Stability of quinine dihydrochloride in commonly used intravenous solutions

The stability of quinine dihydrochloride (Q) at a concentration of 12 mg/ml, in three common intravenous (i.v.) solutions, was studied. Admixtures of Q were prepared in the following vehicles, in glass containers: 5% dextrose in water, 5% dextrose in normal saline solution and normal saline solution. The solutions were kept under fluorescent light at room temperature. Concentrations of Q were monitored for 24 h using a stability–indicating high–pressure liquid chromatographic (HPLC) method. More than 90% of the initial concentration of Q remained in all solutions under the study conditions, and all samples remained clear and colourless over the entire 24–h period. Admixtures containing Q at a concentration of 1.2 mg/ml in the three solutions were stable (<10% decomposition) for at least 24 h and did not require protection from light. However, the use of the admixtures as soon as possible after preparation is still recommended because some decrease in concentration was observed on storage.