Determination of free and liposome-associated doxorubicin and vincristine levels in plasma under equilibrium conditions employing ultrafiltration techniques
Determination of free and liposome-associated doxorubicin and vincristine levels in plasma under equilibrium conditions employing ultrafiltration techniques
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DOI：
10.1006/abio.1995.0001
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发表时间：
1995-12-10
影响因子：
2.9
通讯作者：
StOnge, G
中科院分区：
文献类型：
--
作者：
Mayer, LD;StOnge, G
彻底了解脂质体包裹的抗癌药物(如阿霉素和长春新碱)的毒性和疗效行为的药效学关系，将取决于准确分离和定量给药后血浆中游离和脂质体相关药物组分的能力。我们研究了超滤在平衡条件下从脂质体药物中分离游离阿霉素和长春新碱的方法，并与以前开发的基于固相萃取的非平衡方法进行了比较。将溶解于生理盐水的药物吸附到超滤装置上，可得到浓度依赖的超滤液药物回收率为41%~96%。然而，用聚乙二醇8000钝化超滤装置，可以实现对盐溶液中长春新碱的非浓度依赖的定量回收，并改善了两种药剂的装置药物吸附。超滤法提供了更可靠的分离游离药物和蛋白质结合药物的方法，而固相萃取法由于过程诱导的蛋白质结合药物复合体的解离而人为地产生了较高的游离药物浓度。此外，使用固相萃取技术测定脂质体中游离阿霉素和长春新碱的含量，与固相萃取相比，游离药物组分的洗脱率是超滤法的-到418倍，这些特性表明，与固相萃取法相比，使用超滤法测定含有脂质体配方的样品中游离阿霉素和长春新碱的准确度显著提高。这一改进的重要性通过观察到，注射了脂质体阿霉素和长春新碱的小鼠血浆中游离药物浓度的测定使用固相萃取比超滤高3到12倍。最后，超滤过程快速、通用，可用于大范围的药物和脂质体浓度和游离药物/脂质体药物比例的测定。(C)1995年学术出版社。
A thorough understanding of the pharmacodynamic relationships associated with toxicity and efficacy behavior of liposome-encapsulated anticancer agents such as doxorubicin and vincristine will rely on the ability to accurately separate and quantify the free and liposome-associated drug fractions in plasma after administration. We have investigated the use of ultrafiltration as a method of isolating free doxorubicin and vincristine from liposomal drug under equilibrium conditions and compared it to previously developed nonequilibrium procedures based on solid-phase extraction. Adsorption of drugs dissolved in saline to the ultrafiltration devices resulted in concentration-dependent ultrafiltrate drug recoveries ranging from 41 to 96%. However, concentration-independent quantitative recovery of vincristine in saline solutions could be obtained by passivating the ultrafiltration devices with PEG-8000 and device drug adsorption was ameliorated for both agents by plasma. The ultrafiltration method provided a more reliable separation of free and protein-bound drug, whereas solid-phase extraction yielded artificially high free drug concentrations due to process-induced protein-bound drug complex dissocation. Also, coelution of liposomes with the free drug fraction using solid-phase extraction was 64- to 418-fold higher than observed with ultrafiltration, Taken together, these properties indicated a significantly increased degree of accuracy in measuring the amount of free doxorubicin and vincristine in samples containing liposomal formulations employing ultrafiltration compared to solid-phase extraction. The importance of this improvement was highlighted by observations that determinations of free drug concentrations in the plasma of mice injected with liposomal doxorubicin and vincristine were 3- to 12-fold higher using solid-phase extraction compared to ultrafiltration. Finally, the ultrafiltra- tion procedure is rapid, versatile, and can be used for a wide range of drug and liposome concentrations and free drug/liposomal drug ratios. (C) 1995 Academic Press, Inc.