Migration and Safety Evaluation of Bromide in Bromobutyl Rubber Stopper for Freeze-Dried Powder Injection

The extraction method of bromide in bromobutyl rubber stopper has been established, and the leaching level of bromide in freeze-dried powder was investigated. A chromatographic column IonPac AS 11-H (4.0 mm×250 mm) and a guard column IonPac AS 11-HC (4.0 mm×50 mm), and a 24 mmol/L potassium hydroxide solution were used for the isocratic elution. Bromide was detected by suppressed conductivity with an AERS 500(4 mm) suppressor at a current of 60 mA. The column temperature was 30 ℃ and the flow rate was 1.0 mL/min. The calibration curve showed a good linearity (r＝0.999 9) in the range of 0.2~10.0 mg/L and the limit detection (LOD) was 0.007 mg/L. The brominated butyl rubber stopper was extracted by 30% isopropanol aqueous solution at 80 ℃ for 7 hours. The freeze-dried powder was redissolved in ultrapure water to detect the amount of bromide migration directivity. The average recoveries of the migration test were between 98.1% and 104.3%, and the relative standard deviations (RSD, n=6) were from 2.9% to 4.3%. The method can be used for the detection of real samples in the compatibility test of packaging materials.