Chloroxylenol and zinc oxide containing cream (Nels cream) vs. 5% benzoyl peroxide cream in the treatment of acne vulgaris. A double-blind, randomized, controlled trial

Zinc and Zinc Transporters in Dermatology

Zinc is an important trace mineral in the human body and a daily intake of zinc is required to maintain a healthy status. Over the past decades, zinc has been used in formulating topical and systemic therapies for various skin disorders owing to its wound healing and antimicrobial properties. Zinc transporters play a major role in maintaining the integrity of the integumentary system by controlling zinc homeostasis within dermal layers. Mutations and abnormal function of zinc-transporting proteins can lead to disease development, such as spondylocheirodysplastic Ehlers-Danlos syndrome (SCD-EDS) and acrodermatitis enteropathica (AE) which can be fatal if left untreated. This review discusses the layers of the skin, the importance of zinc and zinc transporters in each layer, and the various skin disorders caused by zinc deficiency, in addition to zinc-containing compounds used for treating different skin disorders and skin protection.

Comparative Efficacy of Pharmacological and Nonpharmacological Interventions for Acne Vulgaris: A Network Meta-Analysis

Acne has several effects on physical symptoms, but the main impacts are on the quality of life, which can be improved by treatment. There are several acne treatments but less evidence comparing their relative efficacy. Thus, we assessed the comparative efficacy of pharmacological and nonpharmacological interventions for acne. We searched PubMed, Embase, and the Cochrane Central Register of Controlled Trials from inception to April 2019, to include randomized controlled trials for acne that compared topical antibiotics (TA), benzoyl peroxide (BPO), topical retinoids (TR), oral antibiotics (OA), lasers, light devices including LED device (LED), photodynamic therapy (PDT), and intense pulsed light, chemical peels (CP), miscellaneous therapies or complementary and alternative medicine (MTCAM), or their combinations. We performed Bayesian network meta-analysis with random effects for all treatments compared with placebo and each other. Mean differences (MDs) of lesions count and risk ratios of adverse events with their 95% credible intervals (CrIs) were calculated, and all interventions were ranked by the Surface Under the Cumulative Ranking (SUCRA) values. Additional frequentist additive network meta-analysis was performed to detect the robustness of results and potential interaction effects. Sensitivity analyses were carried out with different priors, and metaregression was to adjust for nine potential effect modifiers. In the result, seventy-three randomized controlled trials (27,745 patients with mild to moderate acne), comparing 30 grouped intervention categories, were included with low to moderate risk of bias. For adverse effects, OA had more risk in combination treatment with others. For noninflammatory lesions reduction, seventeen interventions had significant differences comparing with placebo and three interventions (TR+BPO: MD = −21.89, 95%CrI [−28.97, −14.76]; TR+BPO+MTCAM: −22.48 [−34.13, −10.70]; TA+BPO+CP: −20.63 [−33.97, −7.13]) were superior to others with 94, 94, and 91% SUCRA values, respectively. For inflammatory lesions reduction, nineteen interventions were significantly better than placebo, and three interventions (TR+BPO: MD = −12.13, 95%CrI [−18.41, −5.80]; TR+BPO+MTCAM: −13.21 [−.39, −3.04]; LED: −11.30 [−18.34, −4.42]) were superior to others (SUCRA: 81, 81, and 77%, respectively). In summary of noninflammatory and inflammatory lesions results, TR+BPO and TA+BPO were the best options compared to others. The frequentist model showed similar results as above. In summary, current evidence supports the suggestion that TR+BPO and TA+BPO are the best options for mild to moderate acne. LED is another option for inflammatory lesions when drug resistance occurs. All the combinations involved with OA showed more risk of adverse events than others. However, the evidence of this study should be cautiously used due to the limitations.

Serum zinc levels and efficacy of zinc treatment in acne vulgaris: A systematic review and meta-analysis

Oral and topical zinc have been used for the treatment of acne, but there is a lack of definitive evidence for their efficacy. (a) To determine if mean serum zinc levels differ between acne patients and controls and (b) to determine the efficacy of zinc preparations in the treatment of acne. A systematic review and meta-analysis was performed according to recommended PRISMA [Preferred Reporting Items for Systematic Reviews and Meta-Analyses] guidelines. Subjects with acne had significantly lower serum zinc levels compared to controls. Patients who were treated with zinc had a significant improvement in mean inflammatory papule count compared to those who were not treated with zinc. There was no significant difference in the incidence of side effects in zinc supplementation vs comparators. Acne patients have decreased serum zinc levels. Zinc is effective for the treatment of acne, particularly at decreasing the number of inflammatory papules, when used as monotherapy or as an adjunctive treatment.

