Preservatives In Cosmetic Products Research Articles

Antimicrobial Compounds from Food Waste in Cosmetics

The cosmetics industry has experienced rapid growth, driven by consumer demand for products in line with modern lifestyles and technological advances, with greater awareness of the impacts on health and the ecosystem. This review explores the potential use of antibacterial compounds derived from food waste as sustainable alternatives to synthetic preservatives in cosmetic products. Waste obtained from food, including fruit peels, seeds, and plant remnants, is rich in natural bioactives, including polyphenolic compounds and essential oils that exhibit antimicrobial, antioxidant, anti-inflammatory, and soothing features. The integration of these natural ingredients not only improves the shelf-life and safety of cosmetics but also promotes environmentally friendly practices. We discuss the sources and antimicrobial efficacy of these compounds, along with recent technological innovations. This sustainable approach responds to consumer preferences for natural ingredients, reduces food waste, and supports environmental sustainability, ultimately increasing the value and attractiveness of cosmetic products.

Tannic acid and Gallic Acid as Alternative Compounds for the Application as Preservatives in Cosmetic Products

Tannic acid and Gallic Acid as Alternative Compounds for the Application as Preservatives in Cosmetic Products

Current frequency of contact allergy to isothiazolinones (methyl-, benz- and octylisothiazolinone) across Europe.

The use of methylisothiazolinone (MI) as a preservative in cosmetic products caused an alarming increase in MI contact allergy across Europe in the 2010s. This was followed by regulations of use with a total ban on leave-on (implemented in 2017) and reduced use concentrations in rinse-off cosmetics (2018). To follow-up on the prevalence of contact allergy to MI and the related benzisothiazolinone (BIT) and octylisothiazolinone (OIT) in consecutively patch-tested patients in Europe. A cross-sectional audit following the design of two previous audits on MI contact allergy from 1 May 2022 to 31 October 2022 included all patients patch tested with the European baseline series, including or supplemented with MI, BIT and OIT across 10 departments in eight European countries. A total of 2554 patients were consecutively patch tested with the three isothiazolinones during the study period. The prevalence of MI and BIT contact allergy was 2.9% (95% confidence interval [CI]: 2.3%-3.7%; range 1.1%-5.8%) and 3.1% (95% CI: 2.4%-3.9%; range 0.0%-6.6%), respectively; that of OIT was 0.7% (95% CI: 0.4%-1.1%; range 0%-3.2%). Rinse-off cosmetic (73.3%) and leave-on cosmetic products (13.3%) were still associated with eliciting allergic contact dermatitis to MI. We confirmed a positive impact of regulatory measures on the prevalence of MI contact allergy in Europe, which halved compared to 2015. However, our data suggest that consumers may still be exposed to older cosmetic products containing MI. BIT has superseded MI in causing contact allergy, despite not being allowed for use in cosmetic products.

Exopolysaccharides Synthesized by Lacticaseibacillus rhamnosus ŁOCK 0943: Structural Characteristics and Evaluation of Biological and Technological Properties

Lactic acid bacteria can synthesize extracellular exopolysaccharides (EPSs) that have versatile physicochemical and biological properties. In this paper, the EPSs synthesized by Lacticaseibacillus rhamnosus ŁOCK 0943 were characterized. Their structure, biological, and technological activity, as well as application potential, were analyzed. Chemical analysis showed that this strain produces mannan and β-1,6-glucan. Their emulsifying, antagonistic, and antioxidant properties, along with their prebiotic potential, were assessed. The analysis of the tested polymers’ ability to create a stable emulsion showed that their emulsifying activity depends mainly on the type of oily substance used. The analysis of the antagonistic activity revealed that these EPSs can inhibit the growth of yeasts (e.g., Candida albicans ATCC 10231) and potentially pathogenic bacteria (e.g., Clostridium acetobutylicum ŁOCK 0831, Enterococcus faecalis ATCC 29212). Moreover, EPSs positively influenced the growth of all tested probiotic bacteria. Furthermore, EPSs can be successfully used as a preservative in cosmetic products. The most effective results were obtained with the use of a 0.05% solution of a chemical preservative (bronopol) and 0.25 mg/mL of the EPSs.

