Abstract
We examined the changes in potency of polymyxin B sulfate (PL-B) solution on the following two factors, the concentrations of PL-B solution and sterilization methods of PL-B solution. The treatment with a filter (0.22μm) lowered the potency to 97-98% at concentrations of 1, 000, 3, 000 and 5, 000 units/mL of PL-B solutions immediately after filtration and the potency remained unchanged until 3 months. Treatments using an autoclave markedly lowered the potency to 70.0%, 76.6% and 84.0% at concentrations of 1, 000, 3, 000 and 5, 000 units/mL of PL-B solutions immediately after autoclaving at 115°C and 0.7 kg/cm2 for 30 min, respectively. No subsequent decreases in the PL-B potency with sterilization by autoclaving were observed during the 3-month period.
