Key Influencing Factors of Stability of 1, 4-Dihydropyridine Drug Solutions / 中国药学杂志

ABSTRACT

OBJECTIVE: To study the stability of 1, 4-dihydropyridines solutions and the key influencing factors. METHODS: The stabilities of the solutions of several representative drugs, ie, benidipine hydrochloride, amlodipine besylate and nifedipine, were tested in six kinds of solvents of different pHs (pH 1.0, pH 1.2, pH 2.0 hydrochloric acid solutions, pH 4.0 acetic acid solution, pH 6.8 phosphoric acid solution, water) by HPLC method. The effects of several metal ions, Fe3+ concentration and different pH values on the stability of the drug solutions were also investigated. RESULTS: Fe3+could lead to rapid degradation of 1, 4-dihydropyridine drugs, the degradation rate was accelerated with the increase of Fe3+concentration, and the degradation rate was decreased with the increase of pH value. CONCLUSION: The aromatization of 1, 4-dihydropyridines by Fe3+is the main reason for the degradation of 1, 4-dihydropyridines.