Table 8.

NAC + 62.5 µg·mL⁻¹ zinc gluconate stability study, 25 ± 2 °C ambient storage conditions.

	T0	1 Day	2 Days	3 Days	4 Days	7 Days	8 Days	R 2,4	p Value 5
NAC content ± S.D. 1	22.10 ± 0.20	21.93 ± 0.18	21.40 ± 0.15	21.58 ± 0.08	21.65 ± 0.10	21.17 ± 0.08	21.23 ± 0.18	0.75	<0.02
% NAC dimer ± S.D. 2	0.27 ± 0.03	0.29 ± 0.03	0.34 ± 0.03	0.38 ± 0.04	0.42 ± 0.05	0.50 ± 0.04	0.53 ± 0.04	0.99	<0.001
Osmolality 3	541	540	580	584	569	540	538	0.06	NS 6
pH	5.29	5.29	5.31	5.32	5.33	5.41	5.43	0.96	<0.001
Sterility	Sterile	ND	ND	ND	Sterile	ND	Sterile
Endotoxins 4	0.1<	ND	ND	ND	0.1<	ND	0.1<
Visible particles	none	none	none	none	none	none	none

¹ expressed as the mean value of triplicate analysis, in mg·mL⁻¹; ² expressed as the mean value of triplicate analysis; ³ expressed in mOsm.kg⁻¹; ⁴ expressed in IU.mL⁻¹; ⁴ coefficient of determination; ⁵ correlation coefficient test significance; ⁶ not statistically significant.