Current concepts: topical therapy for acne

5: Final Report on the Safety Assessment of 2-Methylresorcinol and Resorcinol

2-Methylresorcinol and Resorcinol are most frequently used in cosmetic hair dye formulations at concentrations between 1 and 5%. The results of cutaneous and oral feeding studies have indicated that both 2-Methylresorcinol and resorcinol are readily absorbed by rodents and are rapidly eliminated. Acute oral toxicity studies indicate that 2-Methylresorcinol is moderately toxic and Resorcinol is slightly to moderately toxic. Subchronic feeding and dermal studies of bothingredients produced no significant effects. A chronic dermal study was uneventful. Significant skin effects were observed in mice, but not in rabbits, following dermal application of Resorcinol at 5%. A 10% Resorcinol solution was not irritating to guinea pigs. A 2.5% 2-Methylresorcinol solution was classified as a primary irritant in rabbits, but 10% 2-Methylresorcinol was not irritating to guinea pigs. 2-Methylresorcinol was not an ocular irritant at 2.5%, but irritation was produced at 5% concentration in unwashed rabbit eyes. Neither 2-Methylresorcinol at 5% nor Resorcinol at 3% produced sensitization in guinea pigs. 2-Methylresorcinol was not photoallergenic to guinea pigs but was a sensitizer at 10%. Resorcinol was not photoallergenic to guinea pigs but was a sensitizer at 10%. Resorcinol and 2-Methylresorcinol were nonmutagenic in microbial and tissue culture assays for mutagenicity. Topically applied hair dyes containing 2-Methylresorcinol and Resorcinol were negative for carcinogenicity. Resorcinol showed no cocarcinogenic potential when tested on mice and rats. 2-Methylresorcinol at 3% concentration produced no evidence of irritation or sensitization in human subjects. Resorcinol was a mild skin irritant and rare sensitizer in clinical testing, but not when tested on nonclinical groups. On the basis of the available animal and clinical data, it is concluded that 2-Methylresorcinol and Resorcinol are safe as cosmeticingredients in the present practices of use and concentrations.

Correlation between the severity and type of acne lesions with serum zinc levels in patients with acne vulgaris

Acne vulgaris is the most common cutaneous disorder affecting adolescents and young adults. Some studies have reported an association between serum zinc levels and acne vulgaris. We aimed to evaluate the serum zinc level in patients with acne vulgaris and compare it with healthy controls. One hundred patients with acne vulgaris and 100 healthy controls were referred to our clinic. Acne severity was classified according to Global Acne Grading System (GAGS). Atomic absorption spectrophotometry was used to measure serum zinc levels. Mean serum level of zinc in acne patients and controls was 81.31 ± 17.63 μg/dl and 82.63 ± 17.49 μg/dl, respectively. Although the mean serum zinc level was lower in acne group, it was not statistically significant (P = 0.598). There was a correlation between serum zinc levels with severity and type of acne lesions. The results of our study suggest that zinc levels may be related to the severity and type of acne lesions in patients with acne vulgaris. Relative decrease of serum zinc level in acne patients suggests a role for zinc in the pathogenesis of acne vulgaris.

Skin tolerability and efficacy of combination therapy with hydrogen peroxide stabilized cream and adapalene gel in comparison with benzoyl peroxide cream and adapalene gel in common acne. A randomized, investigator-masked, controlled trial

BACKGROUND

Combination therapy with antiseptics such as benzoyl peroxide (BP) and topical retinoids is widely used as first-line treatment for acne vulgaris (AV). However, these combinations could have a suboptimal skin tolerability. Recently, a new formulation of hydrogen peroxide (HP) 1% in stabilized cream (Crystacide; Mipharm, Milan, Italy) became available. A previous clinical study has shown that HP cream monotherapy presents a better skin tolerability in comparison with BP in patients with mild AV.

OBJECTIVES

To evaluate the tolerability and the efficacy of combination therapy with HP cream and adapalene 0.1% gel in comparison with the combination of BP 4% cream and adapalene 0.1% gel in the treatment of mild to moderate AV.

