Table 4.
Stability of Ceftriaxone during Storage in Accufuser Elastomeric Infusion Device, Expressed as Percentage of Original Concentration Remaining (Mean ± SD)*
| Study Day |
Nominal 5 mg/mL |
Nominal 40 mg/mL |
||||||
|---|---|---|---|---|---|---|---|---|
|
D5W |
NS |
D5W |
NS |
|||||
| 23°C | 4°C | 23°C | 4°C | 23°C | 4°C | 23°C | 4°C | |
| Observed initial concentration (mg/L) | 5.65 ± 0.47 | 5.14 ± 0.29 | 5.10 ± 0.42 | 5.77 ± 0.85 | 42.14 ± 3.83 | 42.69 ± 0.22 | 42.44 ± 2.04 | 45.45 ± 1.99 |
| 1 | 97.0 ± 2.2 | 101.0 ± 4.3 | 98.7 ± 3.8 | 104.7 ± 14.5 | 97.8 ± 9.7 | 97.2 ± 0.7 | 96.7 ± 1.6 | 97.94 ± 3.2 |
| 2 | 94.5 ± 3.6 | 97.4 ± 1.6 | 93.3 ± 6.1 | 104.8 ± 11.9 | 95.8 ± 0.3 | 99.3 ± 4.6 | 94.5 ± 4.6 | 98.2 ± 3.1 |
| 4 | 92.6 ± 4.6 | 96.4 ± 0.7 | 92.6 ± 7.6 | 105.8 ± 15.6 | 95.6 ± 0.8 | 97.3 ± 5.1 | 95.1 ± 3.4 | 98.7 ± 5.8 |
| 7 | 89.2 ± 0.6 | 97.6 ± 8.2 | 91.0 ± 5.7 | 104.6 ± 12.8 | 87.0 ± 1.0 | 96.3 ± 2.0 | 88.7 ± 2.1 | 95.7 ± 2.4 |
| 14 | 86.1 ± 10.7 | 97.3 ± 4.1 | 84.5 ± 4.6 | 103.6 ± 13.1 | 69.7 ± 1.2 | 95.8 ± 2.4 | 77.7 ± 2.6 | 95.5 ± 3.0 |
| 21 | 94.3 ± 3.6 | 97.4 ± 13.4 | 91.0 ± 1.9 | 89.8 ± 3.7 | ||||
| Degradation rate† (%/day) | –1.09 | –0.22 | –0.99 | –0.22 | –2.15 | –0.35 | –1.51 | –0.41 |
| T–90% (days)‡ | 7.4 | 41.9 | 8.1 | 65.7 | 5.2 | 26.1 | 6.1 | 23.1 |
| Fastest degradation rate§ | ||||||||
| Lower limit of 95% CI (%/day) | –1.37 | –0.43 | –1.23 | –0.60 | –2.39 | –0.52 | –1.69 | –0.58 |
| T–90% (days) | 7.3 | 23.5 | 8.1 | 16.7 | 4.2 | 19.4 | 5.9 | 17.4 |
| Estimated % remaining with storage¶ | ||||||||
| 13 days at 4°C | 94.47 | 92.23 | 93.30 | 92.53 | ||||
| For 1 additional day at 23°C | 93.10 | 91.00 | 90.91 | 90.84 | ||||
CI = confidence interval, D5W = dextrose 5% in water, NS = normal saline (0.9% sodium chloride), SD = standard deviation.
Each value was based on duplicate determination of 3 samples. The percent remaining was based on the observed concentration on day 0 (100%).
The degradation rate was determined by linear regression of the percent remaining on each study day.
T–90% is the time for the concentration to decline by 10% (i.e., time to reach 90% of initial concentration), as determined from the degradation rate.
Fastest degradation rate and T–90% were based on the lower 95% confidence limit of the regression-determined slope.
Using the fastest observed degradation rates determined by regression (95% CI), calculations were completed for a solution stored in an Accufuser elastomeric infusion device for 13 days, followed by storage for an additional 24 h at room temperature (23ºC).