Stability of a Cosmetic Multiple Emulsion Loaded with Green Tea Extract

Table 3

Centrifugation, mean conductivity, and pH values of 5% green tea multiple emulsions kept at different storage conditions.

Time	8°C	25°C	40°C	40°C with 75% RH
pH*
24 h	5.13±0.06	5.48±0.03	5.31±0.04	5.41±0.02
48 h	5.11±0.04	5.46±0.35	5.12±0.08	5.36±0.24
07 d	5.70±0.06	5.44±0.07	5.02±0.08	5.29±0.16
15 d	5.55±0.32	5.41±0.36	5.05±0.05	5.28±0.08
30 d	5.56±0.08	5.34±0.06	5.09±0.03	5.35±0.09
Conductivity (μS/cm)**
24 h	14.2±2.50	7.93±1.10	9.70±1.81	9.30±1.59
48 h	14.7±2.60	9.30±2.95	9.90±2.65	9.76±2.01
07 d	15.3±2.45	11.3±1.81	10.8±1.42	10.0±2.05
15 d	15.5±1.70	11.5±1.15	11.4±2.06	10.3±0.50
30 d	15.6±0.61	11.2±0.78	9.37±0.38	11.7±0.81
Centrifugation/phase separation***
24 h	S	S	S	S
48 h	S	S	S	S
07 d	S	S	S	S
15 d	S	S	S	S
30 d	S	S	S	S

∗pH of fresh multiple emulsion = 5.31 ± 0.01; **conductivity of fresh multiple emulsion = 8.43 ± 0.21 μS/cm; ***centrifugation at 5000 rpm for 20 minutes for each sample; S: stable.