Are Phenoxyethanol products safe for babies? – A review of current evidences

Phenoxyethanol is used at concentrations below 1% as a preservative in cosmetic products and fixative in perfumes. Some people have reported adverse responses to phenoxyethanol on their skin. Some suggest that the test subjects' negative reactions are the result of allergies. Nevertheless, there are claims that it's simply a skin irritant that has varying degrees of effect on various people. In 2012, the ANSM (French National Agency of Medicine and Health Products Safety) advised against using Phenoxyethanol in cosmetics for babies' bottoms. On a European level, this advice had not been confirmed. The purpose of this article is to discuss the potential negative effects of phenoxyethanol on newborns and infants.

Synthesis of Natural Salicylic Acid as a Cosmetic Ingredient Using Green Chemistry Methods

Objective: Salicylic acid (SA) is a keratinolytic agent also used as preservative in cosmetic products. Green chemistry, known as sustainable chemistry, is the design of products and processes eliminating the use of chemicals. It is applicable throughout a chemical product's life cycle, including its design, manufacture, use, and final disposal. The aim of this study was to synthesize SA with green chemistry methods using different amounts of wintergreen oil and to optimize the relevant steps in this path. Materials and Methods: The SA was synthesized from natural wintergreen oil using green chemistry methods. First laboratory-scale synthesis was developed and 15 laboratory-scale synthesis trial patterns, using reaction temperature, wintergreen oil-sodium hydroxide molar ratio, sodium hydroxide-water weight ratio, reaction time and pH were performed. Purity was analysed with gas chromatographymass spectrometry (GC-MS) and moisture analysis was performed. Results and Conclusion: As a result of pilot production run with 1 kg, 5 kg, and three batches of 20 kg of wintergreen oil, SA was produced with a yield range of 91.06-93.92 %. The resulting SA batches had a purity of approximately 99%. This is a sufficient degree of purity for SA to be used as a raw material in cosmetics products. Filtering the SA solution using a filter press reduced crystal drying time and brought down the total production time to eight days.

Comparative evaluation of carvacrol and eugenol chitosan nanoparticles as eco-friendly preservative agents in cosmetics

The current status of controversy regarding the use of certain preservatives in cosmetic products makes it necessary to seek new ecological alternatives that are free of adverse effects on users. In our study, two different natural terpenes Carvacrol and Eugenol were encapsulated in chitosan nanoparticles in different ratios of Chitosan:terpene. The nanoparticles were characterized by DLS and TEM showing a maximum particle size of 100 nm. The chemical structure, thermal properties, and release profile of terpenes were evaluated showing a successful protection of terpene in Chitosan matrix. Two different release profile were observed showing a faster release profile in the case of Eugenol. Antimicrobial properties of nanoparticles were evaluated against typical microbial contaminants found in cosmetic products, showing higher antimicrobial properties with chitosan encapsulation of terpenes. Furthermore, natural moisturizing cream inoculated with beforementioned microorganisms was formulated with Carvacrol-chitosan nanoparticles and Eugenol-chitosan nanoparticles to evaluate the preservative efficiency, indicating a highest preservative efficiency with the use of Eugenol-chitosan nanoparticles.

Characterization of photoproducts and global ecotoxicity of chlorphenesin: A preservative used in skin care products.

Photolysis experiments of chlorphenesin, used as a preservative in cosmetic products, were performed in aqueous solution and on a cream used in cosmetics. Three by-products resulting from the direct UV-visible photodegradation of chlorphenesin were characterized by chromatography (gas and liquid) coupled with tandem mass spectrometry (GC-MS/MS and LC-HR MS/MS) and found in both solutions. In vitro tests on Vibrio fischeri bacteria showed that the overall ecotoxicity of chlorphenesin increased with increasing irradiation time in both samples. In silico QSAR (Quantitative Structure Activity Relationship) tests were performed using T.E.S.T. (Toxicity Estimation Software Tool). Among the degradation compounds identified, 4-chlorophenol must contribute to the increased ecotoxicity of the photolyzed solution since the in silico LC50 estimated for all tests performed are always lower than those obtained for chlorphenesin.

