Physical, chemical, and microbiological stability study of diluted atropine eye drops

Table 1 Stability of atropine sulfate concentrations for each storage condition in unopened eyedropper bottles (mean ± 95% confidence interval; n = 6)

Set concentration and storage temperature	Initial concentration at Day 0 (mg/mL) (mean ± 95% CI)	Percentage of initial Day 0 measurement (mean ± 95% CI)
Set concentration and storage temperature	Initial concentration at Day 0 (mg/mL) (mean ± 95% CI)	Day 14	Day 28	Day 60	Day 90	Day 120	Day 180
0.1 mg/mL
5 °C	0.10 ± 0.32	99.00 ± 1.35	99.65 ± 1.21	98.89 ± 2.14	98.64 ± 1.75	98.45 ± 1.00	98.98 ± 1.19
25 °C	0.10 ± 0.32	99.98 ± 1.12	98.98 ± 0.41	99.13 ± 0.98	99.31 ± 0.98	98.78 ± 4.00	99.05 ± 3.71
1.0 mg/mL
5 °C	1.00 ± 0.41	99.01 ± 2.55	99.72 ± 2.15	99.23 ± 0.66	99.18 ± 1.95	98.06 ± 3.45	99.00 ± 1.59
25 °C	1.00 ± 0.41	100.02 ± 1.38	99.98 ± 0.74	99.65 ± 3.03	99.11 ± 3.09	98.13 ± 4.10	98.55 ± 7.03
2.5 mg/mL
5 °C	2.50 ± 0.01	99.91 ± 1.01	99.92 ± 1.55	99.84 ± 1.20	100.08 ± 1.88	98.66 ± 6.16	98.99 ± 0.99
25 °C	2.50 ± 0.01	100.40 ± 2.81	99.94 ± 2.54	99.75 ± 1.33	99.41 ± 4.44	99.15 ± 7.00	98.55 ± 5.33
5.0 mg/mL
5 °C	5.01 ± 0.02	98.96 ± 6.51	100.10 ± 1.66	103.37 ± 8.90	101.12 ± 3.33	99.85 ± 6.01	97.87 ± 3.68
25 °C	5.01 ± 0.02	100.05 ± 1.33	99.88 ± 7.00	99.57 ± 0.81	100.02 ± 1.11	98.07 ± 7.06	98.97 ± 0.67

ISSN: 2055-0294