Chemical and visual stability of amphotericin B in 5% dextrose injection stored at 4 degrees C for 35 days.

The chemical and visual stability of amphotericin B in 5% dextrose injection under refrigeration was assessed. Three admixtures of amphotericin B 0.1 mg/mL in 5% dextrose injection and three admixtures of amphotericin B 0.25 mg/mL in 5% dextrose injection were aseptically prepared in polyvinyl chloride (PVC) bags. Immediately after preparation (at time zero), six 5-mL samples were aseptically transferred from each admixture to sterile collection tubes. Three of the samples from each admixture were quick-frozen for later assay by stability-indicating high-performance liquid chromatography (HPLC), and the other three were immediately assessed for pH. Each of the six admixtures was also assessed visually under fluorescent light and 2x magnification for color change, turbidity, gas evolution, and precipitation. The admixtures were stored in PVC bags at 4 degrees C and protected from light. Six 5-mL samples were withdrawn from each admixture at 10, 21, and 35 days. Three of the samples from each admixture were assessed for pH, and three were quick-frozen for subsequent HPLC assay. There was no substantial loss or deterioration of amphotericin B during the 35-day study. At no time was the mean concentration of amphotericin B in the samples less than 96.4% of the concentrations at time zero for the 0.1-mg/mL samples or less than 96.6% of the time zero concentrations for the 0.25-mg/mL samples. There were no appreciable changes in pH, and there was no visual evidence of instability in any of the samples.(ABSTRACT TRUNCATED AT 250 WORDS)     

Stability of mitomycin admixtures

The stability of mitomycin in admixtures for continuous intravenous infusion was studied. Mitomycin was reconstituted and diluted to 50 micrograms/mL in polyvinyl chloride minibags containing 5% dextrose injection 50 mL or 0.9% sodium chloride injection 50 mL. Additional mitomycin admixtures were reconstituted with a buffer solution containing monobasic and dibasic sodium phosphate; these were diluted with 5% dextrose injection only. Admixtures were stored at room temperature (27-30 degrees C) and refrigerated temperature (5 degrees C) for 120 days. Mitomycin concentrations in each admixture were tested by high-performance liquid chromatography (HPLC) immediately after admixture and at intervals during storage. Ultraviolet spectra were determined at the same time as HPLC analysis, and the admixtures were visually inspected and tested for pH. Mitomycin concentrations decreased rapidly in the unbuffered admixtures; after 12 hours at room temperature, less than 26% of the drug remained in the dextrose admixture. When the unbuffered admixtures were refrigerated for 12 hours, the mitomycin concentrations decreased 10% in the sodium chloride admixtures and 33% in the dextrose admixtures; after 24 hours, the percentages of drug loss were 23% and 42%, respectively. Mitomycin concentrations in the buffered admixtures showed no substantial decrease during 120 days at 5 degrees C. At room temperature, concentrations decreased 10% after 15 days. When the admixture is buffered to a pH of approximately 7.8, mitomycin is stable in 5% dextrose injection for up to 15 days at room temperature and at least 120 days at 5 degrees C. Unbuffered mitomycin admixtures should not be stored or administered by prolonged i.v. infusion.     

Stability of ganciclovir sodium in 5% dextrose injection and in 0.9% sodium chloride injection over 35 days.

The stability of ganciclovir 1 and 5 mg/mL in 5% dextrose injection and in 0.9% sodium chloride injection was studied at 25 degrees C and 5 degrees C over 35 days. Ganciclovir (as the sodium salt) was added to 120 polyvinyl chloride bags containing either 5% dextrose injection or 0.9% sodium chloride injection to attain ganciclovir concentrations of 1 and 5 mg/mL. Thirty bags were prepared for each combination of drug concentration and i.v. solution. Half of the bags in each group were stored at 25 degrees C; the other half were stored at 5 degrees C. Samples withdrawn from all 120 bags immediately after preparation were frozen for later determination of initial concentration. At 7, 14, 21, 28, and 35 days after preparation, approximately 5-mL samples representing each test condition were withdrawn for analysis. The samples were visually examined, tested for pH, and assayed by high-performance liquid chromatography. There was no significant loss of ganciclovir under any of the study conditions over 35 days. All solutions were clear throughout the study period. The pH decreased slightly in both diluents at both ganciclovir concentrations but did not deviate from the manufacturer's range (9-11). Admixtures containing ganciclovir 1 and 5 mg/mL (as the sodium salt) in 5% dextrose injection and 0.9% sodium chloride injection were stable in polyvinyl chloride bags stored at 25 degrees C and 5 degrees C for 35 days.     

