Centre for Formulation Engineering, School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
Int J Cosmet Sci. 2011 Jun;33(3):263-8. doi: 10.1111/j.1468-2494.2010.00624.x. Epub 2011 Jan 27.
The addition of water to lipsticks in the form of a water-in-oil emulsion is an attractive opportunity for cosmetics manufacturers to deliver hydrophilic molecules to the consumers, as well as improving the moisturizing properties. In this work, the effect of the emulsifier type and water content on the structural properties of the designed products was investigated. It has been shown that PGPR leads to smaller droplets than the other emulsifiers tested. This was attributed to the ability of PGPR to form elastic interfaces that slow the coalescence between droplets during the process. It was also observed that crystals of wax tend to form structures at the interface upon cooling that prevent coalescence during storage. These structures also prevent leakage of water into the continuous phase. No effect of the water content on the melting properties of the emulsions was observed. Upon addition of more than 10% water, softening of the material was measured, due to the overall decrease in solid content. Addition of crystalline material (hard paraffin) was successfully used to reinstate the material properties.
将水以水包油乳液的形式添加到口红中，为化妆品制造商向消费者提供亲水分子并改善保湿性能提供了一个有吸引力的机会。在这项工作中，研究了乳化剂类型和含水量对设计产品结构特性的影响。结果表明，PGPR 比其他测试的乳化剂产生更小的液滴。这归因于 PGPR 形成弹性界面的能力，该能力在过程中减缓液滴之间的聚结。还观察到，在冷却时，蜡晶倾向于在界面上形成阻止储存过程中聚结的结构。这些结构还防止水渗入连续相。观察到含水量对乳液的熔融性能没有影响。当添加超过 10%的水时，由于固体含量的整体减少，测量到材料的软化。添加结晶材料（硬石蜡）成功地用于恢复材料性能。