Topical benzoyl peroxide for acne

BACKGROUND

Acne is a common, economically burdensome condition that can cause psychological harm and, potentially, scarring. Topical benzoyl peroxide (BPO) is a widely used acne treatment; however, its efficacy and safety have not been clearly evaluated.

OBJECTIVES

To assess the effects of BPO for acne.

SEARCH METHODS

We searched the following databases up to February 2019: the Cochrane Skin Specialised Register, CENTRAL, MEDLINE, Embase, and LILACS. We also searched five trials registers and checked the reference lists of relevant randomised controlled trials (RCTs) and systematic reviews.

SELECTION CRITERIA

We included RCTs that compared topical BPO used alone (including different formulations and concentrations of BPO) or as part of combination treatment against placebo, no treatment, or other active topical medications for clinically diagnosed acne (used alone or in combination with other topical drugs not containing BPO) on the face or trunk.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as expected by Cochrane. Primary outcome measures were 'participant global self-assessment of acne improvement' and 'withdrawal due to adverse events in the whole course of a trial'. 'Percentage of participants experiencing any adverse event in the whole course of a trial' was a key secondary outcome.

MAIN RESULTS

We included 120 trials (29,592 participants randomised in 116 trials; in four trials the number of randomised participants was unclear). Ninety-one studies included males and females. When reported, 72 trials included participants with mild to moderate acne, 26 included participants with severe acne, and the mean age of participants ranged from 18 to 30 years. Our included trials assessed BPO as monotherapy, as add-on treatment, or combined with other active treatments, as well as BPO of different concentrations and BPO delivered through different vehicles. Comparators included different concentrations or formulations of BPO, placebo, no treatment, or other active treatments given alone or combined. Treatment duration in 80 trials was longer than eight weeks and was only up to 12 weeks in 108 trials. Industry funded 50 trials; 63 trials did not report funding. We commonly found high or unclear risk of performance, detection, or attrition bias. Trial setting was under-reported but included hospitals, medical centres/departments, clinics, general practices, and student health centres. We reported on outcomes assessed at the end of treatment, and we classified treatment periods as short-term (two to four weeks), medium-term (five to eight weeks), or long-term (longer than eight weeks). For 'participant-reported acne improvement', BPO may be more effective than placebo or no treatment (risk ratio (RR) 1.27, 95% confidence interval (CI) 1.12 to 1.45; 3 RCTs; 2234 participants; treatment for 10 to 12 weeks; low-certainty evidence). Based on low-certainty evidence, there may be little to no difference between BPO and adapalene (RR 0.99, 95% CI 0.90 to 1.10; 5 RCTs; 1472 participants; treatment for 11 to 12 weeks) or between BPO and clindamycin (RR 0.95, 95% CI 0.68 to 1.34; 1 RCT; 240 participants; treatment for 10 weeks) (outcome not reported for BPO versus erythromycin or salicylic acid). For 'withdrawal due to adverse effects', risk of treatment discontinuation may be higher with BPO compared with placebo or no treatment (RR 2.13, 95% CI 1.55 to 2.93; 24 RCTs; 13,744 participants; treatment for 10 to 12 weeks; low-certainty evidence); the most common causes of withdrawal were erythema, pruritus, and skin burning. Only very low-certainty evidence was available for the following comparisons: BPO versus adapalene (RR 1.85, 95% CI 0.94 to 3.64; 11 RCTs; 3295 participants; treatment for 11 to 24 weeks; causes of withdrawal not clear), BPO versus clindamycin (RR 1.93, 95% CI 0.90 to 4.11; 8 RCTs; 3330 participants; treatment for 10 to 12 weeks; causes of withdrawal included local hypersensitivity, pruritus, erythema, face oedema, rash, and skin burning), erythromycin (RR 1.00, 95% CI 0.07 to 15.26; 1 RCT; 60 participants; treatment for 8 weeks; withdrawal due to dermatitis), and salicylic acid (no participants had adverse event-related withdrawal; 1 RCT; 59 participants; treatment for 12 weeks). There may be little to no difference between these groups in terms of withdrawal; however, we are unsure of the results because the evidence is of very low certainty. For 'proportion of participants experiencing any adverse event', very low-certainty evidence leaves us uncertain about whether BPO increased adverse events when compared with placebo or no treatment (RR 1.40, 95% CI 1.15 to 1.70; 21 RCTs; 11,028 participants; treatment for 10 to 12 weeks), with adapalene (RR 0.71, 95% CI 0.50 to 1.00; 7 RCTs; 2120 participants; treatment for 11 to 24 weeks), with erythromycin (no participants reported any adverse events; 1 RCT; 89 participants; treatment for 10 weeks), or with salicylic acid (RR 4.77, 95% CI 0.24 to 93.67; 1 RCT; 41 participants; treatment for 6 weeks). Moderate-certainty evidence shows that the risk of adverse events may be increased for BPO versus clindamycin (RR 1.24, 95% CI 0.97 to 1.58; 6 RCTs; 3018 participants; treatment for 10 to 12 weeks); however, the 95% CI indicates that BPO might make little to no difference. Most reported adverse events were mild to moderate, and local dryness, irritation, dermatitis, erythema, application site pain, and pruritus were the most common.

