Browsing by Subject "macrolide"

The characteristics of macrolides are discussed in general level in the theoretical part of this Master's thesis. The discussion is focused on the properties of two macrolides in molecular level and their tendency to form tautomeric forms highlighting the structural similarities and differences of these macrolides, which will affect both the mechanisms of action and the metabolism. Attention is also paid to biosynthesis and manufacturing process keeping focus on downstream process, especially the impurities, which arise from the macrolide biosynthesis. Also the principles of argentation chromatography are discussed. In the experimental part of Master's thesis a purification method for one macrolide was developed using argentation chromatography. Conventional chromatographic purifications cannot separate the macrolide from its impurities. The purity of the macrolide after argentation chromatography was 98.6%. Also a new crystallization method was developed, which produces anhydrous form of the macrolide instead of traditional monohydrate form. A method for analysing the macrolide using HPLC was developed. The method was validated according to ICH guidelines. The tautomeric forms and the impurities of the macrolide were analysed using LC/MS. One of these impurities was isolated and analysed with NMR thus confirming its identity. An analysed NMR spectrum of this impurity has not been published according to our best knowledge. A previously unknown impurity was identified based on MS analysis and retention time.