Thymoquinone-Loaded Chitosan Nanoparticles as Natural Preservative Agent in Cosmetic Products

The current status of controversy regarding the use of certain preservatives in cosmetic products makes it necessary to seek new ecological alternatives that are free of adverse effects on users. In our study, the natural terpene thymoquinone was encapsulated in chitosan nanoparticles. The nanoparticles were characterized by DLS and TEM, showing a particle size of 20 nm. The chemical structure, thermal properties, and release profile of thymoquinone were evaluated and showed a successful stabilization and sustained release of terpenes. The antimicrobial properties of the nanoparticles were evaluated against typical microbial contaminants found in cosmetic products, showing high antimicrobial properties. Furthermore, natural moisturizing cream inoculated with the aforementioned microorganisms was formulated with thymoquinone-chitosan nanoparticles to evaluate the preservative efficiency, indicating its promising use as a preservative in cosmetics.

Formaldehyde analysis of seized cosmetic products by HS-GC-MS of methylal, ethoxymethoxymethane, and ethylal derivatives

Formaldehyde is a carcinogenic compound used as preservative in cosmetic products. In this study, a derivatization procedure using MeOH, EtOH and HCl (25:25:1), and incubation at 60ºC for 4 hours was optimized, and the derivatized products - methylal, ethoxymethoxymethane (EMM), and ethylal - were directly analyzed by headspace-gas chromatography-mass spectrometry (HS-GC-MS) to determine formaldehyde concentrations. The validated method provided good linearity of the standard curve, selectivity, recovery (89.6-106.6%), repeatability, and intermediate precision (RSD < 12%), with an LOD of 0.0015% and an LOQ of 0.005% for all derivatized analytes. The validated method showed to be fast, clean, and easy to implement in a laboratory. To the best of our knowledge, this is the first reported HS-GC-MS procedure to determine formaldehyde as methylal, ethylal, and EMM as derivatized compounds. The method was satisfactorily applied for the analysis of nine hair-straightener cream samples seized by the Civil Police of the Federal District, Brazil. Eight samples contained formaldehyde, at levels ranging from 0.33 to 4.02 %, higher than the legal levels, indicating the need to control the levels of this toxic compound in cosmetic products.

Stricter regulation applies to antimicrobial substances when used as biocides compared to cosmetics under current EU legislation

Antimicrobial substances are substances that have the ability to kill or slow down the growth of microorganisms such as bacteria, algae and fungi. Exposure of microorganisms to low concentrations of antimicrobial substances may lead to the development of antimicrobial resistance. To protect human health and the environment and to limit resistance, the risks for the release of these substances into the environment should be minimized from all sources.Under the current EU legal framework, some specific uses of antimicrobial substances are strictly regulated whereas others are not. When antimicrobial substances are used as active substances in biocidal products, such as disinfectants, they are regulated by Biocidal Products Regulation. When the same substances are used as preservatives in cosmetic products they fall under Cosmetic Products Regulation.In this paper, we investigated how the regulation of antimicrobial substances differ when used in biocidal products compared to cosmetic products. This was achieved by performing a systematic comparison using document analysis with focus on aims, scope, information requirements, and risk assessment procedures for biocidal active substances and cosmetic preservatives. One of the main differences identified is that no environmental data or environmental risk assessment are required for approval of cosmetic preservatives. In contrast, environmental data and risk assessment for both the active substances and one representative product would be required for the approval of the same substance if used as a biocidal active substance. This means first that a substance not approved for use in biocidal products due to its hazardous environmental properties can still be approved as a cosmetic preservative. And second, the environmental release of antimicrobial substances from cosmetic products remains unassessed and uncontrolled, despite the obvious risks of cosmetic ingredients being emitted into the environment via wastewater.From this, we recommend that an environmental risk assessment is added to the requirements for market approval of cosmetic preservatives to achieve the aim of a high level of protection for the environment as set by several EU regulations. This would be in line with the “one substance – one assessment” approach proposed by the European Commission. While the details of “one substance – one assessment” approach are not decided, it is believed to contribute to more coordinated and transparent chemical safety assessments and enhance interlinking between the regulations.

Biogenic Silver Nanoparticles from Iris tuberosa as Potential Preservative in Cosmetic Products.

Biogenic-silver nanoparticles emerge as new nanosilver platforms that allow us to obtain silver nanoparticles via “green chemistry”. In our study, biogenic-silver nanoparticles were obtained from Iris tuberosa leaf extract. Nanoparticles were characterized by a UV-vis spectroscopy, dynamical light scattering technique. The transmission electron microscope revealed spheric and irregular nanoparticles with 5 to 50 nm in diameter. Antimicrobial properties were evaluated against typical microbial contaminants found in cosmetic products, showing high antimicrobial properties. Furthermore, natural moisturizing cream was formulated with biogenic-silver nanoparticles to evaluate the preservative efficiency through a challenge test, indicating its promising use as preservative in cosmetics.

