Department of Chemistry and Biochemistry, Faculty of Science I, Lebanese University, Hadath, Beirut, Lebanon.
Department of Chemistry and Biotechnology, Faculty of Science, Engineering and Technology, Swinburne University of Technology, Melbourne, Australia.
J Pharm Sci. 2019 Jun;108(6):2153-2161. doi: 10.1016/j.xphs.2019.01.021. Epub 2019 Jan 29.
We report the colloidal characterization of halofantrine (Hf)-laden soybean oil fat emulsions. Hf increased the zeta potential, at all pH values, of the fat emulsions. Concomitant with this, the isoelectric point (i.e.p.) of the emulsion increased to higher pH values. The emulsion was destabilized by a small amount of Hf; interestingly, however, this was ameliorated by increasing the amount of Hf. The particle size and polydispersity of the fat emulsion reflected this with a small Hf concentration resulting in a significant increase in both particle size and polydispersity, but less so as the Hf concentration was increased. Emulsions lost stability as the pH approached the i.e.p. and this effect was greatest for the small Hf concentration emulsions. Cryogenic transmission electron microscopy showed the presence of beading or string-like behavior leading to gross distortions of the spherical shape for highly unstable emulsions. We conclude that to maintain good stability for Hf-laden soybean oil emulsions, the pH of the emulsion should be kept away from its i.e.p, and also that the drug concentration should be maintained at a relatively high value.
我们报告了载有卤泛群（Hf）的大豆油脂肪乳剂的胶体特性。Hf 增加了脂肪乳剂在所有 pH 值下的动电位。与此相伴的是，乳液的等电点（IEP）向更高的 pH 值移动。少量 Hf 会使乳液不稳定；然而，有趣的是，增加 Hf 的量可以改善这种情况。脂肪乳剂的粒径和多分散性反映了这一点，少量 Hf 会导致粒径和多分散性显著增加，但随着 Hf 浓度的增加，这种情况会减少。当 pH 值接近 IEP 时，乳液会失去稳定性，对于 Hf 浓度较低的乳液，这种影响最大。低温传输电子显微镜显示存在珠状或线状行为，导致高度不稳定的乳液的球形严重变形。我们得出结论，为了保持载有 Hf 的大豆油乳剂的良好稳定性，应将乳液的 pH 值保持在远离其 IEP 值的位置，并且还应将药物浓度保持在相对较高的水平。
