The stability of propafenone hydrochloride in i.v. solutions was studied. Solutions of propafenone hydrochloride 2, 1, and 0.5 mg/mL in 5% dextrose injection and in 5% dextrose and 0.2% sodium chloride injection were prepared. Portions of each type of solution were transferred to 10-mL polypropylene syringes and to 150-mL polyvinyl chloride (PVC) bags. Syringes and bags were stored at 20.5-22.5 degrees C under fluorescent light. Two 0.5-mL samples were drawn from each container at 0, 6, 12, 24, 36, and 48 hours and frozen in polystyrene tubes at -20 degrees C until assayed. Propafenone concentrations were determined by high-performance liquid chromatography. All samples of propafenone hydrochloride 2 mg/mL in 5% dextrose and 0.2% sodium chloride injection taken from PVC bags precipitated when thawed. For the remaining solutions, the mean decrease from the initial concentration was < 10% regardless of diluent, container type, and initial concentration. Propafenone hydrochloride 1 and 0.5 mg/mL in 5% dextrose injection or in 5% dextrose and 0.2% sodium chloride injection was stable for 48 hours at 20.5-22.5 degrees C when stored in polypropylene syringes or PVC bags. Propafenone hydrochloride 2 mg/mL in 5% dextrose injection was stable for 48 hours when stored in syringes or bags, but in 5% dextrose and 0.2% sodium chloride injection was stable in syringes only.