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

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< or =.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.     

The stability of benzoyl peroxide by isothermal microcalorimetry

Isothermal microcalorimetry may be used to determine kinetic and thermodynamic parameters for chemical reactions. This paper reports rate constants, determined as a function of temperature, and the activation enthalpy for the degradation of solid benzoyl peroxide as determined by isothermal microcalorimetry. Studies were conducted on aqueous suspension phase, solid benzoyl peroxide. In addition, supporting evidence is cited from work carried out in this laboratory on the solution phase degradation of benzoyl peroxide using UV-visible spectrophotometry. The activation energy obtained by microcalorimetry was E(a)=137.8+/-6.6 kJ mol(-1) and the activation energy obtained from UV-visible spectrophotometry was E(a)=112.7+/-4.2 kJ mol(-1).     

Delayed type hypersensitivity to benzoyl peroxide

Benzoyl peroxide (BP) has been a standard and effective topical treatment for acne vulgaris for the past 35 years. Previous studies and case reports have documented benzoyl peroxide to be a strong irritant and a weak allergen, with many cases of tolerance induced with repeat use of this irritant. While less common, numerous cases of BP-induced allergic contact dermatitis (delayed type hypersensitivity reaction) have been reported in the literature. We report here an individual with an incipient edematous reaction to topical BP used for acne therapy. This under-recognized presentation is discussed in the context of published literature on BP-induced hypersensitivity and irritation.     

Selective assay of benzoyl peroxide in lotions and creams.

A selective titrimetric method for the determination of benzoyl peroxide in lotions and creams was developed. It is based on the work of Horner and Jürgens, in which diacylperoxides, dialkylperoxides, peracids, and alkylhydroperoxides can be determined selectively by iodometry and acidimetry. The proposed assay is stability indicating with respect to peracids. Good recovery data were obtained.     

过氧化苯甲酰测定方法研究

本文研究了用紫外分光光度法测定面粉及面制品中过氧化苯甲酰的方法。探讨了样品处理,还原、蒸馏、吸收光谱等条件。本法回收率:92—110%,CV6.3%.检出(?):0.02g/kg,检测范围:0—1.3g/kg。满足了正常监督监测工作的需要。     

Pentoxifylline in the treatment of venous leg ulcers.

A double-blind, placebo-controlled study was carried out in 12 patients suffering from chronic venous insufficiency and persistent leg ulcers to assess the efficacy of pentoxifylline treatment as an adjunct to compression bandaging in the conservative management of venous leg ulcers. Six patients were allocated at random to receive twice-daily infusions of 200 mg pentoxifylline intravenously and 400 mg pentoxifylline orally 3-times daily for 7 days then 400 mg oral doses 3-times daily for a further 60 days. The control group received matching placebo in an identical regimen. Treatment outcome was assessed by changes between the start and end of the study in venous ulcer surface area, and continuous wave Doppler ultrasound was used to monitor ankle/arm systolic pressure ratio, venous pressure at the ankle, valvular competence and possible venous reflux at intervals throughout the study period. The results showed that in the patients treated with pentoxifylline complete ulcer healing took place in 4 out of 6 and there was a significant reduction in mean ulcer surface area. In the control group, complete ulcer healing was recorded in 1 out of 6 patient only and the ulcer area was only moderately reduced in the others. There was no statistically significant differences between the two groups in the variables monitored by Doppler ultrasound but the difference between treatment outcome was significant. Treatment was well-tolerated.     

Stability of benzoyl peroxide in aromatic ester-containing topical formulations

The chemical stability of benzoyl peroxide (BPO) was studied in solutions and gels. The solutions (1% w/v) were prepared in single solvents (alcohol USP, isopropyl alcohol USP, ethyl benzoate, C12-15 alkyl benzoate, dimethyl isosorbide, propylene carbonate, and acetone) and in binary and tertiary combinations of these solvents, with and without the addition of antioxidant(s) (BHT, BHA, eugenol, tert-butyl hydroquinone, Tenox-2, vitamin E, and vitamin C). The solutions were stored at 37 degrees C for 5 weeks, and each week were analyzed for remaining BPO. Using first-order kinetics, the stability of BPO in solution was found to decrease in the order: ternary>binary>single solvent systems. Regardless of the number of solvents present, the highest stability of BPO (t1/2>7.5 weeks) was attained in the presence of ethyl benzoate and C12-15 alkyl benzoate. The stability of BPO in solution did not change significantly with the addition of most antioxidants. The solutions in which BPO remained most stable were one in alcohol USP-ethyl benzoate-C12-15 alkyl benzoate (60:20:20; t1/2=18.15 weeks) and another in alcohol USP-C12-15 alkyl benzoate-isopropanol plus 0.1% BHT (65:20:15; t1/2=12.44 weeks). In turn, these two solutions were converted to homogeneous gels by the addition of Cab-O-Sil. The chemical stability of BPO in these gels was evaluated at 37 degrees, 45 degrees, 50 degrees, and 55 degrees C for 5 weeks. Parallel experiments were conducted with two commercial BPO products, a 2.5% tinted gel and 5% vanishing lotion. BPO was less stable in commercial products (t1/2相似文献   

High-pressure liquid chromatographic assay of benzoyl peroxide in dermatological gels and lotions.

