Mendes Cassiana, Buttchevitz Aline, Barison Andersson, Ocampos Fernanda Maria Marins, Bernardi Larissa Sakis, Oliveira Paulo Renato, Silva Marcos Antônio Segatto
Post graduation Program in Pharmaceutical Sciences, Quality Control Laboratory, Federal University of Santa Catarina (UFSC), Florianópolis, SC, Brazil.
Expert Rev Anti Infect Ther. 2015 Jan;13(1):131-40. doi: 10.1586/14787210.2015.982092.
Norfloxacin (NFX) is a broad spectrum antibiotic with low solubility and permeability, which is unstable on exposure to light and humidity.
In this study, the mode of NFX inclusion into β-cyclodextrin complexes was evaluated and a complete physical, chemical and microbiological stability study of the inclusion complexes was carried out.
Potentiometric titrations were performed to evaluate changes in the pKa of the NFX molecule due to the formation of an inclusion complex and NMR analysis demonstrated that the NFX molecule is included in the β-cyclodextrin cavity.
Inclusion complexes obtained by kneading followed by freeze-drying showed improved NFX stability compared with the isolated drug or the physical mixture. This method was effective in terms of protecting the drug from photodegradation and also avoiding hydrolysis. Differences between NFX and the complexes could be evidenced by thermal analysis, infrared spectroscopy and x-ray powder diffraction as well as by determining the solubility and drug content. The antimicrobial potency was also preserved on applying the promising method of kneading.
The satisfactory stability indicates that the NFX/β-cyclodextrin complexes could be useful as an alternative to the existing NFX drug formulation.
诺氟沙星（NFX）是一种溶解度和渗透性较低的广谱抗生素，在光照和湿度条件下不稳定。
在本研究中，评估了NFX包合进入β-环糊精复合物的方式，并对包合复合物进行了全面的物理、化学和微生物稳定性研究。
进行电位滴定以评估由于包合复合物形成导致的NFX分子pKa变化，核磁共振分析表明NFX分子被包合在β-环糊精腔内。
通过捏合后冷冻干燥获得的包合复合物与游离药物或物理混合物相比，显示出更好的NFX稳定性。该方法在保护药物免受光降解以及避免水解方面有效。通过热分析、红外光谱、X射线粉末衍射以及测定溶解度和药物含量，可以证明NFX与复合物之间的差异。应用有前景的捏合方法时，抗菌效力也得以保留。
令人满意的稳定性表明，NFX/β-环糊精复合物可作为现有NFX药物制剂的替代品。
