The ideal protective material should be colorless and should not give fragrance and taste to the preparation included in. It should not be volatile, thus it should not lose its effectiveness even if it is exposed to high temperatures during production and use.

Also, the protective material should continue its effectiveness in the product and should be compatible with the other materials in the formulation.

pH; In the cosmetic products pH provides a suitable environment for the microorganism growth. pH 5.5-8.0 is suitable for the reproduction of bacteria, pH 3.5 and lower pH are suitable for the yeast and fungi reproducing in more acidic environments and those pH values are seen in cosmetic products. The protective materials in the cosmetic products are desired to be effective in pH 2-11.

Temperature: The protective materials used in the cosmetic products should be resistant to the temperature they encounter in different formulation processes and use.

Resistance to Temperature: Those test are desired for the cream and other liquid or semi-solid preparations. It is made by changing the temperature from -30°C to room temperature for 24 hours period. This test, which should be done at least for 6 cycles, is used for the evaluation of the resistance to temperature changes. By using the control preparations, the situations such as emulsion stability, crystallization, precipitation, and turbidity are being analyzed.
Mechanical Tests; Those tests, made by using a suitable vibrator tool in a short time such as for a couple of hours, are used for the determination of the situation of the product during transport and storage. Test is applied by using different vibration speeds with different speeds. Centrifuge process gives an idea about the creaming and phase separation tendencies of the product emulsions.

Humidity; It is not enough to make the accelerated stability studies only in high temperatures, it also necessary to study in high humidity conditions. The test is made in 80% humidity and 37°C temperature in maximum. The aim of those tests is to provide the understanding of whether the stability of the product will change in different countries or climates or not.

Light Tests; Light tests should be made for the products which are exposed to light in the shelves presented for sale. The apparent change in the products with the light is the change in color. Sun light and sun cabinets are being used in the light tests. But, instead of the incoherent effects of the sunlight, sun cabinets which have stable energy and light intensity are being used.

Physical Analyses
The physical analyses made in our institution;
Absorption Time
Pressure Resistance Test
Bleed Number
Dye Spot Search Test
Brix (Solid material precipitating in water)
Turbidity
Structural Defect Test
Filling Quantity
Falling Test
Low Temperature Resistance
On Sieving
Appearance
Volume Examination
Light Absorbance Measurement
Thickness Measurement
Capacity
Boiling Water Resistance,
Organoleptic Examination
Dry Water Resistance
Specific Heat
pH
Color
Moisture
Impermeability
Stability
Water Temperature Change Resistance
Structure
Volatile Material Quantity
Composition
Washing Test
Density
Melting Point
Relative Density
Viscosity
Moisture Holding Capacity
pH of the skin
Foaming Experiment
% of moisture and volatile material
Insoluble Material
Material which is Insoluble in Water
Corrosion Effect Analysis
% of the volatile materials at 105°C
% of unsaponified material and the material which cannot saponify
Foam height, cm