Stability of lidocaine and ketamine diluted in 0.9% NaCl over time.
| Molecule | Concentration | Syringe | Mean % of initial concentration ±SD*% | |||
| 0 hour (initial concentration, mg/mL) | 6 hours | 24 hours | 48 hours | |||
| Lidocaine | 20 mg/mL | S1 | 100.00 (19,80)±2.14 | 101.42±0.19 | 98.01±1.93 | 99.49±1.14 |
| S2 | 100.00 (19.95)±0.80 | 101.90±0.33 | 101.45±0.33 | 99.94±0.20 | ||
| S3 | 100.00 (19.85)±0.34 | 100.76±0.86 | 101.71±0.82 | 102.24±0.26 | ||
| Ketamine | 2.5 mg/mL | S1 | 100.00 (2.45)±0.04 | 99.29±1.18 | 98.71±1.81 | 99.44±1.01 |
| S2 | 100.00 (2.46)±0.32 | 102.63±0.28 | 102.15±0.38 | 100.52±0.43 | ||
| S3 | 100.00 (2.47)±0.90 | 99.84±1.06 | 100.22±0.48 | 100.42±0.55 | ||
Drug concentrations in sample taken at time zero were designated at 100%.
*Samples were prepared in triplicate for each syringe.