Compatibility of cefoperazone sodium and furosemide in 5% dextrose injection

The compatibility of cefoperazone sodium and furosemide in 5% dextrose injection stored at two temperatures was studied. Cefoperazone sodium and furosemide were added to 5% dextrose injection to achieve a cefoperazone concentration of 10 mg/mL and a furosemide concentration of 0.2 mg/mL. The admixture was stored in 100-mL vented i.v. containers in the dark under refrigeration (4 degrees C) and at room temperature (25 degrees C); three containers were stored at each temperature. A 1-mL sample was taken from each i.v. container immediately after preparation and after 1, 2, 5, 10, 15, 20, and 25 days to be inspected visually, checked for pH value, and analyzed by a stability-indicating high-performance liquid chromatographic method. No color change or precipitation was observed in any sample at any time during the study. More than 95% of the initial concentrations of both drugs remained for five days at 4 degrees C but for only two days at 25 degrees C. Cefoperazone sodium was somewhat more stable than furosemide under the same storage conditions for 25 days; however, less than a 2% difference between the drugs was noted. Under the conditions of this study, cefoperazone sodium 10 mg/mL and furosemide 0.2 mg/mL in admixtures in 5% dextrose injection are stable for only two days at 25 degrees C and five days at 4 degrees C.     

Compatibility of cefoperazone sodium and cimetidine hydrochloride in 5% dextrose injection

The compatibility of cimetidine hydrochloride and cefoperazone sodium in 5% dextrose injection stored at two temperatures was studied. Cimetidine hydrochloride and cefoperazone sodium were reconstituted or diluted with 5% dextrose injection to form an admixture with a cimetidine concentration of 2 mg/mL and a cefoperazone concentration of 5 mg/mL. The admixture was stored in 100-mL vented i.v. containers in the dark at 4 and 25 degrees C; three containers were stored at each temperature. A 2-mL sample was taken from each container after 0.5, 0.75, 1, 6, 12, 24, and 48 hours of storage and visually inspected, tested for pH, and assayed by a stability-indicating high-performance liquid chromatographic method. Triplicate studies were done for each storage condition. At both temperatures, drug concentrations varied by less than 5% during the study period. No color change, precipitation, or cloudiness was observed for any of the solutions under any of the storage conditions. Cefoperazone sodium 5.0 mg/mL and cimetidine hydrochloride 2.0 mg/mL in admixtures in 5% dextrose injection are stable for 48 hours at 4 and 25 degrees C.     

Stability of ranitidine in intravenous admixtures stored frozen, refrigerated, and at room temperature

The stability of ranitidine in concentrations of 0.5, 1.0, and 2.0 mg/mL in admixtures with commonly used i.v. fluids was studied. The admixture vehicles were 0.9% sodium chloride, 5% dextrose, 10% dextrose, 5% dextrose and 0.45% sodium chloride, and 5% dextrose with lactated Ringer's (DLR) injections in polyvinyl chloride bags. Three bags were prepared for each test solution and stored under each of the following conditions: seven days at room temperature (23 +/- 1 degrees C) in normal laboratory lighting, 30 days at 4 degrees C, and 60 days at -20 degrees C followed by either seven days at room temperature (in light) or 14 days at 4 degrees C. Ranitidine content was determined by high-performance liquid chromatography at several intervals. Color, clarity, and pH were also examined. Ranitidine concentrations remained greater than or equal to 90% of initial concentrations under all storage conditions except in the frozen DLR admixtures. Drug loss in the DLR admixtures was greatest at the lower ranitidine concentrations. The only visual changes were yellow color in the thawed DLR admixtures and those containing ranitidine 2.0 mg/mL in 5% dextrose and 0.45% sodium chloride. Slight increases in the pH of some admixtures were noted. Ranitidine is stable for seven days at room temperature and 30 days at 4 degrees C at all concentrations and in all vehicles studied. At the studied concentrations, the drug is stable in admixtures frozen for 60 days and stored for seven days at room temperature or 14 days refrigerated, except in DLR admixtures; these admixtures should not be stored frozen.     

