Abstract
The objective of this study was to
evaluate the antioxidant activities and cytotoxicity effect on normal human
dermal fibroblasts of roselle (Hibiscus sabdariffa L.) calyx extracts and
to load with the roselle extract in the inner phase of water in oil in water
multiple emulsion for application in facial cosmetic. The extracts of dried roselle
calyces were prepared by a maceration technique using ethanol/water
at concentrations of 30%, 70%, 95% and 0% (100% DI water). Obtained results showed
that the 30% ethanolic extract had a higher amount of total phenolic and anthocyanin
content than other extracts. According to the DPPH and ABTS assays, the 30%
ethanolic extract exhibited dose-dependent antioxidant activity higher than
other extracts with an IC50 value of 0.432±0.001 mg/mL and 0.0855±0.01
mg/mL, respectively. The formulation of water in oil in water multiple emulsion
containing the roselle calyx extract was prepared by a beaker method with
two-step emulsification. The prepared multiple emulsion showed a light pink color
with homogeneously formula. The physiochemical stability of the prepared formula
was evaluated at accelerated conditions; room temperature (30±5ºC), low
temperature (4±1ºC) and high temperature (40±1ºC) for 30 days and 6 cycles of
freeze (-25ºC, 24 h)-thaw (4ºC, 24 h). Results found that the tested formula
showed a good physicochemical stability compared to the initial condition. All
finding suggests possible application for the 30% ethanolic extract of roselle
calyces as a natural active ingredient in skin cosmetic products.
Keywords: Water in oil in water emulsion, Roselle calyx
extracts, Antioxidation activity, Cytotoxicity study