STUDY OF THE EFFECT OF B-CYCLODEXTRIN ON THE STABILITY OF NORFLOXACIN C

CLAUDIA GARNERO; ANA KARINA CHATTAH; LUIS FABIETTI; MARCELA LONGHI

Córdoba

Congreso; 3° Reunión Internacional de Ciencias Farmacéuticas - RICIFA2014 -; 2014

The polymorphism, the ability of a single compound to exist in multiple crystalline solid forms, may affect the chemical and physical properties of an active pharmaceutical ingredient (API), with a critical impact on its pharmaceutical profile. The formation of complexes with cyclodextrins (CDs) is a strategy developed to improve physicochemical properties of API. Norfloxacin (NOR), a synthetic broad antibacterial fluoroquinolone that exists in several solid forms, was select as API model and the chosen form for this study was its NOR form C. Previously, supramolecular systems of NOR C and -cyclodextrin (-CD) were developed, so in this study, the effect of these systems on chemical and physical stability of NOR C in solid state was investigated. The stability of NOR C, the NOR C:-CD system, obtained by kneading method, and their physical mixture were evaluated under accelerated storage conditions (at 40°C and 75% relative humidity). The solid samples were stored in closed glass vials exposed to daylight over a 6 month period into a stability chamber. The samples, at predetermined intervals, were monitored. The chemical stability was determined by high performance liquid chromatography (HPLC), while solid state nuclear magnetic resonance (ssNMR) and powder X-ray diffraction (PXRD) were used to evaluate the physical stability and possible phase transformations. Moreover, the hygroscopicity was determined. Our results revealed that NOR C and the physical mixture suffered the chemical degradation process. While, the amount of NOR C remains constant in the NOR C:-CD system, indicating that the interaction between -CD and NOR C increase the stability of the polymorph. Furthermore, it was observed absence of polymorphic transformations indicating that the samples maintained their physical stability. In conclusion, the NOR C:-CD system constitute an alternative tool to improve the physicochemical properties of this polymorph, with potential application in the preparation of pharmaceutical dosage products.