Table 3 pH change of atropine solutions after storage (mean ± standard deviation; n = 6)
From: Physical, chemical, and microbiological stability study of diluted atropine eye drops
Set concentration and storage temperature | Initial pH at Day 0 (mean ± SD) | pH values (mean ± SD) | |||||
|---|---|---|---|---|---|---|---|
Day 14 | Day 28 | Day 60 | Day 90 | Day 120 | Day 180 | ||
0.1 mg/mL | |||||||
5 °C | 5.90 ± 0.40 | 5.91 ± 1.09 | 5.84 ± 0.15 | 5.77 ± 1.63 | 5.69 ± 1.18 | 5.61 ± 1.16 | 5.61 ± 1.09 |
25 °C | 5.92 ± 1.06 | 5.80 ± 1.95 | 5.70 ± 1.84 | 5.66 ± 1.27 | 5.59 ± 1.51 | 5.61 ± 1.99 | |
1.0 mg/mL | |||||||
5 °C | 5.88 ± 0.30 | 5.88 ± 0.99 | 5.74 ± 0.85 | 5.74 ± 1.33 | 5.65 ± 0.14 | 5.60 ± 0.86 | 5.58 ± 0.99 |
25 °C | 5.88 ± 1.05 | 5.70 ± 0.95 | 5.73 ± 0.74 | 5.65 ± 0.77 | 5.60 ± 0.08 | 5.57 ± 0.70 | |
2.5 mg/mL | |||||||
5 °C | 5.88 ± 0.31 | 5.88 ± 0.31 | 5.74 ± 1.37 | 5.74 ± 0.79 | 5.65 ± 0.12 | 5.60 ± 0.41 | 5.58 ± 0.39 |
25 °C | 5.88 ± 0.05 | 5.70 ± 0.61 | 5.70 ± 0.94 | 5.65 ± 0.74 | 5.60 ± 0.12 | 5.57 ± 0.32 | |
5.0 mg/mL | |||||||
5 °C | 5.88 ± 0.41 | 5.88 ± 0.11 | 5.74 ± 0.39 | 5.71 ± 0.93 | 5.70 ± 0.44 | 5.68 ± 0.15 | 5.68 ± 0.11 |
25 °C | 5.88 ± 0.47 | 5.69 ± 0.55 | 5.68 ± 0.19 | 5.67 ± 0.32 | 5.68 ± 0.45 | 5.68 ± 0.66 | |