Atta-Politou J, Skopelitis I, Apatsidis I, Koupparis M
Laboratory of Analytical Chemistry, Department of Chemistry, University of Athens, Panepistimiopolis, 15771, Athens, Greece.
Eur J Pharm Sci. 2001 Jan;12(3):311-9. doi: 10.1016/s0928-0987(00)00187-1.
This in vitro investigation was performed to study the adsorption rate constant as well as the adsorption characteristics of fluoxetine (F) to activated charcoal and its commercial formulation Carbomix powder in simulated gastric (pH 1.2) fluid environment. Ion-selective electrode (ISE) potentiometry, based on the selective, direct and continuous monitoring of F with an F-ISE constructed in our laboratory was used. The method used in the kinetic experiments consists of the rapid addition of a slurry containing the charcoal into the drug solution under stirring and continuous recording of the F-ISE potential until the establishment of equilibrium. The free ionized drug concentration at appropriate time intervals was calculated from the recorded adsorption curve and the apparent adsorption rate constant was estimated assuming pseudo first order kinetics. Within run R.S.D. of the estimates ranged from 0.24 to 11.5%, while between run R.S.D. (n=3-4) ranged from 0.90 to 13.8%. A linear relationship was found between the apparent adsorption rate constants and the amount of charcoal used with slopes (+/-S.D.) for activated charcoal and Carbomix equal to 1.14(+/-0.21) and 0.146(+/-0.009) s(-1)g(-1), respectively. Successive additions of microvolumes of F solution were made into a charcoal slurry with measurement of the F-ISE potential at equilibrium. The maximum adsorption capacity values (+/-S.D.) of activated charcoal and Carbomix were 254.8+/-1.8 and 405+/-41 mg/g, respectively while the affinity constant values (+/-S.D.) were 45.6+/-2.2 and 55.5+/-2.9 l/g, respectively. The adsorption of F to charcoals was rapid and for amounts of charcoal 10 times greater than the amount of the drug, 95% of F was adsorbed within the first 5 min. Relative to the toxic and lethal doses in cases of F intoxications, both types of charcoals tested adsorbed effectively F at gastric pH. Carbomix can be considered as appropriate charcoal formulation for medical treatment in cases of F poisoning.
进行这项体外研究是为了研究氟西汀（F）在模拟胃液（pH 1.2）环境中对活性炭及其商业制剂Carbomix粉末的吸附速率常数和吸附特性。采用离子选择性电极（ISE）电位分析法，基于在我们实验室构建的F-ISE对F进行选择性、直接和连续监测。动力学实验中使用的方法包括在搅拌下将含有活性炭的浆液快速加入药物溶液中，并持续记录F-ISE电位直至达到平衡。根据记录的吸附曲线计算适当时间间隔下的游离离子化药物浓度，并假设伪一级动力学估算表观吸附速率常数。单次运行中估算值的相对标准偏差（R.S.D.）范围为0.24%至11.5%，而多次运行间的R.S.D.（n = 3 - 4）范围为0.90%至13.8%。发现表观吸附速率常数与所用活性炭量之间存在线性关系，活性炭和Carbomix的斜率（±标准偏差）分别等于1.14（±0.21）和0.146（±0.009）s⁻¹g⁻¹。将微量F溶液逐次加入活性炭浆液中，并在平衡时测量F-ISE电位。活性炭和Carbomix的最大吸附容量值（±标准偏差）分别为254.8 ± 1.8和405 ± 41 mg/g，而亲和常数（±标准偏差）分别为45.6 ± 2.2和55.5 ± 2.9 l/g。F对活性炭的吸附迅速，当活性炭用量比药物量高10倍时，95%的F在最初5分钟内被吸附。相对于F中毒情况下的中毒剂量和致死剂量，两种测试的活性炭在胃pH值下都能有效吸附F。Carbomix可被视为F中毒病例医疗治疗的合适活性炭制剂。
