In the buffer with pH=6.8 (Figure ), there is an expected decrease in dissolution rate as a result of the shift in the protonation equilibrium. Under these conditions, we have observed the following trend in the solubility, in increasing order: HTBZ-HFU, HTBZ_HMA (LAG), HTBZ-SAC, HTBZ-HOX. We note that although the solubilities of the salts at pH=6.8 are markedly reduced, they are still 2-3 times higher than the solubility of pure TBZ.