METHODS
Thirty-three healthy subjects ages 25-60 years with moderate facial
dyspigmentation defined as a score of 3 on a 5-point scale,
with 5 indicating severe, were enrolled in this 20-week single center
research study by Dermatology Consulting Services. Pregnant
or nursing females were excluded. Following completion of an
IRB-approved consent (Concordia Clinical Research Institutional
Review Board, New Jersey), eligible subjects were requested to
avoid excessive sun exposure and the use of artificial tanning
methods. All colored cosmetics remained unchanged during the
20 weeks of the study. Subjects with any active facial dermatoses
were excluded, as were those who possessed any hypersensitivity
to any of the study product ingredients. All study participants
were provided with a standardized cleanser and a SPF 30 sunscreen
for daily use.
Subjects were selected based on previous use of 4% hydroquinone
in combination with 0.025% tretinoin cream for a period
of 12 weeks and instructed to discontinue the use of prescription
combination. Following the cessation of hydroquinone
and tretinoin, all subjects were provided with a cosmeceutical
formulation for skin lightening (Advanced Pigment Corrector,
SkinCeuticals, L’Oreal, New Jersey) to use twice daily. The
goal was to determine if the cosmeceutical formulation could
maintain the dyspigmentation improvement produced by the
hydroquionone/tretinion prescription therapy.
All efficacy and tolerability grading occurred on an ordinal
5-point scale (0=none, 1=minimal, 2=mild, 3=moderate, 4=severe).
The following parameters were evaluated: dark spot
size, dark spot intensity, hyperpigmentation, visual and tactile
smoothness, skin tone clarity, skin tone evenness, firmness,
radiance, blotchiness, and overall appearance. Tolerability
was also assessed on the same 5-point ordinal scale where
the dermatologist investigator assessed erythema, edema,
dryness, and peeling while the subjects assessed stinging,
tingling, itching, and burning.
Bioinstrumentation was also performed at baseline, weeks
12 and 20 to evaluate the change in the skin moisturization
after the hydroquinone/tretinoin combination was discontinued
and the study skin lightening product was initiated. The
bioinstrumentation consisted of corneometry measurements
using a pin probe corneometer (Dermalab, Denmark). Digital
frontal, right, and left photographs (Nikon, Canfield Scientific,
New Jersey) were obtained at weeks 12 and 20.
RESULTS
Thirty-three of thirty-three subjects completed the study. No
tolerability issues were noted by the investigator or the subjects
with the study skin lightening preparation throughout the
entire duration of the study. No adverse events or adverse experiences
were reported.
An important finding attests to the moisturizing capabilities
of the cosmeceutical formulation, which are not commonly
observed with the hydroquinone/tretinoin combination and
often lead to premature termination of the prescription therapy.
The bio-instrumental analysis confirmed this outcome with
corneometry measurements, which were statistically significantly
increased at week 12 (P=0.043) and week 20 (P=0.004)
as compared to baseline. In addition to the instrumental
evaluation, differences in the skin smoothness were noted at
week 12 after discontinuation of the hydroquinone/tretinoin
combination as evident by the investigator rated statistically
significant improvement (P<0.001) in visual smoothness and
tactile smoothness. There was also a reduction in erythema
(P=0.029), peeling (P=0.002), and dryness (P=0.003) at week
12, as compared to baseline, indicating better tolerability. All
of these observations point to the superior moisturization
properties of the study skin lightening product, which might
result in enhanced patient compliance.
Further clinical efficacy was confirmed by additional improvement
in skin quality as observed at week 20 of the study. There
was continued statistically significant improvement in visual
smoothness (P<0.05) and tactile smoothness (P<0.05) with a
reduction in erythema, peeling, and dryness on week 20 as
compared to the baseline assessment. Moreover, statistically
significant improvement was seen in clarity (P=0.007), imperfections
(P=0.005), radiance (P=0.001), and firmness (P=0.009).
The improvement in all of these facial parameters was reflected
in an overall highly statistically significant improvement
at week 20 (P=0.001). The improvement in cosmetic attributes
reflects the enhanced moisturization of the cosmeceutical formulation
as compared to the prescription combination.
Finally, improvement in skin pigmentation continued after the
prescription regimen was discontinued and application of cosmetic
formulation ensued. There was statistically significant
improvement at week 20 in terms of even skin tone (P<0.001),
an assessment of overall skin color; spot intensity (P<0.001)
and spot size (P<0.05), an assessment of the darkness of
individual pigmented facial lesions; and overall hyperpigmentation
(P=0.002; Figure 1). These observations are important as
continued improvement in dyspigmentation was seen after discontinuation
of the hydroquione/tretinoin combination.