Stability of intravenous admixtures of aztreonam and cefoxitin, gentamicin, metronidazole, or tobramycin

The stability of aztreonam and cefoxitin, gentamicin, metronidazole, or tobramycin in intravenous admixtures containing aztreonam and one of the other drugs was studied. Admixtures of aztreonam and gentamicin, aztreonam and tobramycin, and aztreonam and cefoxitin were each prepared in four different concentrations in both 0.9% sodium chloride injection and 5% dextrose injection. Admixtures of aztreonam and metronidazole were prepared in two different concentrations using a commercially available solution of metronidazole 5 mg/mL in a phosphate-citrate buffer. One of each of these admixtures was stored at 25 degrees C for 48 hours and at 4 degrees C for seven days. At various storage times, 1-mL samples of the admixtures were tested for pH and assayed using high-performance liquid chromatography or fluorescence polarization immunoassay. The pH of all admixtures except admixtures of aztreonam and cefoxitin decreased only slightly during storage. Concentrations of aztreonam and tobramycin under both storage conditions decreased by less than 10%. Concentrations of cefoxitin and aztreonam decreased by more than 10% at 25 degrees C, and concentrations of gentamicin decreased by more than 10% under both storage conditions. Visual inspection of admixtures of aztreonam and metronidazole revealed an incompatibility between the two drugs, as evidenced by the appearance of a cherry-red color. Admixtures of aztreonam 10 and 20 mg/mL and tobramycin 0.2 and 0.8 mg/mL in 5% dextrose injection or 0.9% sodium chloride injection are stable for 48 hours at 25 degrees C or seven days at 4 degrees C. Admixtures of aztreonam 10 and 20 mg/mL and gentamicin 0.2 and 0.8 mg/mL in 5% dextrose injection or 0.9% sodium chloride injection are stable for eight hours at 25 degrees C and 24 hours at 4 degrees C. Admixtures of aztreonam 10 and 20 mg/mL and cefoxitin 10 and 20 mg/mL in 5% dextrose injection or 0.9% sodium chloride injection are stable for 12 hours at 25 degrees C and seven days at 4 degrees C. Aztreonam and metronidazole should be administered separately.     

Stability of vancomycin hydrochloride in 5% dextrose and 0.9% sodium chloride injections

The stability of vancomycin hydrochloride mixed with 5% dextrose and 0.9% sodium chloride injections was studied. Vancomycin hydrochloride powder was mixed with each of the two diluents in final concentrations of 5 mg/mL. Duplicate samples of each admixture were divided into four parts and stored at 24 degrees C in glass and in plastic i.v. bags for 17 days and at 5 degrees C and -10 degrees C in glass for 63 days. To additional samples, hydrochloric acid or phosphate buffer was added; these were stored at 24 degrees C for 17 days. At various storage times, clarity and pH of the samples were recorded and vancomycin concentrations were measured in triplicate by high-performance liquid chromatography. Except for the buffered samples, all solutions remained clear and pH was unchanged. Vancomycin concentrations decreased less than 6% during 17 days at room temperature. In the refrigerated and frozen samples, vancomycin concentrations decreased less than 1% throughout the study. Vancomycin hydrochloride is stable in admixtures with 5% dextrose injection and 0.9% sodium chloride injection for 17 days at 24 degrees C and for 63 days at 5 degrees C and -10 degrees C.     

