Abstract:
Background: Hyperpigmentation occurs due to the overproduction of melanin. As free radicals
promote melanogenesis, antioxidants are important to combat free radicals and normalize melanin
production and inhibition of tyrosinase enzyme leads to inhibition of the biosynthesis of melanin.
Considering these facts developing plant-based formulations to treat hyperpigmentation would be
beneficial due to least adverse effects.
Objectives: To formulate and evaluate a poly-herbal topical cream for hyperpigmentation by
incorporating scientifically evaluated roots extract of Glycyrrhiza glabra, leaves and pods extract
of Mimosa pudica for known antioxidant and tyrosinase inhibitory activities
Methods: Initially, three different cold and vanishing cream bases from each were prepared and
observed real-time and centrifugation stability for 14 days at 8°C, 28 ±5°C and 40°C temperatures
to observe any instability mechanism. The dose of each plant extract was calculated based on the
IC50 and LC50 values obtained for in-vitro biological assays and toxicology assays. Calculated
doses were incorporated into stable cream bases and kept evaluating real-time and centrifugation
stability for 90 days at the same temperatures at specified time intervals. The most physically
stable polyherbal cream was evaluated for physicochemical properties by measuring viscosity,
spreadability, pH, and homogeneity and observing organoleptic properties and cream type through
microscope.
Results: One cold cream base and all vanishing cream bases were stable throughout the 14 days at
the mentioned temperatures. Phase separation was the main instability mechanism observed in
unstable cold cream bases. The prepared poly-herbal cold cream was subjected to phase separation
soon after the centrifugation. However, all poly-herbal vanishing creams were stable throughout
the 90 days, and out of them, one vanishing cream was observed with better stability at three
temperatures. It was obtained with 54700 cps viscosity, 6.1 gcms-1
spreadability, 6.5 pH. Further,
it was an Oil-in-Water type homogeneous vanishing cream with a yellowish-white color and
smooth texture along with a pleasant odor.
Conclusion: It is concluded that the most stable poly-herbal vanishing cream will be
recommended for further studies including pre-clinical and clinical trials before
commercialization.
