Abstract An essential first step to deep into the knowledge of the mechanisms of action that underlie the use of clay-based spring water gels is their design and development according to standardized protocols and procedures. Hydrogels with two spring waters and two clay excipients, sepiolite (PS9) and palygorskite (G30), were studied. The excipients were fully characterized as regards their identity, purity and richness, as well as their textural features, cation exchange capacities and zeta-potential. Conductivity, pH and ionic composition of spring waters were also assessed. Rheological and thermal properties of hydrogels were monitored through time. PS9 complied with identity, richness and purity descriptions of “Magnesium silicate” (or “Magnesium trisilicate”) United States and European Pharmacopoeia monographs', whereas G30 satisfied “Attapulgite” monograph. Cooling rates of 10% w/w spring water hydrogels were adequate for topical application as thermotherapic agents. Gel-like systems obtained with PS9 showed higher viscosities and yield values than G30 hydrogels, the type of spring water not exerting significant influence. The properties remained almost constant during a period of 2 months, ensuring quality standards. Longer periods resulted in unforeseeable changes in properties ascribed to water losses.

中文翻译：

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天然无机赋形剂泉水水凝胶的设计与表征

摘要 要深入了解基于粘土的泉水凝胶的作用机制知识，必不可少的第一步是根据标准化协议和程序对其进行设计和开发。研究了具有两种泉水和两种粘土赋形剂海泡石 (PS9) 和坡缕石 (G30) 的水凝胶。赋形剂的特性、纯度和丰富度，以及它们的结构特征、阳离子交换能力和 zeta 电位都得到了充分的表征。还评估了泉水的电导率、pH 值和离子组成。通过时间监测水凝胶的流变学和热学性质。PS9符合“硅酸镁”（或“三硅酸镁”）美国和欧洲药典专论的特性、丰富度和纯度描述，而 G30 满足“凹凸棒石”专着。10% w/w 泉水水凝胶的冷却速率足以作为热疗剂局部应用。用 PS9 获得的凝胶状系统比 G30 水凝胶具有更高的粘度和屈服值，泉水的类型没有产生显着影响。在 2 个月的时间里，这些特性几乎保持不变，确保了质量标准。更长的时间会导致由于失水而导致的不可预见的变化。在 2 个月的时间里，这些特性几乎保持不变，确保了质量标准。更长的时间会导致由于失水而导致的不可预见的变化。在 2 个月的时间里，这些特性几乎保持不变，确保了质量标准。更长的时间会导致由于失水而导致的不可预见的变化。