Table 1. Screened cations and their aqueous solubility at 22°C.

	Approximate solubility (mg ml−1)	Amount needed (mg)†	Solution molarity [M]‡
Diltiazem hydro­chloride	720 ± 70§	312	1.44
(R,S)-Carnitine­nitrile chloride	1120 ± 106¶	486	5.64
(R)-Carnitine­nitrile chloride	1300 ± 200¶	564	6.54
(1S,2R)-(+)-Ephedrine hydro­chloride	257± 1¶	111	1.15
Trazodone hydro­chloride	38.5 ± 0.2¶	17	0.085

^†For screening 97 conditions.

^‡At 90% saturation.

^§Determined as described by Nievergelt et al. (2018 ▸).

^¶Value taken from the work by Nievergelt et al. (2018 ▸).