INFLUENCE OF PHYSICOCHEMICAL PROPERTIES OF FLUOROQUINOLONES ON ENCAPSULATION EFFICIENCY IN LIPOSOMES

Three fluoroquinolones, ciprofloxacin, norfloxacin and a newly synthes ized compound (CNV-8912), were encapsulated in liposomes of DPPC at pH 7.40 and encapsulation efficiency was determined by two methods: spec trophotometry of isopropanol-lysed vesicles and HPLC. These methods ar e compared with a view to the reproducibility and sensitivity of each technique. Physicochemical properties such as octanol-buffer coefficie nts and pKs were determined in order to interpret the encapsulation ef ficiency values in terms of affinity for lipid environments and micros peciation at pH 7.40.