Emulsions are thermodynamically unstable systems, they are mixtures of two immiscible phases intended to be dispersed one into the other. The main goal is to keep this dispersion stable for long time. When formulating emulsions, the preliminary tests, also known as formulation tests, constitute a step which can be long and expensive because of the quantity of reagents that can be used. A rigorous methodology could thus be of great interest, that is at the aim of our study which consists of evaluating the physico-chemical parameters of different phases used to make thus multiple emulsions. In our study, physico-chemical parameters such as conductivity, pH, density, viscosity, and surface tension have been studied by direct measurement using equipment and also by means of suitable mounting. The results showed that the pH and the surface tension have an important role in the prediction of the stability of emulsions, these latter must be of the same order of magnitude. For all phases conductivity does not have too much interest apart from helping to determine the type of the emulsion.

中文翻译：

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多种乳剂可用于口服活性成分药物成分：不同阶段的理化参数研究

乳剂是热力学不稳定的系统，它们是两种不混溶相的混合物，意在将它们彼此分散。主要目标是保持此分散体长期稳定。在配制乳液时，由于可以使用的试剂数量众多，因此初步测试（也称为配方测试）构成了一个步骤，该步骤可能很长且很昂贵。因此，一种严格的方法学可能引起人们的极大兴趣，这就是我们研究的目的，其中包括评估用于制备多种乳液的不同相的理化参数。在我们的研究中，通过使用设备直接测量以及通过合适的安装方式，研究了诸如电导率，pH，密度，粘度和表面张力等物理化学参数。结果表明，pH值和表面张力在乳液稳定性的预测中具有重要作用，后者的大小必须相同。对于所有相，电导率除了有助于确定乳液的类型外，没有太大的意义。