Background: Insulin has been included in a variety of dosage forms; nevertheless, liposomes have shown protection to degradation and better absorption. The addition of surfactant to liposomes could give the ability to deform and pass through intact membranes, and could increase the stability and the release of the drug.

Introduction: Due to the limitations of the current treatment of insulin in diabetic patients, investigation in alternatives routes has increased. The oral route is the most convenient because of the similarity with the natural secretion of this hormone. The aim was to evaluate the in-vivo effect of fourteen formulations of Insulin-loaded flexible liposomes with different surfactants by oral and subcutaneous routes.

Methods: Fourteen formulations of insulin were obtained with the addition of different surfactants. Size distribution, polydispersion index and Z potential were obtained for all formulations. In-vivo tests were performed in rats induced with experimental diabetes with streptozotocin, and glucose curves were obtained during 480 minutes.

Results: All formulations by the subcutaneous route caused an optimal reduction in glucose levels. However, the addition of Brij L23 produced a better reduction, lasting for 420 minutes. By the oral route, the reduction of glucose did not reach the normal levels, but the addition of Poloxamer 407 and Brij S10 showed the best reduction in the glucose levels by this route.

Conclusion: The addition of surfactants to the lipid structure can modify the release of the insulin by different routes of administration, but this behavior depends on the characteristics of the surfactant, such as the melting phase transition temperature of the lipid bilayer.

背景：胰岛素已包含在多种剂型中。然而，脂质体已显示出对降解和更好吸收的保护作用。在脂质体中添加表面活性剂可以赋予变形和穿过完整膜的能力，并且可以增加药物的稳定性和释放。

简介：由于当前糖尿病患者胰岛素治疗的局限性，替代途径的研究有所增加。口服途径是最方便的，因为与该激素的自然分泌相似。目的是通过口服和皮下途径评估十四种不同表面活性剂的胰岛素负载柔性脂质体的体内作用。

方法：通过添加不同的表面活性剂获得十四种胰岛素制剂。获得了所有制剂的尺寸分布，多分散指数和Z电位。用链脲佐菌素对实验性糖尿病诱发的大鼠进行体内测试，并在480分钟内获得葡萄糖曲线。

结果：所有通过皮下途径的制剂均导致葡萄糖水平的最佳降低。但是，加入Brij L23的还原效果更好，可持续420分钟。通过口服途径，葡萄糖的降低未达到正常水平，但是添加泊洛沙姆407和Brij S10显示通过该途径的葡萄糖水平的最佳降低。

结论：在脂质结构中添加表面活性剂可以通过不同的给药途径改变胰岛素的释放，但是这种行为取决于表面活性剂的特性，例如脂质双层的熔融相转变温度。