Compatibility of clindamycin phosphate with cefotaxime sodium or netilmicin sulfate in small-volume admixtures

The stability and compatibility of clindamycin phosphate plus either cefotaxime sodium or netilmicin sulfate in small-volume intravenous admixtures were studied. Admixtures containing each drug alone and two-drug admixtures of clindamycin phosphate plus cefotaxime sodium or netilmicin sulfate were prepared in 100 mL of 5% dextrose injection and 0.9% sodium chloride injection in both glass bottles and polyvinyl chloride (PVC) bags. Final concentrations of clindamycin, cefotaxime, and netilmicin were 9, 20, and 3 mg/mL, respectively. All solutions were prepared in duplicate and stored at room temperature (24 +/- 2 degrees C). Samples were visually inspected, tested for pH, and assayed for antibiotic concentration using stability-indicating assays at 0, 1, 4, 8, 16, and 24 hours for admixtures in glass bottles and at 0, 8, and 24 hours for admixtures in PVC bags. No substantial changes in color, clarity, pH, or drug concentration were observed in any of the solutions. Clindamycin phosphate is compatible with cefotaxime sodium or netilmicin sulfate in 5% dextrose and 0.9% sodium chloride injections in glass bottles or PVC bags for 24 hours.