. 2022 Mar 29;11(4):458. doi: 10.3390/antibiotics11040458

Table 3.

Stability of antibiotics in polyisoprene elastomeric devices for use in OPAT at 37 °C measured by HPLC.

			Mean % of Initial Concentration ± RSD *
Antibiotic	Conc.	Solvent NS/D5W	T0 h	T6 h	T8 h	T12 h	T24 h	T48 h
Aztreonam	50 mg/mL	NS **	100.0 ± 1.97	-	-	-	102.5 ± 3.39	100.2 ± 2.17
Aztreonam	50 mg/mL	D5W ***	100.0 ± 1.64	-	-	-	101.7 ± 1.67	95.3 ± 2.96
Cefazolin	50 mg/mL	NS	Unstable, precipitate formation during pre-study
Cefazolin	50 mg/mL	D5W	Unstable, precipitate formation during pre-study
Cefepim	50 mg/mL	NS	100.0 ± 1.43	93.2 ± 2.00	-	-	83.3 ± 2.28	59.5 ± 2.21
Cefiderocol	Unrealized in elastomeric device
Cefotaxime	25 mg/mL	NS	Unstable, colour change after 6 h during pre-study
Cefotaxime	25 mg/mL	D5W	Unstable, colour change after 6 h during pre-study
Cefoxitine	25 mg/mL	NS	Unstable, Colour change after 12 h during pre-study
Cefoxitine	25 mg/mL	D5W	Unstable, Colour change after 12 h during pre-study
Ceftazidime	25 mg/mL	NS	100.0 ± 3.22	-	95.2 ± 1.56	-	85.6 ± 2.24	-
Ceftazidime	25 mg/mL	D5W	100.0 ± 2.94	-	94.8 ± 3.29	-	77.5 ± 1.94	-
Ceftazidime	25 mg/mL	NS	100.0 ± 3.35	-	-	92.2 ± 2.86	82.3 ± 2.28	66.3 ± 1.90
Ceftazidime	25 mg/mL	D5W	100.0 ± 7.35	-	-	86.2 ± 6.54	75.4 ± 7.53	58.1 ± 8.56
Avibactam	6.25 mg/mL	NS	100.0 ± 4.59	-	-	98.4 ± 4.08	96.5 ± 2.95	93.9 ± 2.95
Avibactam	6.25 mg/mL	D5W	100.0 ± 7.81	-	-	95.4 ± 6.92	93.9 ± 7.46	90.3 ± 8.35
Ceftozolane	25 mg/mL	NS	100.0 ± 1.80	-	100.0 ± 1.20	-	91.8 ± 0.95	81.4 ± 3.67
Ceftozolane	25 mg/mL	D5W	100.0 ± 0.99	-	97.5 ± 0.85	-	89.3 ± 2.11	81.7 ± 6.02
Tazobactam	12.5 mg/mL	NS	100.0 ± 2.08	-	104.6 ± 1.47	-	109.2 ± 1.33	116.7 ± 3.02
Tazobactam	12.5 mg/mL	D5W	100.0 ± 0.99	-	103.1 ± 0.82	-	109.5 ± 1.33	116.6 ± 1.83
Cloxacillin	50–100 mg/mL	NS	Unstable, precipitate formation during pre-study
Cloxacillin	50–100 mg/mL	D5W	Unstable, precipitate formation during pre-study
Meropenem	Unrealized in elastomeric device
Piperacillin	66.7 mg/mL	NS	Unstable, precipitate formation during pre-study
Piperacillin	66.7 mg/mL	D5W	Unstable, precipitate formation during pre-study
Piperacilline	66.7 mg/mL	NS	100.0 ± 2.17	-	98.5 ± 0.46	-	93.6 ± 1.06	85.7 ± 1.92
Piperacilline	66.7 mg/mL	D5W	100.0 ± 0.74	-	97.9 ± 0.87	-	93.6 ± 0.60	84.1 ± 0.17
Tazobactam	8.3 mg/mL	NS	100.0 ± 2.26	-	98.9 ± 0.53	-	97.0 ± 0.93	96.2 ± 1.58
Tazobactam	8.3 mg/mL	D5W	100.0 ± 0.78	-	98.7 ± 0.90	-	98.2 ± 0.55	95.8 ± 0.25
Temocillin	25 mg/mL	NS	100.0 ± 2.37	-	-	-	92.6 ± 2.95	80.4 ± 2.84
Temocillin	25 mg/mL	D5W	100.0 ± 2.36	-	-	-	87.5 ± 2.23	78.8 ± 2.61
Vancomycin	37.5 mg/mL	NS	100.0 ± 2.06	-	-	-	97.9 ± 2.91	98.3 ± 3.26
Vancomycin	37.5 mg/mL	D5W	100.0 ± 2.70	-	-	-	101.0 ± 1.61	103.3 ± 1.54

* RSD: Relative standard deviation; ** NS: Normal Saline, *** D5W: Dextrose 5%.