Evaluation of a Prescription Strength 4% Hydroquinone/10% L-Ascorbic Acid Treatment System for Normal to Oily Skin

December 2011 | Volume 10 | Issue 12 | Original Article | 1455 | Copyright © December 2011


Suzanne Bruce MDa and JoAnne Watson DPMb

aSuzanne Bruce and Associates, PA, Houston, TX bOMP, Inc., Long Beach, CA

RESULTS

Patients

Of 34 patients enrolled, 30 (88%) completed. Three discontinued due to mild facial adverse events and 1 withdrew voluntarily. The mean age of the patients was 32 years. The majority (88%) were Fitzpatrick skin type II-IV, with 82% being Caucasian, 12% Asian, and 6% black. In terms of the Glogau photodamage classification, 27% were type I, and 74% were type II.

Efficacy

At weeks 4, 6, and 12, respectively, the investigator evaluations showed that the proportion of patients showing at least a 1-grade improvement from baseline was: 7%, 47%, and 80% for the overall integrated assessment of photodamage; 30%, 60%, and 87% for the overall intensity of facial pigmentation; 10%, 30%, and 50% for fine lines and wrinkles; 57%, 87%, and 90% for tactile roughness; and 7%, 10%, and 33% for laxity (Figures 1-4). With each of these parameters, median scores showed significant improvements relative to baseline values: at all three timepoints for tactile roughness and overall intensity of pigmentation; at weeks 6 and 12 for the overall integrated assessment of photodamage and for fine lines and wrinkles; and at week 12 for laxity (Figures 1-4). In addition, at week 12, 90% of patients had achieved at least a moderate (˜50%) global improvement and 87% had achieved at least a moderate (˜50%) increase in lightness/brightness of the skin.
A high proportion of patients strongly agreed or somewhat agreed that: their skin was smoother (93% at week 4, 97% at week 12); their skin felt softer (90% at week 4, 93% at week 12); the treatment system was easy to apply (90% at week 4, 93% at week 12); their skin had a more even color tone (76% at week 4, 90% at week 12); their skin appeared more radiant (87% at week 4, 90% at week 12); and there was a visible reduction in their fine lines and wrinkles (57% at week 4, 87% at week 12) (Figure 5). At weeks 4 and 12, respectively, 80% and 97% of patients considered the overall appearance of their skin to be at least moderately improved; 83% and 97% considered the efficacy of the treatment system to be excellent, very good, or good; and 86% and 100% considered the treatment system to be excellent, very good, or good when compared with other skin care treatments they had used previously.
Photographic documentation of the improvement in facial appearance attained in two patients is shown in Figure 6.

Patient Satisfaction

The proportion of patients who were satisfied or very satisfied with the overall appearance of their skin increased from 90% at week 4 to 100% at week 12.

Tolerability

Adverse events that were probably or definitely related to treatment were facial skin dryness (incidence of 32%), erythema (9%), peeling (9%), pruritus (6%), milia (6%), rash (3%), burning sensation (3%), contact dermatitis (3%), and acne (3%). All adverse events were mild and they were most likely to occur in the first week of treatment. Of the 25 reports of adverse events that were at least probably related to treatment, 16 occurred in the 1st week (5 dryness, 3 redness, 2 peeling, 2 milia, 1 rash, 1 pruritus, 1 contact dermatitis, 1 burning sensation), 5 in the 2nd week (4 dryness, 1 acne), 2 in the 4th week (dryness, pruritus), and 2 in the 5th week (dryness, peeling). Among these 25 reports of adverse events, 22 resolved during the study period (with continued, uninterrupted treatment). Two patients had adverse events that had not resolved by the end of the study (2 dryness, 1 peeling).
Three patients discontinued due to facial adverse events (dryness, erythema/pruritus/dryness/rash, and contact dermatitis, respectively). The other subjects did not reduce or interrupt dosing.

DISCUSSION

The results of this study show that use of the 4% hydroquinone/ 10% L-ascorbic acid treatment system is associated with improvements in the overall appearance of the skin as well as in multiple specific parameters (pigmentation, fine lines and wrinkles, tactile roughness, laxity, lightness/brightness, smoothness, softness, evenness of color tone, and radiance).
Importantly, 100 percent of the patients were satisfied or very satisfied with the overall appearance of their skin at the end of the study. This high rate of patient satisfaction is likely a reflection of the ease of application of the treatment system and the fact that the vast majority of patients observed improvements in their skin-at the end of the study, 97 percent reported the appearance of their skin to be at least moderately improved, 97 percent considered their skin was smoother, 93 percent considered their skin felt softer, 90 percent considered their skin was more evenly toned, 90 percent considered their skin was more radiant, and 87 percent reported a visible reduction in fine lines, and wrinkles. The high rate of patient satisfaction also likely reflects the fact that at the end of the study 100 percent of the patients considered the system was good, very good, or excellent compared with other treatments they had used previously.
The favorable comparisons with other skin care treatments may also be partly attributable to the study product being a treatment system or "kit," a concept that has become very popular in dermatology in recent years, particularly in the treatment of acne. The popularity of such systems is thought to be at least partly due to their convenience in providing a complete skin care regimen which cares for the skin generally while also providing treatment for a specific condition such as photodamage (in this study) or acne. Importantly, another potential benefit of treatment systems is that they may enhance compliance1 and, ultimately, this could enhance efficacy.