Opinion of the Scientific Committee on Consumer Safety (SCCS) – Final Opinion on propylparaben (CAS No 94-13-3, EC No 202-307-7)

In cosmetic products, the ingredient propylparaben (CAS No 94-13-3, EC No 202-307-7) with the chemical names Propyl 4-hydroxybenzoate and 4-Hydroxybenzoic acid propyl ester is currently regulated as a preservative in a concentration up to 0.14% (as acid) (Annex V/12a). In addition, a safe concentration was established for mixtures of parabens, where the sum of the individual concentrations should not exceed 0.8% (as acid). However, in such mixtures the sum of the individual concentrations of butyl- and propylparaben and their salts should not exceed 0.14%. Propylparaben was subject to different safety evaluations in 2005 (SCCP/0874/05), 2006 (SCCP/1017/06), 2008 (SCCP/1183/08), 2010 (SCCS/1348/10), 2011 (SCCS/1446/11), and in 2013 (SCCS/1514/13). On the basis of the safety assessment of propylparaben, and considering the concerns related to potential endocrine disrupting properties, the SCCS has concluded that propylparaben is safe when used as a preservative in cosmetic products up to a maximum concentration of 0.14%. The available data on propylparaben provide some indications for potential endocrine effects. However, the current level of evidence is not sufficient to regard it as an endocrine disrupting substance, or to derive a toxicological point of departure based on endocrine disrupting properties for use in human health risk assessment. The SCCS mandate does not address environmental aspects. Therefore, this assessment did not cover the safety of propylparaben for the environment. Link to the Opinion (SCCS/1623/20): https://ec.europa.eu/health/sites/default/files/scientific_committees/consumer_safety/docs/sccs_o_243.pdf.

Amended Safety Assessment of Methylchloroisothiazolinone and Methylisothiazolinone as Used in Cosmetics.

The Expert Panel for Cosmetic Ingredient Safety (Panel) reassessed the safety of the mixture Methylchloroisothiazolinone (MCI)/Methylisothiazolinone (MI), which functions as a preservative in cosmetic products. The Panel reviewed relevant animal and human data provided in this safety assessment, and data from the previously published safety assessment of this mixture, and concluded that MCI/MI is safe in cosmetics when formulated to be nonsensitizing, based on the results of a quantitative risk assessment or similar methodology; however, at no point should concentrations exceed 7.5 ppm in leave-on products or 15 ppm in rinse-off products.

Pharmacokinetics of 2-phenoxyethanol and its major metabolite, phenoxyacetic acid, after dermal and inhaled routes of exposure: application to development PBPK model in rats

2-Phenoxyethanol (PE), ethylene glycol monophenyl ether, is widely used as a preservative in cosmetic products as well as in non-cosmetics. Since PE has been used in many types of products, it can be absorbed via dermal or inhaled route for systemic exposures. In this study, the pharmacokinetic (PK) studies of PE and its major metabolite, phenoxyacetic acid (PAA), after dermal (30mg and 100mg) and inhaled administration (77mg) of PE in rats were performed. PE was administered daily for 4days and blood samples were collected at day 1 and day 4 for PK analysis. PE was rapidly absorbed and extensively metabolized to form PAA. After multiple dosing, the exposures of PE and PAA were decreased presumably due to the induction of metabolizing enzymes of PE and PAA. In dermal mass balance study using [14C]-phenoxyethanol ([14C]PE) as a microtracer, most of the PE and its derivatives were excreted in urine (73.03%) and rarely found in feces (0.66%). Based on these PK results, a whole-body physiologically-based pharmacokinetic (PBPK) model of PE and PAA after dermal application and inhalation in rats was successfully developed. Most of parameters were obtained from the literatures and experiments, and intrinsic clearance at steady-state (CLint,ss) were optimized based on the observed multiple PK data. With the developed model, systemic exposures of PE and PAA after dermal application and inhalation were simulated following no-observed-adverse-effect level (NOAEL) of 500mg/kg/day for dermal application and that of 12.7mg/kg/day for inhalation provided by the Environmental Protection Agency. The area under the concentration-time curve at steady state (AUCss) in kidney and liver (and lung for inhalations), which are known target organs of exhibiting toxicity of PE, as well as AUCss in plasma of PE and PAA were obtained from the model.

