The different decomposition properties of diazolidinyl urea in cosmetics and patch test materials

NIS-Promoted Selective Amino-Diazidation and Amino-Iodoazidation of O-Homoallyl Benzimidates: Synthesis of Vicinal Diazido 1,3-Oxazines and Vicinal Iodoazido 1,3-Oxazines

Amines, especially those with multi-nitrogen moieties, are widespread in natural products and biologically active compounds. Thus, the development of direct and efficient methods to introduce multiple nitrogen-containing fragments into compounds in one step is highly desirable yet challenging. Herein, we report an NIS-promoted selective amino-diazidation and amino-iodoazidation of O-homoallyl benzimidates with NaN₃. By using this protocol, a variety of vicinal diazido-substituted 1,3-oxazines and vicinal iodoazido-substituted 1,3-oxazines were directly synthesized in a controllable manner. Preliminary mechanistic investigations revealed that the reaction operates through a NIS-promoted four-step cascade process. The developed method has the merits of metal-free, excellent functional group compatibility, simple operation, and mild conditions.

Contact allergy to and allergic contact dermatitis from formaldehyde and -releasers: A clinical review and update

This review aims to provide a clinically useful update regarding the role of formaldehyde (FA) and its five main releasers (FRs) quaternium-15, diazolidinyl urea, DMDM hydantoin, imidazolidinyl urea and 2-bromo-2-nitropropane-1,3-diol (bronopol) in contact allergy and allergic contact dermatitis. These ubiquitous preservatives are still often, and sometimes undeclared, present in cosmetics, pharmaceuticals, medical devices, household detergents and chemical (industrial) products. In Europe, the use of free FA and quaternium-15 in cosmetics is forbidden and contact allergy rates have been found to be stable to decreasing. However, FA/FRs still readily provoke localized (e.g., facial/hand), airborne and generalized dermatitis, and may also complicate atopic and stasis dermatitis, or result in nummular dermatitis. Seborrheic-, rosacea- and impetigo-like dermatitis have recently been reported. For a correct diagnosis, FA 2% aq. (0.60 mg/cm² ) should be used, and particularly the FRs bronopol 0.5% pet. and diazolidinyl urea 2% should be patch tested separately in a baseline series. If sensitization to FA occurs, both FA and FRs should preferably be avoided, except perhaps for bronopol in case it tests negatively. If a patient reacts to one or more FRs (such as bronopol, or diazolidinyl/imidazolidinyl urea), but not to FA, then the specific FR(s) should be avoided. This article is protected by copyright. All rights reserved.

The development of dual-function solid-phase method as extraction and a decomposition reaction media for the determination of a formaldehyde releaser, imidazolidinyl urea, in cosmetics

In this study, we present a simple method to determine imidazolidinyl urea (IU) in cosmetics using a solid phase as both a decomposition field and an extraction phase. IU is difficult to quantify because it is a mixture of allantoin-formaldehyde condensation products that are easily decomposed to release formaldehyde. In our method, IU is decomposed to allantoin and 1-[4-(hydroxymethyl)-2,5-dioxoimidazolidin-4-yl]urea (4-HU) on an aminopropyl-bonded silica solid phase. Subsequent high-performance liquid chromatography enables quantification of the resulting allantoin and 4-HU. The quantified value was converted to the total allantoin amount on the basis of molecular weight, and the calculated value was compared with that of an IU reference standard to determine the contents. The calibration curves of the decomposed IU as allantoin and 4-HU were both linear over an IU solution concentration range from 0.05 to 0.65% (w/v). The recoveries from lotion, body soap, and conditioners, which contained 0.1%, 0.3%, and 0.6% (w/w) of IU, respectively, ranged from 88.2 to 107.5%. The relative standard deviation values for the recovery tests of six replicates ranged from 1.03 to 6.97%. The intra-laboratory precisions for the lotion and conditioner A containing 0.3% IU were 3.02 and 4.94%, respectively. This method was well validated and would be helpful in determining IU in cosmetic samples.

Formaldehyde 2% is not a useful means of detecting allergy to formaldehyde releasers- results of the ESSCA network, 2015-2018

BACKGROUND

Studies suggest that patch testing with formaldehyde releasers (FRs) gives significant additional information to formaldehyde 1% aq. and should be considered for addition to the European baseline series (EBS). It is not known if this is also true for formaldehyde 2% aq.

OBJECTIVES

To determine the frequency of sensitization to formaldehyde 2% aq. and co-reactivity with FRs. To establish whether there is justification for including FRs in the EBS.

MATERIALS AND METHODS

A 4-year, multi-center retrospective analysis of patients with positive patch test reactions to formaldehyde 2% aq. and five FRs.

RESULTS

A maximum of 15 067 patients were tested to formaldehyde 2% aq. and at least one FR. The percentage of isolated reactions to FR, without co-reactivity to, formaldehyde 2% aq. for each FR were: 46.8% for quarternium-15 1% pet.; 67.4% imidazolidinyl urea 2% pet.; 64% diazolidinyl urea 2% pet.; 83.3% 1,3-dimethylol-5, 5-dimethyl hydantoin (DMDM) hydantoin 2% pet. and 96.3% 2-bromo-2-nitropropane-1,3-diol 0.5% pet. This demonstrates that co-reactivity varies between FRs and formaldehyde, from being virtually non-existent in 2-bromo-2-nitropropane-1,3-diol 0.5% pet. (Cohen's kappa: 0, 95% confidence interval [CI] -0.02 to 0.02)], to only weak concordance for quaternium-15 [Cohen's kappa: 0.22, 95%CI 0.16 to 0.28)], where Cohen's kappa value of 1 would indicate full concordance.

CONCLUSIONS

Formaldehyde 2% aq. is an inadequate screen for contact allergy to the formaldehyde releasers, which should be considered for inclusion in any series dependant on the frequency of reactions to and relevance of each individual allergen.

Undeclared formaldehyde levels in patient consumer products: formaldehyde test kit utility

PURPOSE

Formaldehyde allergic contact dermatitis (ACD) may be due to products with free formaldehyde or formaldehyde-releasing agents; however, assessment of formaldehyde levels in such products is infrequently conducted. The present study quantifies total releasable formaldehyde from "in-use" products associated with formaldehyde ACD and tests the utility of commercially available formaldehyde spot test kits.

MATERIALS AND METHODS

Personal care products from 2 patients with ACD to formaldehyde were initially screened at the clinic for formaldehyde using a formaldehyde spot test kit. Formaldehyde positive products were sent to the laboratory for confirmation by gas chromatography-mass spectrometry. In addition, 4 formaldehyde spot test kits were evaluated for potential utility in a clinical setting.

RESULTS

Nine of the 10 formaldehyde spot test kit positive products obtained from formaldehyde allergic patients had formaldehyde with total releasable formaldehyde levels ranging from 5.4 to 269.4 µg/g. Of these, only two shampoos tested listed a formaldehyde-releasing agent in the ingredients or product literature. Subsequently, commercially available formaldehyde spot test kits were evaluated in the laboratory for ability to identify formaldehyde in personal care products.

CONCLUSIONS

Chemical based formaldehyde spot test were more reliable than the enzymatic based test in identifying product releasable formaldehyde content. It is concluded that product labeled ingredient lists and available information are often inadequate to confirm the potential for formaldehyde exposure and chemical based spot test kits may have utility for identification of potential formaldehyde exposure from personal care products.