Table 5.

Results of the analysis of the susceptibility of compounds 2 and 6 to environmental factors (acidic, alkaline, neutral, and oxidising conditions), along with the ICH classification stress test.

Environment	Conditions	C0, μg/mL	Ct, μg/mL	% Decomposition	ICH Classification
2
HCl	0.1 M, 90 °C, 16 h	61.3	5.0	91.8
HCl	0.01 M, 40 °C, 8 h	60.0	33.7	43.8	very unstable
NaOH	0.1 M, 90 °C, 16 h	61.3	0	100
NaOH	0.01 M, 25 °C, 2 h	60.0	0	100	extremely unstable
H2O	90 °C, 24 h	61.3	46.3	24.4	unstable
H2O2	1%, 30 min	30.0	29.9	<0.5
H2O2	3%, 24 h	30.0	29.8	<0.5
H2O2	10%, 24 h	30.0	30.1	<0.5	practically stable
6
HCl	0.1 M, 90 °C, 16 h	66.9	1.5	97.8
HCl	0.01 M, 40 °C, 8 h	60.0	49.3	17.8	very unstable
NaOH	0.1 M, 90 °C, 16 h	66.9	0	100
NaOH	0.01 M, 25 °C, 2 h	60.0	0	100	extremely unstable
H2O	90 °C, 24 h	66.9	50.9	23.9	unstable
H2O2	1%, 30 min	30.0	29.7	<0.5
H2O2	3%, 24 h	30.0	29.9	<0.5
H2O2	10%, 24 h	30.0	30.0	<0.5	practically stable