Stability of amrinone and digoxin, procainamide hydrochloride, propranolol hydrochloride, sodium bicarbonate, potassium chloride, or verapamil hydrochloride in intravenous admixtures.

The stability of amrinone and digoxin, procainamide hydrochloride, propranolol hydrochloride, sodium bicarbonate, potassium chloride, or verapamil hydrochloride in intravenous admixtures was studied. Admixtures of amrinone and digoxin were studied at one concentration. Amrinone admixtures with propranolol hydrochloride, sodium bicarbonate, potassium chloride, and verapamil hydrochloride were studied at two concentrations. In general, 0.45% sodium chloride injection was used as the diluent; 5% dextrose injection was also used for the procainamide hydrochloride experiments. Duplicate solutions of each test admixture and single-drug control admixture were prepared and stored for four hours at 22-23 degrees C under fluorescent light. Samples were analyzed by visual inspection, tested for pH, and assayed by high-performance liquid chromatography. Admixtures containing amrinone 1.25 or 2.5 mg/mL (as the lactate salt) and sodium bicarbonate 37.5 mg/mL precipitated immediately or within 10 minutes. No changes in pH or visual appearance were noted for amrinone admixtures with procainamide hydrochloride, digoxin, propranolol hydrochloride, potassium chloride, and verapamil hydrochloride. Appreciable degradation of both amrinone and procainamide was observed after four hours when the two were mixed in 5% dextrose. No degradation of amrinone or procainamide was seen when the 5% dextrose was replaced by 0.45% sodium chloride. Amrinone and sodium bicarbonate were incompatible in intravenous admixtures. Amrinone was compatible with digoxin, propranolol hydrochloride, potassium chloride, and verapamil hydrochloride. Amrinone and procainamide were compatible in 0.45% sodium chloride injection but not in 5% dextrose injection.     

Stability of fluorouracil, cytarabine, or doxorubicin hydrochloride in ethylene vinylacetate portable infusion-pump reservoirs.

The stability of fluorouracil, cytarabine, and doxorubicin hydrochloride in admixtures stored in portable infusion-pump reservoirs was investigated. Admixtures containing fluorouracil 50 or 10 mg/mL, cytarabine 25 or 1.25 mg/mL, or doxorubicin hydrochloride 1.25 or 0.5 mg/mL in 0.9% sodium chloride injection or 5% dextrose injection were placed in 80-mL ethylene vinylacetate drug reservoirs protected from light, and 1-mL quantities were withdrawn immediately after preparation and after storage for 1, 2, 3, 4, 7, 14, and 28 days at 4, 22, or 35 degrees C. For each condition, three samples from each admixture were tested for drug concentration by stability-indicating high-performance liquid chromatography. The admixtures were also monitored for precipitation, color change, and pH. Evaporative water loss from the containers was measured. Fluorouracil was stable at all temperatures for 28 days. Cytarabine was stable for 28 days at 4 and 22 degrees C and for 7 days at 35 degrees C. Doxorubicin hydrochloride was stable for 14 days at 4 and 22 degrees C and for 7 days at 35 degrees C. No color change or precipitation was observed, and pH values were stable. Loss of water through the reservoirs was substantial only at 35 degrees C for 28 days. When stored in ethylene vinylacetate portable infusion-pump reservoirs, fluorouracil, cytarabine, and doxorubicin hydrochloride were each stable for at least one week at temperatures up to 35 degrees C. Cytarabine and doxorubicin hydrochloride showed decreasing stability at longer storage times and higher temperatures.     

