality product use Drug Store Boron and Borax.