AUTHORS' CONCLUSIONS

Current evidence suggests that BPO as monotherapy or add-on treatment may be more effective than placebo or no treatment for improving acne, and there may be little to no difference between BPO and either adapalene or clindamycin. Our key efficacy evidence is based on participant self-assessment; trials of BPO versus erythromycin or salicylic acid did not report this outcome. For adverse effects, the evidence is very uncertain regarding BPO compared with adapalene, erythromycin, or salicylic acid. However, risk of treatment discontinuation may be higher with BPO compared with placebo or no treatment. Withdrawal may be linked to tolerability rather than to safety. Risk of mild to moderate adverse events may be higher with BPO compared with clindamycin. Further trials should assess the comparative effects of different preparations or concentrations of BPO and combination BPO versus monotherapy. These trials should fully assess and report adverse effects and patient-reported outcomes measured on a standardised scale.

The role of zinc in the treatment of acne: A review of the literature

Acne vulgaris is a chronic disease of the pilosebaceous units presenting as inflammatory or noninflammatory lesions in individuals of all ages. The current standard of treatment includes topical formulations in the forms of washes, gels, lotions, and creams such as antibiotics, antibacterial agents, retinoids, and comedolytics. Additionally, systemic treatments are available for more severe or resistant forms of acne. Nevertheless, these treatments have shown to induce a wide array of adverse effects, including dryness, peeling, erythema, and even fetal defects and embolic events. Zinc is a promising alternative to other acne treatments owing to its low cost, efficacy, and lack of systemic side effects. In this literature review, we evaluate the effectiveness and side-effect profiles of various formulations of zinc used to treat acne.

Effect of zinc oxide on the rheological and mucoadhesive properties of poloxamer 407-based mucoadhesive thermosensitive gel

BACKGROUND

To improve the therapeutic efficacy of drugs for hemorrhoid, mucoadhesive thermosensitive gel (MTG) system was developed.

METHODS

The MTG was prepared using poloxamer 407 (P407, 13% and 14%), polycarbophil (PC, 0.2% w/v), phenylephrine hydrochloride (0.25% w/v), lidocaine hydrochloride (1.88% w/v), and prednisolone acetate (0.05% w/v). Then, zinc oxide (ZnO) was added as an astringent as well as mucoadhesiveness-enhancing agent. Two kinds of poloxamer-based MTGs were compared in aspects of rheology, mucoadhesiveness, syringeability, and in vitro release study.

RESULTS

Both the two MTGs (13% and 14% P407) showed Newtonian behavior at 20°C whereas pseudoplastic flow at 37°C. The addition of ZnO into MTGs enhanced the mucoadhesiveness and syringeability and led the drug components to be released in accordance with Fickian mechanism.

CONCLUSIONS

Taken together, the MTG-containing ZnO can be a more effective and convenient delivery system for the treatment of hemorrhoid with a reduced dosage interval.