Departamento de Fármacos e Medicamentos, UNESP, Araraquara, SP, Brazil.
Colloids Surf B Biointerfaces. 2010 May 1;77(1):47-53. doi: 10.1016/j.colsurfb.2010.01.004. Epub 2010 Jan 14.
Structure and viscoelastic properties of negatively charged oil-in-water (o/w) microemulsions have been investigated. Microemulsions (ME) containing soya phosphatidylcholine (SPC), eumulgin HRE 40 (EU) and sodium oleate (SO) as surfactant, cholesterol (CHO) as oil phase, and aqueous buffer with and without the antitumoral doxorubicin (DOX) have been studied. The effect of the oil phase/surfactant ratio (O/S) and the DOX incorporation on the structural and rheological properties have been studied in several compositions of ME systems. The rheological analyses were performed through the oscillation stress sweep, creep recovery test, and viscosity test. The combination of the DOX incorporation with the high O/S ratio provided a further viscoelastic structure with linear behavior. Independently of the O/S ratio the oil phase diameter increases according to a sigmoid profile, stabilizing up to 340 min. The apparent viscosity decreases a minimum value with the shear rate, but increases with both the O/S ratio and the DOX incorporation in the system. The structural and rheological properties of the studied MEs were directly dependent on the O/S ratio and can be used to improve the application of the system in the pharmaceutical field.
已研究带负电荷的油包水（o/w）微乳液的结构和粘弹性特性。微乳液（ME）包含大豆卵磷脂（SPC）、Eumulgin HRE 40（EU）和油酸钠（SO）作为表面活性剂、胆固醇（CHO）作为油相以及含或不含抗癌药物阿霉素（DOX）的水性缓冲液。研究了油相/表面活性剂比（O/S）和 DOX 掺入对 ME 系统中几种组成的结构和流变性质的影响。通过振荡应力扫掠、蠕变恢复试验和粘度试验进行流变分析。DOX 掺入与高 O/S 比的结合提供了具有线性行为的进一步粘弹性结构。独立于 O/S 比，油相直径根据 S 形曲线增加，稳定至 340 分钟。表观粘度随剪切率降低至最小值，但随 O/S 比和 DOX 掺入系统而增加。所研究的 ME 的结构和流变性质直接取决于 O/S 比，可以用于改善该系统在制药领域的应用。
