Compatibility and stability of clindamycin phosphate-aminoglycoside combinations within polypropylene syringes.
The stability and compatibility of clindamycin phosphate admixed separately with gentamicin sulfate, tobramycin sulfate, and amikacin sulfate in polypropylene syringes under specific storage conditions were studied. In duplicate syringes, clindamycin phosphate 900 mg was admixed with sterile NaCl 0.9% l ml and with either gentamicin sulfate 120 mg, tobramycin sulfate 120 mg, or amikacin sulfate 750 mg. In duplicate polypropylene syringes, control solutions of clindamycin phosphate and each aminoglycoside were prepared separately and stored under the same conditions. The clindamycin control consisted of clindamycin phosphate 900 mg in 6 ml. The gentamicin and tobramycin controls consisted of gentamicin sulfate and tobramycin sulfate 120 mg in 3 ml plus 1 ml of sterile NaCl 0.9%. The amikacin control consisted of amikacin sulfate 750 mg in 3 ml plus 1 ml of sterile NaCl 0.9%. Drug concentrations were determined at the time of preparation and 1, 4, 8, 12, 24, and 48 hours thereafter. Aminoglycosides were assayed by fluorescence polarization immunoassay and clindamycin was assayed by high performance liquid chromatography. Visual inspections and pH determinations of each combination and control solution were performed at each assay time. For the clindamycin, gentamicin, tobramycin, and amikacin control solutions, changes in concentration were within ten percent of the original concentration. Concentrations of clindamycin and gentamicin when admixed together also remained within ten percent of the original concentration. Similar results were found with concentrations of clindamycin and amikacin when admixed together. Tobramycin and clindamycin formed a lasting precipitate upon initial contact when admixed under the study conditions.
Department of Pharmacy Practice, College of Pharmacy, University of Utah, Salt Lake City 84112.
A S
AS
Zbrozek
D A
DA
Marble
J A
JA
Bosso
J N
JN
Bair
R J
RJ
Townsend
D000583:Amikacin / Q000032:analysis; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000032:analysis*; D002981:Clindamycin / Q000008:administration & dosage / Q000032:analysis*; D004338:Drug Combinations; D004344:Drug Incompatibility; D004355:Drug Stability; D005839:Gentamicins / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D011126:Polypropylenes; D013594:Syringes; D014031:Tobramycin / Q000032:analysis
D000900:Anti-Bacterial Agents; D004338:Drug Combinations; D005839:Gentamicins; D011126:Polypropylenes; D002981:Clindamycin; D000583:Amikacin; D014031:Tobramycin