Droperidol stability in intravenous admixtures

The stability and compatibility of droperidol in small-volume i.v. admixtures was assessed. Droperidol was diluted to a nominal concentration of 1 mg/50 ml in 5% dextrose injection, 0.9% sodium chloride injection, and lactated Ringer's injection in type I glass bottles and polyvinyl chloride bags. Triplicate samples of each admixture were stored under continuous illumination at 27 +/- 2 degrees C. Specimens from each sample were tested by spectrophotometric assay at intervals during storage periods of up to 272 hours for admixtures containing 5% dextrose injection and 0.9% sodium chloride injection and up to 168 hours for admixtures containing lactated Ringer's injection. Between 48 and 168 hours of storage, a 7% increase was observed in droperidol concentration in 0.9% sodium chloride admixtures in polyvinyl chloride bags. A 24% decrease in droperidol concentration in lactated Ringer's admixtures in polyvinyl chloride bags between 24 and 168 hours was attributed to sorption of droperidol by the plastic container. In all admixtures except those containing lactated Ringer's injection in polyvinyl chloride bags, droperidol concentrations throughout the storage period were within 10% of initial concentrations. Droperidol is stable in the admixtures studied for 7 to 10 days in glass bottles. In polyvinyl chloride bags, concentrations in admixtures containing 5% dextrose injection and 0.9% sodium chloride injection are stable for seven days, but concentrations decrease significantly in lactated Ringer's admixtures.