Dead Sea For Cosmetics
Dead Sea salt and mud are known for their therapeutic and cosmetic properties. The presence of Dead Sea salt in different types of cosmetics has affected the stability and the flow properties of the finished products.
In a study, an attempt was made to find the optimum Dead Sea salt content in a cosmetic emulsion (model of body cream) using both rheology and stability measurement. the rheological properties were tested during a four-month storage period at three different storage temperatures 8C, room temperature and 4 5øC.I in addition to the rheological measurements and centrifuge tests, the conductivities of the emulsion samples were also determined.
The centrifuge tests showed that the cream samples containing more than 0.25 wt% of Dead Sea salt showed phase separation the addition of Dead Sea salt to the cosmetic emulsion led to two maxima in the emulsion viscosity at salt contents of 0.07 wt % and 0.15 wt%. However, the emulsion samples containing 0 .15% of Dead Sea salt was considered the optimum sample since it contained the maximum amount of salt and exhibited the maximum viscosity at all tested conditions. It was found that the viscosity of the emulsion is increased with storage time and storage temperature. This behavior was accompanied by a decrease in conductivity. This behavior was explained by water evaporation from the emulsion.
However, it has been shown that the presence of Dead Sea salt in the cosmetic emulsion significantly reduces the rate of water evaporation. The conductivity measurements reflect the rate of water evaporation, and the presence of Dead Sea salt reduces the rate of conductivity. Conductivity is observed to decrease with storage time and temperature.