METHODS

In a randomized, investigator-blinded trial, 52 patients (mean +/- SD age 25 +/- 6 years; 19 men and 33 women) with AV were randomly assigned to HP cream and adapalene gel (group HP + A) or to BP cream and adapalene gel (group BP + A), for eight consecutive weeks. Efficacy was assessed by total (TL), inflammatory (IL) and noninflammatory (NL) lesion counts performed at baseline and weeks 4 and 8. Tolerability was assessed by evaluating skin erythema, burning and dryness at weeks 4 and 8.

RESULTS

All patients completed the study. At baseline, the mean +/- SD numbers of TL, IL and NL were 44 +/- 9, 25 +/- 7 and 19 +/- 6 in group HP + A and 40 +/- 9, 21 +/- 7 and 19 +/- 9 in group BP + A, respectively. At the end of the treatment period, TL, IL and NL were reduced by 93%, 92% and 95%, respectively, in group HP + A and by 88%, 86% and 90%, respectively, in group BP + A. A significantly (P = 0.0025) greater reduction in NL was observed in group HP + A in comparison with group BP + A. Tolerability was significantly better in group HP + A in comparison with group BP + A (P = 0.02). Skin dryness and burning sensation were more frequent in group BP + A.

CONCLUSIONS

The combination of adapalene and HP cream is an effective topical treatment regimen in mild to moderate AV. This combination has shown a better tolerability profile in comparison with the combination of BP and adapalene.

A new method for quality control of zinc pyritione pharmaceutical and cosmetic forms

A simple high-performance liquid chromatographic (HPLC) method was developed to determine zinc pyritione in pharmaceutical and cosmetic products. Reversed-phase chromatography was conducted using a C18 column with an isocratic mobile phase consisting of a suitable mixture of methanol, acetonitrile, and water (30:2.5:20). The effluent was monitored on a ultraviolet (UV) detector at 243 nm. The method was validated following International Conference on Harmonisation (ICH) suggestions and proved accurate, precise, and specific.

Comparative efficacy of four Ayurvedic formulations in the treatment of acne vulgaris: a double-blind randomised placebo-controlled clinical evaluation

Eighty-two patients with acne vulgaris were randomised into five groups. Four different Ayurvedic treatment schedules were given orally for 6 weeks, while one group received a placebo. Physical and clinical investigations were carried out at 2 week intervals. A significant reduction in lesion count was observed in patients receiving Sunder Vati when compared with the placebo and the other Ayurvedic formulations, which failed to produce any significant difference from the pretreatment condition. The drug therapies were well tolerated.

How I Manage Acne in Athletes

In brief: Athletes aggravate acne by coming in contact with other competitors, rubbing against sports equipment and tight clothing, and sweating excessively. Another factor is the psychological stress involved in competition. However, these aggravations are part of sports, so it is impossible to avoid them. Athletes should wear clean, dry, loose-fitting, absorbent, cotton clothing and change wet clothing as soon as possible. They should work out with minimal clothing and equipment in a cool, well-ventilated environment whenever practical. Systemic and topical antimicrobial drugs are the most effective, dependable form of acne treatment, although some side effects exist. If these drugs do not control a patient's acne, he or she should be referred to a dermatologist.

Systemic absorption of clindamycin hydrochloride after topical application

Clindamycin has become a highly popular drug for the topical therapy of acne; however, the extent to which it is systemically absorbed from the skin has has not been established. We measured the serum level and urinary excretion of clindamycin on the third day and the twenty-seventh day of therapy in thirteen patients who were applying 1% clindamycin hydrochloride topically for acne. There was no detectable antibiotic in the serum of any subject (less than 0.4 microgram/ml); in contrast, clindamycin was found in the urine of ten of the thirteen patients. There was marked intersubject variation in the urinary excretion of the drug, ranging from less than 10 to 500 micrograms/day. However, there was a highly significant correlation (p less than 0.0001) for a given subject between excretion values on days 3 and 27. There was no correlation between urinary excretion of clindamycin and either racial pigmentation or severity of acne in this relatively small group of patients. After topical application of 1% clindamycin hydrochloride, an average of 4% to 5% of clindamycin appears to be absorbed systemically, but greater amounts are absorbed in some individuals.