Abstract：
Ionotropic gelation is a low-cost, easy and green microencapsulation technique. However, the encapsulation of highly soluble compounds is challenging because of the wide loss of material into the external water phase by passive diffusion and the consequent low encapsulation efficiency. In this work an important increase of encapsulation efficiency for Thymus vulgaris L. aqueous extract in alginate-based microparticles has been obtained. A formulation with the proper thyme extract/alginate ratio (30:70) was used as reference and then optimized by adding different co-carrier excipients. Microparticles obtained by dropping a solution containing thyme extract and alginate into a chitosan/calcium-chloride/acid acetic solution lead to a high encapsulation efficiency (70.43 ± 5.28 %). After drying, microparticles had a particle size of 1096 ± 72 μm, 20.087 ± 1.487 % of extract content, 6.2 % of residual water, and showed a complete release of thyme extract within one hour. Combining alginate and chitosan as polymeric co-carrier was a valuable option for efficiently encapsulating an aqueous extract by ionotropic gelation.
摘要：
离子凝胶化是一种低成本，简单和绿色的微囊化技术。然而,高可溶性化合物的封装是具有挑战性的,因为材料由于被动扩散而广泛损失到外部水相中,并且因此封装效率低。在这项工作中，已经获得了基于海藻酸盐的微粒中胸腺的水提取物的包封效率的重要提高。具有适当百里香提取物/藻酸盐比例(70:30)的制剂用作参考,然后通过添加不同的共载体赋形剂来优化。通过将含有百里香提取物和藻酸盐的溶液滴入壳聚糖/氯化钙/酸性乙酸溶液中获得的微粒导致高的包封效率（70.43±5.28％）。干燥后,微粒的粒径为1096±72μm，提取物含量的20.087±1.487%，6.2%的残余水，并显示百里香提取物在一小时内完全释放。结合海藻酸盐和壳聚糖作为聚合物共载体是通过离子凝胶化有效包封水性提取物的有价值的选择。
