Colino C I, García Turiño A, Sanchez Navarro A, Lanao J M
Department of Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, Salamanca, Spain.
Biopharm Drug Dispos. 1998 Mar;19(2):71-7. doi: 10.1002/(sici)1099-081x(199803)19:2<71::aid-bdd72>3.0.co;2-g.
The present work deals with the in vitro and in vivo distribution of ofloxacin and ciprofloxacin in erythrocytes. In vitro studies were carried out in standard solutions prepared using fresh blood for a concentration range between 100 and 0.25 micrograms mL-1. A 5 mg kg-1 bolus dose was administered to rabbits and erythrocyte and plasma kinetics were determined over 8 h. A linear model was used to establish the relationship between plasma and erythrocyte concentrations of both quinolones in vitro. The mean partition coefficient values obtained were 1.04 +/- 0.02 and 1.32 +/- 0.03 for ofloxacin and ciprofloxacin, respectively. A decrease in the ciprofloxacin partition coefficient was observed at higher concentrations. Values ranged between 2.54 +/- 0.40 and 1.38 +/- 0.15 as the concentrations increased. The partition coefficients obtained from the linear relationship between plasma and erythrocyte concentrations established from the in vivo data were 0.80 +/- 0.58 for ofloxacin and 0.61 +/- 0.30 for ciprofloxacin. In vivo plasma and erythrocyte data analysis was performed by a deconvolution method and the theoretical transfer curves in erythrocytes were estimated. The distribution of both quinolones to erythrocytes is very rapid, probably due to a high permeability of erythrocyte membranes to these drugs. This was also confirmed by the parallelism between plasma and erythrocyte kinetics.
本研究涉及氧氟沙星和环丙沙星在红细胞中的体外和体内分布。体外研究是在使用新鲜血液制备的标准溶液中进行的，浓度范围为100至0.25微克/毫升。给兔子静脉注射5毫克/千克的大剂量药物，并在8小时内测定红细胞和血浆动力学。使用线性模型建立体外两种喹诺酮类药物血浆浓度与红细胞浓度之间的关系。氧氟沙星和环丙沙星获得的平均分配系数值分别为1.04±0.02和1.32±0.03。在较高浓度下观察到环丙沙星分配系数降低。随着浓度增加，值在2.54±0.40和1.38±0.15之间变化。根据体内数据建立的血浆浓度与红细胞浓度之间的线性关系获得的分配系数，氧氟沙星为0.80±0.58，环丙沙星为0.61±0.30。通过去卷积方法对体内血浆和红细胞数据分析，并估计红细胞中的理论转运曲线。两种喹诺酮类药物向红细胞的分布非常迅速，这可能是由于红细胞膜对这些药物具有高渗透性。血浆和红细胞动力学之间的平行性也证实了这一点。
