It won't buildup with once weekly use (technically it would, but the buildup would be bounded by sqrt(2) times your weekly dose, which I call "no buildup"). The dose concerns me more. Bicalutamide is extremely potent. It has AA effects in as low as 10mg oral daily in men, but a lower amount was not tested. So it very likely has AA effects well into the single digits, which amounts to <70mg weekly. 10mg/mL is very close to that number if you use multiple mL. Furthermore, if Bicalutamide has systemic AA effects at such low doses, that means we only need a fraction of that to create the same AA effect locally (where much higher concentrations can be achieved by topical means). That's why I don't recommend* concentrations higher than 1mg/mL (possibly lower, not sure yet). Furthermore, you can't dissolve 10mg/mL Bica in ethanol. The maximum is 1mg/mL, although you could achieve higher concentrations with DMSO. But again, not sure why you'd want to.
*Disclaimer: I don't recommend anything. Use at your own risk.