Allergic contact dermatitis in a girl due to several cosmetics containing diazolidinyl-urea or imidazolidinyl-urea

Moisturizer induced contact anaphylaxis

BACKGROUND

Contact allergens typically trigger localised reactions, but systemic Type I hypersensitivity from skin contact reactions are rare.

CASE PRESENTATION

We present the case of a 69-year-old non-atopic male who developed anaphylaxis following the application of moisturizer to an area of chemical burns. Skin testing showed a strong positive result to moisturizer. Whilst not all ingredients were available for testing, phenoxyethanol was thought to be the likely culprit agent based on literature review and a weakly positive skin test result.

CONCLUSION

Products such as moisturizers can rarely trigger anaphylaxis, especially when applied to damaged skin which may favor systemic absorption. This case highlights the need for careful consideration of cosmetic application when discerning culprit allergens.

Imidazolidinyl Urea

The Expert Panel for Cosmetic Ingredient Safety reviewed updated information that has become available since their original assessment from 1980, along with updated information regarding product types, and frequency and concentrations of use, and reaffirmed their original conclusion that Imidazolidinyl Urea is safe as a cosmetic ingredient in the practices of use and concentration as described in this report.

Effect of Commonly Used Cosmetic Preservatives on Healthy Human Skin Cells

Cosmetic products contain preservatives to prevent microbial growth. The various types of preservatives present in skincare products applied on the skin induce many side effects. We tested several types of preservatives such as phenoxyethanol, methyl paraben, propyl paraben, imidazolidinyl urea (IU), the composition of gluconolactone and sodium benzoate (GSB), diazolidinyl urea (DU), and two grapefruit essential oils, one of which was industrially produced and a second which was freshly distilled from fresh grapefruit peels. This study aimed to find the relationship between preservative concentration, cell growth, collagen secretion, and cell viability. We hypothesized that these products induced a decrease in collagen secretion from human dermal fibroblasts. Our research, for the first time, addressed the overall effect of other preservatives on skin extracellular matrix (ECM) by studying their effect on metalloproteinase-2 (MMP-2) activity. Except for cytotoxicity and contact sensitivity tests, there are no studies of their effect on skin ECM in the available literature. These studies show potential antimicrobial activity, especially from the compounds IU and DU towards reference bacteria and the compounds methyl paraben and propyl paraben against reference fungi. The MTS test showed that fibroblasts are more sensitive to the tested group of preservatives than keratinocytes, which could be caused by the differences between the cells' structures. The grapefruit oils exhibited the most cytotoxicity to both tested cell lines compared to all considered preservatives. The most destructive influence of preservatives on collagen synthesis was observed in the case of IU and DU. In this case, the homemade grapefruit oil turned out to be the mildest one. The results from a diverse group of preservatives show that whether they are natural or synthesized compounds, they require controlled use. Appropriate dosages and evaluation of preservative efficacy should not be the only aspects considered. The complex effect of preservatives on skin processes and cytotoxicity is an important topic for modern people.

Simultaneous HPLC Determination of Clindamycin Phosphate, Tretinoin, and Preservatives in Gel Dosage Form Using a Novel Stability-Indicating Method

The most well-known, effective medicines for acne therapy are clindamycin phosphate and tretinoin. For the first time, we have developed and validated a reversed-phase HPLC stability-indicating technique for the detection of clindamycin phosphate (CLP), tretinoin (TRN), and two preservatives, methylparaben (MP) and imidazolidinyl urea (IU), simultaneously in this work. Most of the chromatographic conditions in the present study were optimized to achieve better separation. The best separation results were obtained using gradient elution on a C-18 (250 × 4.6 mm), 5 µm column, with a mobile phase consisting of solution A (1 mL/L ortho-phosphoric acid in water) and solution B (methanol), at a flow rate of 1.0 mL/min, with UV detection at wavelengths of 200 nm and 353 nm. Standard parameters such as system suitability, precision, accuracy, specificity, robustness, linearity, range, detection limit, quantification limit, and reagent stability were used to validate the developed technique. According to the standards of the International Council for Harmonization, all of the experimental parameters were found to be within allowable bounds (ICH). The simultaneous concentrations of clindamycin phosphate, tretinoin, methylparaben, and imidazolidinyl urea in pharmaceutical formulations were successfully determined using the suggested approach. The proposed RP-HPLC method detected no interfering peaks in the chromatogram. We may conclude from the data that the new RP-HPLC method can be utilized in pharmaceutical laboratories to simultaneously assess clindamycin phosphate, tretinoin, and two preservatives, methylparaben and imidazolidinyl urea, for both qualitative and quantitative analyses.

