Abstract
Background and aims: Multiple emulsions have excellent encapsulating potential and this investigation has been
aimed to encapsulate two different plant extracts as functional cosmetic agents in the W/O/W multiple emulsions
and the resultant system’s long term stability has been determined in the presence of a thickener, hydroxypropyl
methylcellulose (HPMC).
Methods: Multiple W/O/W emulsions have been generated using cetyl dimethicone copolyol as lipophilic
emulsifier and a blend of polyoxyethylene (20) cetyl ether and cetomacrogol 1000® as hydrophilic emulsifiers.
The generated multiple emulsions have been characterized with conductivity, pH, microscopic analysis, phase
separation and rheology for a period of 30 days. Moreover, long term shelf-storage stability has been tested to
understand the shelf-life by keeping the generated multiple emulsion formulations at 25 ± 10°C and at 40 ± 10%
relative humidity for a period of 12 months.
Results: It has been observed that the hydrophilic emulsifiers and HPMC have considerably improved the stability
of multiple emulsions for the followed period of 12 months at different storage conditions. These multiple
emulsions have shown improved entrapment efficiencies concluded on the release rate of conductometric tracer
entrapped in the inner aqueous phase of the multiple emulsions.
Conclusion: Multiple emulsions have been found to be stable for a longer period of time with promising
characteristics. Hence, stable multiple emulsions loaded with green tea and lotus extracts could be explored
for their cosmetic benefits.
Keywords: Green tea, Lotus, Nano, Multiple, Emulsions, Stability