3. Results and Discussion
3.1. Creaming Index
Figures 3 and 4 present the computed creaming index for Rosmarinus officinalis/Calendula officinalis oil-in-water cosmetic emulsions respectively.
The higher the creaming index value is, the more de- stabilized the emulsion is. In our occasion maximum value proportion of water is 80%. There are two general features in the evolution of creaming index: 1) as oil phase is enriched with oil extract, creaming rate de- creases; 2) as emulsifier concentration increases, cream- ing rate decreases.
More specific, Figure 3 represents creaming index value for Rosmarinus officinalis emulsions. For an emul- sion with 6 g GMS and Rosmarinus officinalis oil extract no sign of creaming was observed for the first 60 days after production. Yet, all other examined cases show some variability with time although none of the emul- sions reached the value of 80% representing the complete separation. Probably the emulsions were stabilized after having a metastable form. Separation of the two phases was almost complete in less than 20 days in the emul- sions with no addition of extracts, regardless GMS con- centration.
Same trends are also observed in Figure 4. Separation of the two phases was almost complete in less than 5 days in the emulsions with no addition of extracts.
Comparing Figures 3 and 4 the following comments can be made 1) Emulsions made up with Calendula offi- cinalis extracts are more stable than those made with Rosmarinus officinalis due to lower values of creaming index (results were not changed up to 30 days for Ca- lendula officinalis emulsions) 2) emulsions having oily extracts were the most stable in both cases.