Stability of ranitidine admixtures frozen and refrigerated in minibags

The stability of ranitidine hydrochloride stored frozen and refrigerated in polyvinyl chloride minibags was studied. Ranitidine hydrochloride was added to either 5% dextrose injection or 0.9% sodium chloride injection to yield concentrations of 0.5, 1.0, and 2.0 mg/mL. In phase 1 of the study, admixtures containing ranitidine hydrochloride 1 mg/mL were stored at 4 degrees C for 10 days. In phase 2, solutions were frozen for 30 days at -30 degrees C and were later refrigerated for 14 days. Ranitidine concentration was tested using a stability-indicating high-performance liquid chromatographic assay at time zero and at intervals during storage. Sterility tests were performed on some samples, and various admixtures were visually inspected and tested for pH. At least 90% of the initial concentration of ranitidine remained in all solutions at all storage conditions. No visual changes or changes in pH or sterility were observed. Ranitidine hydrochloride in concentrations of 0.5, 1.0, and 2.0 mg/mL in 5% dextrose injection or 0.9% sodium chloride injection may be stored in polyvinyl chloride minibags frozen for 30 days followed by refrigeration for an additional 14 days.     

Stability of intravenous admixtures of aztreonam and ampicillin

The stability of aztreonam and ampicillin in intravenous admixtures containing both drugs was studied. Each of the following drugs and combinations of drugs was added to both 5% dextrose injection and 0.9% sodium chloride injection: aztreonam 10 and 20 mg/mL, ampicillin sodium 5 and 20 mg/mL, aztreonam 20 mg/mL and ampicillin sodium 20 mg/mL, aztreonam 20 mg/mL and ampicillin sodium 5 mg/mL, aztreonam 10 mg/mL and ampicillin sodium 20 mg/mL, and aztreonam 10 mg/mL and ampicillin sodium 5 mg/mL. One of each of these admixtures was stored at 25 degrees C for 48 hours and 4 degrees C for seven days. At various storage times the admixtures were inspected for visual changes and 2-mL samples were examined microscopically for crystalline and particulate matter, tested for pH, and assayed by high-performance liquid chromatography. No visual changes were observed. In the two-drug solutions, pH was influenced by concentrations of the two drugs and stability of the drugs was influenced by the solution pH. The pH of single-drug aztreonam admixtures did not change during storage, but the pH of single-drug and two-drug admixtures containing ampicillin decreased. In single-drug admixtures, aztreonam loss under both storage conditions was less than 10% but ampicillin loss was more than 10% in 0.9% sodium chloride injection and more than 50% in 5% dextrose injection. The stability of ampicillin was increased in the presence of aztreonam, and the stability of aztreonam was decreased in the presence of ampicillin.(ABSTRACT TRUNCATED AT 250 WORDS)     

Stability of amiodarone hydrochloride in admixtures with other injectable drugs

The stability of amiodarone hydrochloride in intravenous admixtures was studied. Amiodarone hydrochloride 900 mg was mixed with 500 mL of either 5% dextrose injection or 0.9% sodium chloride injection in polyvinyl chloride or polyolefin containers; identical solutions were also mixed with either potassium chloride 20 meq, lidocaine hydrochloride 2000 mg, quinidine gluconate 500 mg, procainamide hydrochloride 2000 mg, verapamil hydrochloride 25 mg, or furosemide 100 mg. All admixtures were prepared in triplicate and stored for 24 hours at 24 degrees C. Amiodarone concentrations were determined using a stability-indicating high-performance liquid chromatographic assay immediately after admixture and at intervals during storage. Each solution was visually inspected and tested for pH. Amiodarone concentrations decreased less than 10% in all admixtures except those containing quinidine gluconate in polyvinyl chloride containers. The only visual incompatibility observed was in admixtures containing quinidine gluconate and 5% dextrose injection. In most solutions pH either decreased slightly or remained unchanged. Amiodarone hydrochloride is stable when mixed with either 5% dextrose injection or 0.9% sodium chloride injection in polyvinyl chloride or polyolefin containers alone or with potassium chloride, lidocaine, procainamide, verapamil, or furosemide and stored for 24 hours at 24 degrees C. Amiodarone should not be mixed with quinidine gluconate in polyvinyl chloride containers.     

