Moxalactam disodium compatibility with intramuscular and intravenous diluents.

The stability of moxalactam disodium with mannitol injection in combination with intramuscular and intravenous diluents was investigated. Solutions were stored in original glass containers stoppered with butyl rubber closures or in polyvinyl chloride bags. Five diluents were evaluated at an intramuscular concentration of moxalactam 1 g (as the disodium salt) in 3 ml of diluent. Twenty intravenous diluents were evaluated with moxalactam 1 g (as the disodium salt) in 50 or 500 ml of diluent. High-performance liquid chromatography, polarography, thin-layer chromatography, spectrophotometric color evaluations, nephelometry, and pH determinations were performed. Solutions were assayed initially after reconstitution and stored for subsequent assay at refrigerator (5 degrees C) and room (25 degrees C) temperatures. The moxalactam disodium solutions were stable for up to 96 hours when stored at 5 degrees C or 24 hours when stored at 25 degrees C. The color, clarity, and TLC data were satisfactory for all diluent combinations tested. Polarographic, HPLC, and TLC data showed that the degradation products remained within acceptable limits when stored for 96 hours at 5 degrees C or 24 hours at 25 degrees C. The slight pH changes were within regulatory limits for moxalactam. The moxalactam disodium solutions maintained at least 90% of initial potency for up to 96 hours when stored in a refrigerator. If kept at room temperature, the reconstituted solutions should be used within 24 hours.

Stability of frozen solutions of cefazolin sodium.

The stability of frozen solutions of cefazolin sodium was investigated in nine commonly used diluents at concentrations of 1 g with 2.5 ml, 500 mg with 100 ml and 10 g with 45 ml in both glass and polyvinylchloride plastic containers. The diluents were: Water for Injection USP; 0.9% Sodium Chloride Injection USP; 5% Dextrose Injection USP (D5W); D5W with 0.02% sodium bicarbonate; D5W in Lactated Ringer's Injection USP; Lactated Ringer's Injection USP; Ionosol B in D5W; Normasol M in D5W; and Plasmalyte in D5W. Frozen cefazolin sodium solutions, containing Water for Injection USP, 5% Dextrose Inection USP or 0.9% Sodium Chloride Injection USP as the diluents, retained more than 90% of labeled potency for up to 26 weeks when frozen within one hour after reconstitution and held at -10 C or -20 C. Frozen cefazolin sodium solutions, made with other diluents, were stable for up to four weeks when frozen within one hour after reconstitution and held at -10 C.