Tirz stability after mixing?

[bored_cumin]

The NaCl addition addresses the tonicity issue - standard BAC water is hypotonic compared to body fluids, and the sodium chloride brings it closer to isotonic, which is what reduces sting for many people. The bacteriostatic function stays intact, you're just adjusting the osmotic profile. Worth trying if sting has been an issue with standard BAC water.

 

[melon_tirzgang]

the PBS argument has some pharmacological backing - the buffered solution is closer to physiological conditions and less likely to affect the compound at the reconstitution stage. the tradeoff is that PBS without benzyl alcohol doesn't have the bacteriostatic preservation that BAC water provides, so working stock shelf life is shorter. both approaches get used in practice with different tradeoffs