[Efficacy testing of stabilizing agents in epinephrine model solutions. 19: Stability of drugs and preparations]

The efficiency of 54 stabilizers was tested on epinephrine solutions using a selection-combination method. The addition of only one antioxidant produces but slight improvements in stability. Maximal additive activity is achieved by the combination of two antioxidants. Superadditive effects (which are necessary for considerable prolongation of the time of applicability of aqueous epinephrine solutions) are obtained by the combination of antioxidants of different modes of action and a discolouration-protective agent or a synergist. On this basis, the authors developed an efficient stabilizing procedure for pharmaceutical preparations containing active principles sensitive to oxidation. The relationship between the concentration of the stabilizer and the stabilizing effect is demonstrated by examples.