A high-pressure liquid chromatographic method for the assay of benzoyl peroxide in dermatological preparations is described. Degradation products such as benzoic acid and perbenzoic acid do not interfere. The method is simple, precise, accurate, and stability indicating.     

HPLC法测定祛痘类化妆品中的过氧化苯甲酰

目的建立高效液相色谱法测定祛痘除螨类化妆品中的过氧化苯甲酰的方法。方法采用ZORBAX C18柱,4．6×250mm．5μm;以甲醇-0．02mol·L^-1的醋酸铵溶液（80：20）为流动相;检测波长为230nm。结果过氧化苯甲酰在0．224μg·mL^-1～44．8μg·mL^-1范围内呈良好线性关系,r=0．9996．过氧化苯甲酰的平均回收率为95．94％．RSD％为2．5％。结论上述建立的方法简便易行、准确、重现性好,可用于祛痘类化妆品中禁用物质过氧化苯甲酰的检测。     

Role of the benzoyloxyl radical in DNA damage mediated by benzoyl peroxide.

Benzoyl peroxide (BzPO) is both a tumor promoter and progressor in mouse skin; however, BzPO is neither an initiator nor a complete carcinogen in this tissue. Although not mutagenic, BzPO has been observed to produce strand breaks in DNA of exposed cells. These actions are presumed to be mediated by free-radical derivatives of BzPO. Previous studies suggested that the metabolism of BzPO in keratinocytes proceeds via the initial cleavage of the peroxide bond, yielding benzoyloxy radicals which, in turn, can either fragment to form phenyl radicals and carbon dioxide or abstract H atoms from biomolecules to yield benzoic acid. Benzoic acid is the major stable metabolite of BzPO produced by keratinocytes. In the present study we have investigated the role of BzPO and its metabolites in the generation of strand scissions in a cell-free system using phi X-174 plasmid DNA. In this system BzPO produced DNA damage that was dose-dependent over a concentration range of 0.1-1 mM and required the presence of copper but not other transition metals. By contrast, benoic acid did not produce DNA damage in this system, either in the presence or in the absence of copper. The inclusion of spin trapping agents, such as N-tert-butyl-alpha-phenylnitrone (PBN), 3,5-dibromo-4-nitrosobenzenesulfonate, and nitrosobenzene, in incubations was found to significantly reduce the extent of DNA damage generated via the copper-mediated activation of BzPO. Electron paramagnetic resonance spectroscopy studies suggested that the primary radical trapped by PBN following copper-mediated decomposition of BzPO was the benzoyloxy radical.(ABSTRACT TRUNCATED AT 250 WORDS)     

Efficacy and safety of topical nadifloxacin and benzoyl peroxide versus clindamycin and benzoyl peroxide in acne vulgaris: A randomized controlled trial

Background:

Topical therapy with comedolytics and antibiotics are often advocated for mild and moderate severity acne vulgaris. Nadifloxacin, a new fluoroquinolone with anti-Propionibacterium acnes activity and additional anti-inflammatory activity, is approved for use in acne. This randomized controlled assessor blind trial compared the clinical effectiveness and safety of eight weeks therapy of nadifloxacin 1% versus clindamycin 1% as add-on therapy to benzoyl peroxide (2.5%) in mild to moderate grade acne.

Materials and Methods:

The efficacy parameters were changes in the total, inflammatory and non-inflammatory lesion counts, Investigator Global Assessment (IGA), and Cardiff Acne Disability Index (CADI) scales from baseline to study end (eight weeks). All treatment emergent dermatological adverse events were evaluated for safety assessment.

Results:

Out of 84 randomized subjects (43-nadifloxacin arm) and (41-clindamycin) 42 in nadifloxacin group, 37 in clindamycin group completed the study. Reduction from baseline of total, inflammatory and non-inflammatory lesion counts were highly significant in both the groups (P<0.0001), but between group differences were not significant. Significant improvement in CADI and IGA scales were noted in both groups. Between-group comparison showed no significant differences. The safety and tolerability profile of both regimens were good and statistically comparable.

Conclusions:

Topical nadifloxacin, a new fluoroquinolone is effective, tolerable, and safe for mild o moderate facial acne. Its clinical effectiveness is comparable to clindamycin when used as add-on therapy to benzoyl peroxide.KEY WORDS: Acne vulgaris, clindamycin, nadifloxacin, randomized controlled trial