The instrument of choiceoil in water formulas are light liquids or lotions that do not feel heavy on the skin. The majority of the formula is water which may evaporate on the skin and leave a small amount of oil. Water in oil formulas are heavy, greasy products consisting mostly of oil. Generally, water in oil products are developed for skin that has a good water content but requires more oil from a moisturizing product. Thermogravimetric analysis tga is an excellent tool for analyzing the moisture content of cosmetic skin creams. The results shown in the figure right were measured using the mettler toledo tgadsc 1 and evaluated using stare excellence software.
Samples of oil in water ow creams with different water contents were heated from 20 °c to 200 °c at a heating rate of 2 kmin in a nitrogen atmosphere. The tga curves indicate that all creams, with the exception of sample c, show a significant weight loss between 30 °c and 140 °c. The weight loss is caused by the evaporation of volatile components, especially water. The tgadsc 1 is a valuable instrument for product quality control within the cosmetics industry.
It provides excellent and reliable thermogravimetric measurement performance and high temperature accuracy. With the addition of the sample robot, hermetically sealed crucibles can be pierced immediately prior to measuring.this unique feature prevents the sample taking up or losing moisture between weighin and measurement. The tgadsc 1 also has the added benefit of simultaneous calorimetric analysis, which is of great benefit to cosmetics manufacturers.
