Table 3.

(A) Physicochemical evaluations of Zn-Glycine gel formulation; (B) Physicochemical evaluations of Zn-Histidine gel formulation; (C) Physicochemical evaluations of placebo gel formulation.

(A)
Stability Testing Week	ZnGly Gel
	Color, Odor	pH *	Density * [g/cm3]	Viscosity * [cP], (R4, 2 RPM)
0	slightly yellowish, no odor	5.35 ± 0.01 a**	-	-
1	no changes	5.35 ± 0.01 a	1.0046 ± 0.0001 d	79,478 ± 1376 a,b
2	no changes	5.34 ± 0.01 a	1.0045 ± 0.0001 a	82,332 ± 1094 b
3	no changes	5.27 ± 0.02 b,c	1.0044 ± 0.0001 a	77,658 ± 1323 a
4	no changes	5.26 ± 0.02 b	1.0032 ± 0.0001 b	77,233 ± 1276 a
5	no changes	5.30 ± 0.01 c	1.0044 ± 0.0001 a	76,964 ± 1354 a
6	no changes	5.25 ± 0.02 b	1.0042 ± 0.0001 c	77,796 ± 1083 a
(B)
Stability Testing Week	ZnHis Gel
	Color, Odor	pH *	Density * [g/cm3]	Viscosity * [cP], (R5, 2 RPM)
0	slightly yellowish, no odor	5.35 ± 0.02 a**	-	-
1	no changes	5.36 ± 0.01 a	0.9788 ± 0.0001 a	157,724 ± 2742 a
2	no changes	5.35 ± 0.01 a	0.9836 ± 0.0001 b	154,249 ± 2866 a
3	no changes	5.35 ± 0.01 a	0.9786 ± 0.0001 c	152,138 ± 2435 a
4	no changes	5.33 ± 0.02 a	0.9894 ± 0.0001 d	154,403 ± 2009 a
5	no changes	5.40 ± 0.01 b	0.9928 ± 0.0001 e	153,519 ± 2289 a
6	no changes	5.40 ± 0.01 b	0.9872 ± 0.0001 f	155,302 ± 2162 a
(C)
Stability Testing Week	Placebo Gel
	Color, Odor	pH *	Density * [g/cm3]	Viscosity * [cP], (R2, 30 RPM)
0	slightly yellowish, no odor	5.31 ± 0.02 a**	-	-
1	no changes	5.35 ± 0.01 b	1.0136 ± 0.0001 a	971.7 ± 14 a
2	no changes	5.32 ± 0.01 b	1.0136 ± 0.0001 a	1034.6 ± 13 b,c
3	no changes	5.25 ± 0.02 c	1.0136 ± 0.0001 a	1089.7 ± 15 d
4	no changes	5.27 ± 0.02 c	1.0118 ± 0.0001 b	1051.2 ± 12 c
5	no changes	5.30 ± 0.02 a	1.0116 ± 0.0001 b	979.6 ± 12 a
6	no changes	5.29 ± 0.02 a,c	1.0106 ± 0.0001 c	995.2 ± 11 a

* Values expressed as mean ± SD of triplicate measurements (n = 3). ** Means indicated with the same letter within each column are not statistically different (Tukey’s test; p ≤ 0.05).