Department of Pharmacy, University of Salerno, I-84084 Fisciano, SA, Italy; PhD Program in Drug Discovery and Development, University of Salerno, I-84084 Fisciano, SA, Italy.
Department of Pharmacy, University of Salerno, I-84084 Fisciano, SA, Italy.
Int J Biol Macromol. 2017 Aug;101:100-106. doi: 10.1016/j.ijbiomac.2017.03.077. Epub 2017 Mar 18.
Gelling solution parameters are some of the most important variables in ionotropic gelation and consequently influence the technological characteristics of the product. To date, only a few studies have focused on the simultaneous use of multiple cations as gelling agents. With the aim to deeply explore this possibility, in this research we investigated the effect of two divalent cations (Ca and Zn) on alginate beads formation and properties. Alginate beads containing prednisolone (P) as model drug were prepared by prilling technique. The main critical variables of the ionotropic gelation process i.e. composition of the aqueous feed solutions (sodium alginate and prednisolone concentration) and cross-linking conditions (Ca, Zn or Ca+Zn), were studied. The obtained beads were characterized and their in vitro release performances were assessed in conditions simulating the gastrointestinal environment. Results evidenced a synergistic effect of the two cations, affecting positively both the encapsulation efficiency and the ability of the alginate polymeric matrix to control the drug release. A Ca/Zn ratio of 4:1, in fact, exploited the Ca ability of establish quicker electrostatic interactions with guluronic groups of alginate and the Zn ability to establish covalent-like bonds with carboxylate groups of both guluronic and mannuronic moieties of alginate.
胶凝溶液参数是离子凝胶化中最重要的变量之一，因此会影响产品的技术特性。迄今为止，只有少数研究集中在同时使用多种阳离子作为胶凝剂。为了深入探索这种可能性，本研究考察了两种二价阳离子（Ca 和 Zn）对海藻酸盐珠形成和性能的影响。含有泼尼松龙（P）作为模型药物的海藻酸盐珠通过造粒技术制备。离子凝胶化过程的主要关键变量，即水相进料溶液（海藻酸钠和泼尼松龙浓度）和交联条件（Ca、Zn 或 Ca+Zn），进行了研究。所得珠粒进行了表征，并在模拟胃肠道环境的条件下评估了其体外释放性能。结果表明，两种阳离子具有协同作用，对包封效率和海藻酸盐聚合物基质控制药物释放的能力均产生了积极影响。事实上，Ca/Zn 比为 4:1 利用了 Ca 与海藻酸盐中古洛糖醛酸基团快速建立静电相互作用的能力，以及 Zn 与海藻酸盐中古洛糖醛酸和甘露糖醛酸部分的羧酸盐基团建立类似共价键的能力。
