Bacteria from the exit site of dialysis
catheter can grow into microcolonies in biofilm. It has been hypothesized that
rifampin-
protamine combination may have an effect on the biofilm. In
hemodialysis centre a combination of
rifampin mixed with
protamine is commonly used in some centre in order to prevent
catheter related infections in
hemodialysis patients. Therefore, a
pharmaceutical assessment of the
rifampin-
protamine mixture is clearly mandatory. The aim of this study is to evaluate the stability and the
sterility of the
rifampin-
protamine solution. Five milliliters of
protamine (10 mg) was mixed with 10 mL of
Rifampin (600 mg). The
solution was kept at -20 degrees C temperature for two weeks and subsequently at 4 degrees C for two additional weeks. Stability and
sterility were evaluated the first day and two weeks, three weeks and four weeks after the preparation. Concentration of
rifampin in the
solution was assessed by HPLC.
Protamine concentration was evaluated by the effect of the
solution on the
heparin activity of a heparinized plasma. The
solution was cultured on broth media and
mannitol agar plate. Areas under curve of
rifampin were similar between the four different evaluations. The effect of the
solution on the
heparin activity was comparable at the four different evaluations. Our results demonstrate the stability and the compatibility of the
solution. However, there was
biological interference between broth media and the
solution. It was, therefore, impossible to make any conclusion after broth culture. Culture on
mannitol agar plate did not show any microbiological growth. Based on this finding, we recommend preparing the
rifampin-
protamine combination in individual conditioning at the time of the utilization.