Skin Barrier Enhancing Alternative Preservation Strategy of O/W Emulsions by Water Activity Reduction with Natural Multifunctional Ingredients

Water activity (aw) as an important parameter for self-preservation can help to control microbial growth in cosmetic formulations. However, high amounts of water-binding substances are required to lower the aw enough to affect microbial growth. Since consequences for the skin barrier have been poorly studied so far, we investigated the effect of aw-lowering agents on both the antimicrobial properties of o/w emulsions and skin physiological parameters. A combination of selected natural humectants (Sodium lactate, Propanediol, Erythritol, Betaine and Sodium PCA) with a total concentration of 28 wt% in an o/w emulsion was able to reduce its aw from 0.980 ± 0.003 to 0.865 ± 0.005. The challenge test results of the aw-lowered emulsion showed a convincing microbial count reduction in potentially pathogenic microorganisms. The addition of as little as 0.5% of the antimicrobial multifunctionals Glyceryl Caprylate and Magnolia Officinalis Bark Extract further enhanced the antimicrobial effect, resulting in adequate antimicrobial protection. Moreover, twice-daily application of the aw-lowered emulsion for a period of four weeks led to a skin barrier-enhancing effect: TEWL significantly decreased, and SC hydration significantly increased. Thus, we present an opportunity to replace conventional preservatives with a natural alternative preservation strategy that has been shown to offer benefits for the skin.

Percutaneous permeability of 1-phenoxy-2-propanol, a preservative in cosmetics

1-Phenoxy-2-propanol (PP) is used as a preservative in cosmetics. PP is currently permitted to be used to up to 1% in cosmetic formulations in Korea and Europe. For risk assessment, percutaneous absorption is a crucial factor, but dermal absorption of PP has not yet been reported. In this study, Franz diffusion method was used to determine the percutaneous penetration of PP using the dorsal skin of rats. Each formulation of shampoo or cream, 113.6 mg/cm², was applied to a donor compartment of Franz diffusion cell for 24 h. Receptor fluid was collected at 0, 1, 2, 4, 8, 12, and 24 h following dermal application. Remaining formulation was removed with a cotton swab after last sampling. Using tape stripping method, stratum corneum was removed. PP in epidermis and dermis was extracted in PBS for 24 h. The concentration of PP from the swab, stratum corneum, and epidermis and dermis samples was determined using high performance liquid chromatography. Total percutaneous absorption rates of PP for shampoo and cream were 50.0 ± 6.0% and 33.0 ± 3.2%, respectively. In vitro skin permeability was calculated as 1,377.2 ± 240.1 mg/cm² for shampoo and 1,038.0 ± 72.2 mg/cm² for cream for 24 h.

Hydrogel allergic contact dermatitis and imidazolidinyl urea/diazolidinyl urea

Hydrogels contain modified carboxymethylcellulose polymer together with propylene glycol as known components. Nowadays, they are common agents used in the treatment of leg ulcer patients, and a possible cause of allergic contact dermatitis. However in the published data, not all the patients with positive patch tests to hydrogels were sensitized to propylene glycol, remaining some allergens to be identified. The authors describe two leg ulcer patients sensitized for different commercial available hydrogels tested "as is", with concomitant patch tested positivity to imidazolidinyl urea (IU) and diazolidinyl urea (DU). Patient A was an 84-year-old male, and patient B was a 77-year-old female, both with a known history of leg ulcer for more than 8 weeks. Patient A was sensitized for Intrasite Gel(®), Hydrogel Nu-Gel(®), Askina Gel(®), neomycin and budesonide. Patient B was sensitized for Intrasite Gel(®), Hydrogel Nu-Gel(®), Askina Gel(®), Hydrosorb Gel(®), Fragance mix 1 and 2, Amerchol, geraniol and citral. They were negative to propylene glycol tested in 5% pet. and 20% aq. IU and DU are formaldehyde-releasing agents, used as antimicrobial preservatives in the formulation of pharmaceutical creams and ointments and are known to cause contact dermatitis. Also, in many studies performed, it has been shown that contact allergy is high in patients with leg ulcers. As result, assessment of the relevance of positive patch test reactions in these patients can be difficult. Although we were not able to get the complete ingredient list of the hydrogels tested, attending to these observations, could be of importance to evaluate the presence of IU/DU in patients with suspected contact dermatitis to hydrogels.