Stability of intravenous admixtures containing aztreonam and cefazolin

The stability of aztreonam and cefazolin in intravenous admixtures was studied. Each of the following combinations of drugs was added to both 5% dextrose injection and 0.9% sodium chloride injection in polyvinyl chloride containers: aztreonam 20 mg/mL and cefazolin 20 mg/mL (as the sodium salt); aztreonam 10 mg/mL and cefazolin 5 mg/mL; aztreonam 20 mg/mL and cefazolin 5 mg/mL; and aztreonam 10 mg/mL and cefazolin 20 mg/mL. One of each of these admixtures was stored at 23-25 degrees C for 48 hours and at 4-5 degrees C for seven days. At various storage times the admixtures were inspected for visual changes, and 1-mL samples were tested for pH and assayed using a stability-indicating high-performance liquid chromatographic assay. No visual changes were observed, and changes in pH were negligible. Concentrations of aztreonam and cefazolin under both storage conditions decreased by less than 3%. Intravenous admixtures of aztreonam and cefazolin at the concentrations studied are stable for at least 48 hours at 23-25 degrees C and for seven days at 4-5 degrees C.     

Stability of procainamide hydrochloride in neutralized 5% dextrose injection

The stability of procainamide hydrochloride in neutralized 5% dextrose injection was studied. Sixty-four admixtures were prepared by adding either 2 mL (for 0.4% admixtures) or 4 mL (for 0.8% admixtures) of procainamide hydrochloride to 250 mL of 5% dextrose injection in plastic containers. The pH of 32 of these admixtures (16 of each type) was adjusted to 7.5. These 32 admixtures represented the neutralized group, and the remaining 32 represented the control group. The admixtures were stored at either 23-25 degrees C (room temperature) or 5 degrees C (refrigeration) for 24 hours. Procainamide hydrochloride concentrations in each sample were determined by high-performance liquid chromatography immediately after the admixtures were prepared and at various intervals during storage. Procainamide concentrations decreased over time in 5% dextrose injection. The decrease was significantly less for admixtures in neutralized 5% dextrose injection, those stored under refrigeration, and those with an 0.8% concentration of drug. Decreases in procainamide hydrochloride concentrations in the control admixtures might have been caused by procainamide-dextrose complexation. Initial concentrations of procainamide hydrochloride in 5% dextrose injection can be adequately maintained over a 24-hour storage period by neutralizing the 5% dextrose injection or storing the admixture at 5 degrees C. However, because it is impractical to maintain the necessary temperature condition during a 24-hour infusion, neutralization might be the most viable alternative when extended stability of procainamide hydrochloride in 5% dextrose injection is required.     

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.     

Stability of intravenous admixtures of doxorubicin and vincristine

The stability of doxorubicin and vincristine in admixtures containing both drugs in 0.9% sodium chloride injection, 0.45% sodium chloride and Ringer's acetate injection, and 0.45% sodium chloride and 2.5% dextrose injection was studied. Doxorubicin hydrochloride was added to 30-mL quantities of each base solution to achieve initial doxorubicin concentrations of 1.40 mg/mL and to 0.9% sodium chloride injection to achieve concentrations of 1.88 and 2.37 mg/mL. Vincristine sulfate was added to each doxorubicin admixture to achieve vincristine concentrations of 0.033 and 0.053 mg/mL. All admixtures were protected from light and stored in polysiloxan bags that are used with portable delivery devices. Admixtures were kept at temperatures of 25, 30, and 37 degrees C. Samples withdrawn immediately after preparation and at 1, 2, 4, 7, 10, and 14 days were analyzed by high-performance liquid chromatography for content of each drug. The stability of doxorubicin was dependent on temperature and composition of the base solution. Analysis of data from the samples containing 0.45% sodium chloride and Ringer's acetate injection showed that doxorubicin concentrations were less than 90% of the initial concentration by 12 hours at 37 degrees C, 35 hours at 30 degrees C, and 62 hours at 25 degrees C, and visual changes occurred in all of these admixtures over the course of the study. Vincristine degradation also was most rapid in 0.45% sodium chloride and Ringer's acetate admixtures. Data analysis showed that concentrations of vincristine were less than 90% of initial after eight days at 25 degrees C, five days at 30 degrees C, and three days at 37 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)     

