Physico-Chemical Stability of Sodium Thiosulfate Infusion Solutions in Polyolefin Bags at Room Temperature over a Period of 24 Hours

Abstract Background Many publications described sodium thiosulfate used to prevent the renal toxicity induced by cisplatin hyperthermic intraperitoneal chemotherapy. After around 60 or 90 minutes of hyperthermic chemotherapy, cisplatin was drained and then, sodium thiosulfate was infused by intravenous route. Sodium thiosulfate is used in two steps: a first step, at 9 g/m2 in 250 mL of 0.9 % sodium chloride over 10 minutes followed by a second step, at 12 g/m2 in 1000 mL of 0.9 % sodium chloride over 6 hours. The purpose of this work was to study the stability of sodium thiosulfate at 16 mg/mL in 0.9 % sodium chloride polyolefin bags 1000 mL and at 72 mg/mL in 0.9 % sodium chloride polyolefin bags 250 mL, at 25 °C, protected or unprotected from light. Methods Chemical stability was analysed by high performance liquid chromatography (HPLC) coupled to a photodiode array detector after preparation and after 6-hour or 24-hour storage. The method was validated according to the International Conference on Harmonisation (ICH). Physical stability was evaluated by visual and subvisual inspection (turbidimetry by UV spectrophotometry at 550 nm). Three bags for each condition were prepared. On each time of the analysis, three samples were prepared for each bag and analysed by HPLC. pH values were evaluated on each moment of the analysis. Results Sodium thiosulfate solutions diluted in 0.9 % sodium chloride at 16 and 72 mg/mL retained more than 95 % of the initial concentration during 24 hours. Concerning pH measurements, the maximum variation was 0.24 pH unit. No visual modification such as colour change, precipitation or gas formation was observed. The absorbance at 550 nm obtained for each sample was less than 0.010 AU. Conclusions Sodium thiosulfate solutions at 16 mg/mL in 1000 mL 0.9 % sodium chloride and at 72 mg/mL in 250 mL 0.9 % sodium chloride are stable physically and chemically over a period of 24 hours at 25 °C, with or without protection from light. This stability study allows the use of sodium thiosulfate in renal protection protocols during cisplatin hyperthermic intraperitoneal chemotherapy.