Table 3.

Dissolution rates and solubility at 18 °C in MeCN in the case of Nefiracetam FI, NCA, NOA, and NZC.

Solid Forms	Dissolution Rate * (mM/s)/Time (min)	Solubility (mM, 18 °C)	Solubility Product (Ks, 18 °C)	pKs
Nefiracetam FI	969/0.1	290.83 (±10.97)	/	/
NCA	323/0.5	322.87 (±4.32)	1.35 × 10−1	0.87
NOA	538/0.2	215.03 (±1.03)	3.98 × 10−2	1.40
NZC	64/0.2	25.45 (±0.63)	6.48 × 10−4	3.19

* Dissolution rates correspond to the rate calculated when half the solubility is reached, with the corresponding time also given.