Stability of ganciclovir sodium (DHPG sodium) in 5% dextrose or 0.9% sodium chloride injections

The stability of 9-[(1,3-dihydroxy-2-propoxymethyl]) guanine sodium (ganciclovir sodium, also known as DHPG sodium) in two infusion solutions was studied. Lyophilized ganciclovir sodium 500 mg was reconstituted with sterile water 10 mL to give a theoretical concentration of 50 mg/mL. After reconstitution, 6-mL aliquots of the solution were added to 100 mL of 0.9% sodium chloride injection or 5% dextrose injection in polyvinyl chloride i.v. bags. One sample was withdrawn from each of 10 bags of each solution and analyzed by high-performance liquid chromatography (HPLC). Thirty bags of each solution were then stored under each of the following conditions: at room temperature under laboratory light, at room temperature in the dark, and under refrigeration for up to five days. Single potency assays were performed by HPLC on each of three bags of solution at three and five days after initial dilution of the solutions. The solutions were visually inspected, and the pH of the solutions was measured. All solutions of ganciclovir were stable for at least five days under all storage conditions; mean ganciclovir concentrations did not drop below 98% of initial theoretical values throughout the storage period. No important changes in the pH of the solutions occurred during the study period. Under the conditions of this study, ganciclovir sodium is stable for up to five days when prepared in 5% dextrose injection or 0.9% sodium chloride injection.     

Stability of levodopa in 5% dextrose injection at pH 5 or 6

The stability of solutions of levodopa 1 mg/mL in 5% dextrose injection adjusted to pH 5 or 6 and stored at one of three temperatures was determined. Solutions were adjusted to pH 5 or 6 with sodium acetate injection or sodium phosphate injection, respectively. Three samples of solution adjusted to pH 5 were stored at each of three temperatures (4, 25, and 45 degrees C), and three samples of solution adjusted to pH 6 were stored at 25 degrees C. Samples were assayed for levodopa concentration by high-performance liquid chromatography at various times during the 21-day study period. All solutions maintained at least 90% of the initial concentration of levodopa for seven days. Discoloration of all solutions except those stored at 4 degrees C was noted at some point during the study period; solutions stored at 45 degrees C began to darken within 12 hours. The pH values of the solutions did not change during the study period. Under the conditions studied, solutions of levodopa 1 mg/mL in 5% dextrose injection adjusted to pH 5 or 6 are stable for seven days. Slight degradation of levodopa may cause a brownish-black discoloration of the admixtures.     

Stability of intravenous admixtures of aztreonam and clindamycin phosphate

The stability of aztreonam and clindamycin phosphate in intravenous admixtures was studied. Each of the following combinations of drugs was added to both 5% dextrose injection and 0.9% sodium chloride injection: aztreonam 20 mg/mL and clindamycin phosphate 6 mg/mL; aztreonam 20 mg/mL and clindamycin phosphate 3 mg/mL; aztreonam 10 mg/mL and clindamycin phosphate 6 mg/mL; and aztreonam 10 mg/mL and clindamycin phosphate 3 mg/mL. One of each of these admixtures was stored at 22-23 degrees C for 48 hours and at 4 degrees C for seven days. At various storage times the admixtures were inspected for visual changes and 1-mL samples were examined microscopically for crystalline and particulate matter, tested for pH, and assayed using high-performance liquid chromatography. No visual changes were observed. The pH of admixtures decreased only slightly during storage. Concentrations of aztreonam and clindamycin phosphate under both storage conditions decreased by less than 10%. Intravenous admixtures of aztreonam and clindamycin phosphate at the concentrations studied are stable for at least 48 hours at 22-23 degrees C and at least seven days at 4 degrees C.