Stability of bupivacaine hydrochloride with diamorphine hydrochloride in an epidural infusion.
The stability of diamorphine (0.02 mg/ml as the hydrochloride) in 250 ml bupivacaine hydrochloride (0.15% wt/vol infusion) was studied by high pressure liquid chromatography at temperatures in the range 7 to 45 degrees C. Diamorphine hydrochloride was degraded by approximately 0.13% per day at 7 degrees C. No bupivacaine hydrochloride degradation was detectable during the study. The storage life of the combination at 7 degrees C, based on the lower 95% confidence limit of the time to 5% diamorphine hydrochloride degradation, was 14 days. The stability at 25 degrees C was adequate to allow transport and administration over 24 h at ambient temperature. Stability was also maintained for at least 24 hr at 32 and 45 degrees C. Infusion of the mixture with an ambulatory infusion pump which uses a standard polyvinyl infusion bag is therefore possible. A study of its compatibility with different infusion pump medication reservoirs was not undertaken. The drugs were also stable on frozen storage at -18 degrees C for up to 6 months.
Barnes
A R
AR
Pharmaceutical Sciences Institute, Aston University, Birmingham, UK.
Nash
S
S
D015360:Analgesia, Epidural / Q000592:standards; D000701:Analgesics, Opioid / Q000737:chemistry / Q000592:standards*; D000779:Anesthetics, Local / Q000737:chemistry / Q000592:standards*; D002045:Bupivacaine / Q000737:chemistry / Q000592:standards*; D002851:Chromatography, High Pressure Liquid; D004338:Drug Combinations; D004355:Drug Stability; D004356:Drug Storage; D003932:Heroin / Q000737:chemistry / Q000592:standards*; D007260:Infusion Pumps; D007700:Kinetics; D011143:Polyvinyl Chloride / Q000737:chemistry
D000701:Analgesics, Opioid; D000779:Anesthetics, Local; D004338:Drug Combinations; D003932:Heroin; D011143:Polyvinyl Chloride; D002045:Bupivacaine