Solubilized Benzoyl peroxide versus Benzoyl peroxide/clindamycin in the treatment of moderate acne

Journal of Drugs in Dermatology, June, 2008 by Emil Tanghetti, Leon Kircik, David Wilson, Sunil Dhawan

Abstract

Background: Benzoyl peroxide (BPO) is poorly soluble. A solubilized formulation of BPO has been developed to maximize its bioavailability and enhance follicular penetration

Methods: Patients with acne vulgaris were randomly assigned to receive solubilized BPO 5% gel on one side of the face and a BPO 5%/clindamycin 1% combination product on the contralateral side, twice daily for 4 weeks.

Results: Of 23 patients enrolled, 100% completed the study. Reductions in lesion count with the solubilized BPO gel were at least as great as with BPO/clindamycin--and significantly greater (P< 05) for noninflammatory lesions at week 1 and inflammatory lesions at week 4- Both regimens were generally well tolerated and patient satisfaction was comparable.

Conclusions: Solubilized BPO 5% gel monotherapy offers significantly greater efficacy, and comparable patient satisfaction, compared with BPO/clindamycin. The early reduction in lesion counts observed with the solubilized BPO gel in the absence of an antibiotic is clinically relevant.

Introduction

Benzoyl peroxide (BPO) can be effective in the treatment of both inflammatory and noninflammatory acne lesions, (1) presumably as a result of its antibacterial and comedolytic activities. It has a key advantage over antibiotics as it is not associated with the development of bacterial resistance. (2) However, BPO is poorly soluble and molecules tend to aggregate together to form crystalline clusters. Commercially available formulations of BPO are generally emulsions of these clusters of which most of the BPO is trapped in the interior of the clusters. As a result, the bioavailability of BPO, and its ability to interact with Projnonihacteriinn acnes (P acnes), is compromised. The size of the clusters can also hinder their passage into hair follicles and, in addition, some commercially successful formulations have vehicles that further inhibit the ability of BPO to penetrate inside hair follicles.

Using a patented technology, 2 novel formulations of solu bilized BPO 5% (a gel and a lotion) have now been developed that aim to maximize the bioavailability of BPO and enhance its follicular penetration. In a split-face randomized study evaluating intrafollicular bactericidal activity, the solubilized BPO 5% was shown to achieve a greater reduction in colony forming units of P acnes at 8 hours after application than either a prescription generic BPO 5% product or a prescription BPO 5%/antibiotic combination product (log10 reductions of 1.9 solubilized BPO versus 1.7 generic BPO, and 2,5 solubilized BPO versus 1.7 BPO/antibiotic).5 Furthermore, in a split-face randomized study evaluating skin surface bactericidal activity, the solubilized BPO 5% formulation again achieved a greater reduction in colony forming units of P acnes than the BPO 5%/antibiotic combination product (logic reductions of 2.8 BPO 5% versus 2.4 BPO/antibiotic on the cheeks; and 3.0 BPO 5% versus 2.9 BPO/antibiotic on the forehead).

The solubilized BPO 5% formulations are now available as part of 3-step acne systems (Clenziderm MD)[TM]--the gel formulation for normal to oily skin and the lotion formulation for normal to dry skin, (The 3-stcp acne system for normal to oily skin also incorporates the use of a proprietary toner and cleanser, both of which contain salicylic acid 2%. The 3-step acne system for normal to dry skin also incorporates the use of a proprietary gentle cream cleanser and a proprietary therapeutic moisturizer containing glycerin and dime-tbicone.)

The study was designed to compare the clinical efficacy and tolerability of solubilized BPO 5% gel monotherapy (ie, without the other components of the 3-step acne system) with a leading prescription 5% BPO/clindamycin combination product in patients with moderate facial acne vulgaris.

Methods

Study Design

Twenty-three patients enrolled in a 4-week, multicenter, investigator-blinded, randomized, split-face study. Eligible subjects ptesented with moderate facial acne vulgaris (25-100 noninflammatory lesions, 25-100 inflammatory- lesions, up to 2 nodulocystic lesions) and were 11 to 45 years of age. Study subjects were also required to be willing to refrain from using nonstudy acne medications, moisturizers, sunscreens, fragrances, aftershaves, and make-up on the face (oil-free non comedogenic make-up, mascara, eyeshadow, and lipstick were allowed). Patients were also required to be willing to avoid excessive exposure to the sun and the use of tanning booths.

Key exclusion criteria included: having undergone a facial cosmetic procedure in the preceding 6 months; an allergy to BPO, clindamycin, lincomycin, salicylic acid, sunscreens or other ingredients in the study products; papulopustular rosacea or other skin diseases on the face (other than acne) that could interfere with study evaluations; facial sunburn at the baseline visit; males with facial hair that could interfere with study evaluations; uncontrolled systemic disease or infection with human immunodeficiency virus; history of regional enteritis, ulcerative colitis, or antibiotic-associated colitis; concurrent facial use of other medicated products; and participation in an investigational study in the preceding 30 days.