ENZYMATICALLY GENERATED HYDROGEN PEROXIDE REDUCES ACNE LESIONS 5 5 days. Percent difference compared with the untreated site shows that the glucose oxi- dase formulation exhibited an improvement in acne that was slightly better than the 10% BP formulation however, the difference was not statistically signifi cant. Part II: long-term effect. The 6-week, in-use study results are described in Figures 3A and B. Count of the infl ammatory acne lesions (Figure 3A) shows that they resolve over time in untreated control sites, because of the normal immune defense system of the body. BP (2.5%) was signifi cantly effective (p 0.001) in reducing infl ammatory acne lesions after 2-, 4-, and 6-week use. Glucose oxidase formulation was also signifi cantly effective (p 0.001), although not as effective as 2.5% BP. Noninfl ammatory acne lesions (Figure 3B) were also signifi cantly reduced by 2.5% BP after 2-, 4-, and 6-week use (p 0.001). Glucose oxidase formulation was also signifi - cantly effective (p ≤ 0.05). DISCUSSION A major component to the etiology of acne vulgaris is the proliferation of P. acnes in the follicular duct (21) as supported by the benefi ts of both topical and oral antibiotics (13) to alleviate acne. Topical erythromycin, clindamycin, and tetracycline (24) have all shown Table I Survival Ability of Selected Microorganisms That Were Introduced into a Mix of 0.04% Glucose Oxidase and 0.36% Glucose Substrate Pools Inoculum 24 h 48 h Week 1 1 6.6 0 0 0 2 6.5 0 0 0 3 6.3 0 0 0 4 6.4 6.0 6.0 6.0 5 5.0 5.0 5.0 5.0 All numbers are expressed as log counts. Figure 1. (A) Effect of glucose oxidase and glucose on reduction of size of acne lesion. (B) Reduction of in- fl ammation of acne lesion. Size and infl ammation of the individual acne lesions was assessed every day for 5 days with treatment.

JOURNAL OF COSMETIC SCIENCE 6 effi cacy, whereas tetracyclines including doxycycline and minocycline are effective when taken orally (25–27). However, overuse of these antibiotics can lead to bacterial resistance (10) and have limited usefulness when used alone. One of the strongest antiseptics in common use is BP, which alone or in combination with other antibiotics can signifi cantly reduce acne lesions and infection (28,13), however, with side effects like skin drying (28). Hydrogen peroxide is a common antiseptic that is used diluted on skin to kill bacteria in a wound. It is a powerful oxidizing agent however, it can act as a reducing agent for strong oxidants. Formulation of stable treatment creams with this agent is a challenge because of its reactive nature. Nevertheless, it has been shown to be a successful agent for acne treat- ment when used in combination with adapalene with better tolerability profi le in compari- son with the combination of BP and adapalene (27). Another study has shown hydrogen peroxide to be as effective as BP in reducing both infl ammatory and noninfl ammatory acne vulgaris lesions in patients with mild-to-moderate disease, with a better local tolerability Figure 2. Area under the curves from Figures 1(A) and (B) showing a précis of the activity of each treatment on reduction of size and infl ammation of acne lesions. Figure 3. (A) Infl ammatory lesion count of the full face from a 6-week in-use study. (B) Noninfl ammatory lesion count of the full face.