INTRODUCTION
The treatment of facial dyspigmentation requires persistence
and diligence on the part of the dermatologist and
the patient. The current standard prescription therapy
of 4% hydroquinone requires at least 3 months to obtain clinical
results, but enhanced efficacy can sometimes be achieved by
combining the 4% hydroquinone with 0.025% tretinoin.7 There is
some controversy as to how long subjects can safely use hydroquinone
and the barrier damage induced by combination therapy
can decrease patient compliance.2 Further concerns regarding the
safety of long-term hydroquinone use have been raised by both
dermatologists and the FDA.8 These concerns have led researchers
to examine other options that might allow initial treatment
with hydroquinone followed by maintenance therapy with a cosmeceutical
formulation. Hydroquinone inhibits melanin production
by inhibiting tyrosinase, the key enzymatic step in melanin
production.9 Its activity can be augmented by 0.025% tretinoin,
which inhibits the transfer of melanin to keratinocytes, and also
functions as a penetration enhancer for the hydroquinone through
barrier degradation.6 The barrier degradation accounts for much
of the peeling, stinging, and burning some subjects experience
with combination treatment. This research examined the use of a
novel hyperpigmentation formulation on subjects who have previously
completed 12 weeks of treatment with 4% hydroquinone
and 0.025% retinoic acid. This formulation contained hydroxyphenoxy
propionic acid, ellagic acid, yeast extract, and salicylic acid.
These active ingredients were specifically chosen to target different
layers of the skin for more comprehensive disruption of the
pigment pathway and pigment distribution. In a previous study, it
was established that the novel formula attained equivalent clinical
benefits as 4% hydroquinone and 0.025% tretinoin.1
Hydroxyphenoxy propionic acid inhibits melanin production from
cultured B16 cells without affecting melanocyte viability.10 In addition,
it inhibits melanosomes transfer to the keratinocytes. It is
combined with ellagic acid, a naturally occurring compound found
in fruits and berries, to block excess melanin production by inhibiting
tyrosinase at the basal layer with an added function as an
anti-inflammatory.11,12 Yeast extract, derived from saccharmoyces
cerevisiae, functions in the stimulation of lysosomal degradation
of keratinocytes to speed melanin degradation and removal while
stimulating fibroblasts in the dermis aiding the skin’s resistance to
formation of new pigment.13 Finally, salicylic acid functions as a
penetration enhancer, while also exfoliating the skin to aid in the
desquamation of existing pigment containing keratinocytes.
The goal of this study was to evaluate the skin lightening and
tolerability profile of a 20-week maintanence therapy with a
cosmeceutical formulation during the summer months. The primary
objective was to determine the ability of the cosmeceutical
formulation to maintain the attained reduction in hyperpigmentation
parameters and offer additional improvements in skin
quality as measured by a validated investigator assessment.
