Quinidine gluconate, quinidine polygalacturonate, and quinidine sulfate darken on exposure to light and should be stored in well-closed, light resistant containers. Solutions of quinidine salts slowly acquire a brownish tint on exposure to light. Only colorless, clear solutions of quinidine gluconate injection should be used. Quinidine gluconate injection should be stored at 15-30 °C. When diluted to a concentration of 16 mg/ml with 5% dextrose injection, quinidine gluconate injection is stable for 24 hours at room temperature and up to 48 hours when refrigerated. /Quinidine salts/