[Stability testing of amphotericin B nasal spray solutions with chemical and biological analysis]

Recent studies have shown that the presence of fungal cells in the nasal mucosa may play an important role in the development of chronic rhinosinusitis with nasal polyps. In 2006 a pilot clinical trial was organized by the Department of Otorhinolaryngology, Head and Neck Surgery and the Pharmaceutical Institute of the Medical University of Pécs for the treatment of patients with chronic rhinosinusitis with nasal polyps. In our study we investigated the stability of the 5 mg/ml amphotericin B solutions (Fungizone) with chemical (spectrophotometry) and biological (bioassay) detection. The effect of storage temperature and the addition of 5% glucose was evaluated on the stability of the solutions for three months. The two detection methods showed different results. According to the chemical analysis the samples are considered relatively stable under all observed conditions (loss of concentration is: 14.2% at 20 degrees C and 4.5% at 4 degrees C). The bioassay shows complete loss of antifungal activity after 35 days of storage at room temperature and notable decrease can be observed at 4 degrees C (glucose containing solution 17.6%; glucose free solution 37.2%). Storage temperature had significant effect (p < 0.05), while 5% glucose had no significant effect (p > 0.05) on the stability of the examined solutions. Bioassay is considered to be the official quantitative analytical method for the analysis of amphotericin B recommended by the European Pharmacopoeia 4. Thus we estimated the shelf life of the glucose-free solutions, being stored at 4 degrees C, to be 30 days in accordance with our bioassay results.