Table 6.

Chromatographic (HPLC-UV) purity analysis of CS (2%) with HA (0.4%) eye drops stored in bottles and minims under controlled and uncontrolled conditions, and after exposure to the light, showing the area (P) of the observed peaks (P₁, P₂, P₃) and the percentage relative to the area of the main peak corresponding to the level of impurities of 0.1% (P_0.1% = 16862).

Storage Conditions	Package	Time, Months	Observed Peaks Outside the CS Main Peak				Sum of Impurities, %
			P1 tR = 2.8–3.6 min		P2 tR = 5.8–6.4 min
			P	%	P	%
40 °C/75% RH	Bottle	0	35650	0.21	69001	0.41	0.61
		6	31392	1.99	57993	0.34	2.33
	Minims	0	35650	0.21	69001	0.41	0.62
		3	486043	2.88	No		2.88
25 °C/60% RH	Bottle	0	35650	0.21	69001	0.41	0.61
		6	61142	0.36	48304	0.29	0.65
		9	35925	0.21	No		0.21
		12	28989	0.17	37973	0.22	0.39
	Minims	0	35650	0.21	69001	0.41	0.61
		6	73551	0.44	51080	0.30	0.74
		9	209457	1.24	No		1.24
		12	13879	0.08	No		0.08
2–8 °C	Minims	0	35650	0.21	69001	0.41	0.61
		6	43503	0.26	52962	0.31	0.57
		9	35936	0.21	50559	0.30	0.51
		12	11324	0.07	60556	0.36	0.44
Light exposure (250 W/m2; 1.2 × 106 lux·h)
	Package	Sample	P1 tR = 2.8–4.2 min		P2 tR = 5.8–6.4 min		Sum of impurities, %
			P	%	P	%
	Minimis	protected	35590	0.21	33639	0.20	0.41
		unprotected	336527	1.99	No		1.99

Note: t_R—retention time; P—area; P₁, P₂—impurities; No—not observed.