Lorazepam stability in parenteral solutions for continuous intravenous administration.
OBJECTIVE
To determine the stability of lorazepam over a 24-hour period when prepared in polyvinyl chloride (PVC) bags at initial concentrations of 0.08 and 0.5 mg/mL.


METHODS
Each concentration was studied at room (21 degrees C) and refrigerator (4 degrees C) temperatures in dextrose 5% (D5W) and NaCl 0.9% solutions. Duplicate test solution admixtures were prepared for each lorazepam concentration, diluent, and temperature. At 0, 1, 4, 8, and 24 hours, duplicate samples were obtained for visual inspection, pH determination, and concentration determination by stability-indicating, reverse-phase HPLC analysis. Compared with baseline, peaks for lorazepam degradation products were not found on any of the study chromatograms.


RESULTS
In D5W and NaCl 0.9% solutions, lorazepam loss in excess of 10% by HPLC analysis occurred for concentrations of 0.08 and 0.5 mg/mL at 1 and 4 hours, respectively.


CONCLUSIONS
These data suggest that significant loss of lorazepam occurs as the probable result of sorption to PVC bags when admixed in both D5W and NaCl 0.9% solutions at 21 and 4 degrees C.
Hoey
L L
LL
Department of Pharmacy Practice, University of Minnesota, Minneapolis, USA.
Vance-Bryan
K
K
Clarens
D M
DM
Wright
D H
DH
Konstantinides
F N
FN
Guay
D R
DR
D002851:Chromatography, High Pressure Liquid; D004349:Drug Packaging; D004355:Drug Stability; D006993:Hypnotics and Sedatives / Q000008:administration & dosage / Q000737:chemistry*; D007275:Injections, Intravenous; D008140:Lorazepam / Q000008:administration & dosage / Q000737:chemistry*; D011143:Polyvinyl Chloride
D006993:Hypnotics and Sedatives; D011143:Polyvinyl Chloride; D008140:Lorazepam