Table 1

Meropenem content and pH before and after storage at 32°C for 24 hours in different buffered diluents

Meropenem concentrationDiluentMean concentration (mg/mL) ± (95% CI)Meropenem remaining at T=24 hours, % ± (95% CI)pH
T=0T=24 hours at 32°CT=0T=24 hours at 32°C
25 mg/mL0.9% sodium chloride (unbuffered)26.71±(0.02)17.58±(0.10)65.838383±(0.35)7.807.56
1% citrate buffer at pH 6.022.08±(0.09)15.90±(0.04)72.00±(0.11)6.856.83
5% phosphate buffer at pH 6.024.62±(0.08)11.54±(0.02)46.86±(0.09)6.185.97
6.25 mg/mL0.9% sodium chloride (unbuffered)6.27±(0.02)5.18±(0.02)82.59±(0.23)7.687.51
0.3% citrate buffer at pH 7.06.25±(0.01)5.13±(0.01)82.05±(0.02)7.877.56
0.5% citrate buffer at pH 6.06.33±(0.02)5.24±(0.01)82.84±(0.29)6.937.01
1% citrate buffer at pH 6.06.19±(0.02)5.30±(0.02)85.60±(0.08)7.057.02
5% citrate buffer at pH 6.05.94±(0.03)2.64±(0.08)44.51±(1.29)6.156.00
5% phosphate buffer at pH 6.06.04±(0.05)2.50±(0.04)41.41±(0.55)5.905.76