Development of Poly(3,4-Ethylenedioxythiophene) (PEDOT) Electropolymerized Sorbent-Based Solid-Phase Microextraction (SPME) for the Determination of Parabens in Lake Waters by High-Performance Liquid Chromatography – Tandem Mass Spectrometry (HPLC-MS/MS)

Parabens are widely used as antimicrobial preservatives in cosmetic products and pharmaceuticals. Therefore, their presence in the environment is considered to be serious and their determination is important. This paper reports the development and validation of a new method based on solid-phase microextraction (SPME) and high-performance liquid chromatography – tandem mass spectrometry (HPLC-MS/MS) for the simultaneous determination of five parabens (methylparaben (MP), ethylparaben (EP), propylparaben (PP), butylparaben (BP) and benzylparaben (BzP)) in surface water. The polymer sorbent was obtained by the electropolymerization of 3,4-ethylenedioxythiophene on a stainless steel spring support. The parameters affecting the extraction efficiency of parabens were optimized. Under optimal conditions, the extraction recoveries ranged from 88 to 98% except for BzP (70%). Good linear responses were obtained with correlation coefficients (r2) exceeding 0.999. The detection limits were from 0.004 to 0.28 µg L−1. The method was successfully applied for the determination of parabens in lake water.

Interference-free analysis of multi-class preservatives in cosmetic products using alternating trilinear decomposition modeling of liquid chromatography diode array detection data

In this work, a simple and effective strategy was proposed based on the combination of liquid chromatography diode array detection (HPLC-DAD) with second-order calibration method for fast and simultaneous determination of twelve preservatives in a variety of cosmetic products. The twelve preservatives were completely eluted out within 10.5 min under a simple sample preparation step. The proposed method shows “second-order advantage”, which enables one to accurately quantify the twelve preservatives in complex cosmetics in the presence of co-eluting chromatographic peaks and diverse unknown interferences. As a result, the consumption of organic solvents was markedly reduced and analysis time was greatly shortened. All target analytes showed good linearity in the calibration range with root-mean-square error of calibration (RMSEC) less than 0.84. The average spiked recoveries for all target analytes were in the range of 93.9%-110.5% with standard deviations less than 9.3%. In addition, analytical figures of merit were calculated to validate the performance of the proposed method. All these results demonstrated that the developed strategy was fast, green and accurate. Consequently, it could be used as an attractive alternative for the determination of multiple preservatives in complex cosmetic samples.

Safety Assessment of Polyaminopropyl Biguanide (Polyhexamethylene Biguanide Hydrochloride) as Used in Cosmetics.

The Expert Panel for Cosmetic Ingredient Safety (Panel) reviewed the safety of Polyaminopropyl Biguanide (polyhexamethylene biguanide hydrochloride), which functions as a preservative in cosmetic products. The Panel reviewed relevant data relating to the safety of this ingredient and concluded that Polyaminopropyl Biguanide is safe in cosmetics in the present practices of use and concentration described in the safety assessment, when formulated to be nonirritating and nonsensitizing, which may be based on a quantitative risk assessment or other accepted methodologies. The Panel also concluded that the data are insufficient to determine the safety of Polyaminopropyl Biguanide in products that may be incidentally inhaled.

Rapid and Simple Determination of Honokiol and Magnolol in Cosmetic Products by Liquid Chromatography with Ultraviolet Detection

A rapid and simple analytical method based on liquid chromatography – ultraviolet detection has been developed and validated for the simultaneous determination of two high added-value cosmetic ingredients, honokiol and magnolol, in commercial cosmetic samples. These compounds from the Magnolia plant present demonstrated benefits for the skin, such as antioxidative and anti-inflammatory properties, besides of antimicrobial and antifungal capacity, which may lead to their possible use as alternative preservatives in cosmetic products. The proposed method has been successfully validated showing good linearity, limits of detection and quantification in the low µg mL−1 level (0.06 to 0.07 µg mL−1 and 0.19 to 0.24 µg mL−1, respectively) and good repeatability (relative standard deviation below 9%). The proposed method has been evaluated by analyzing a laboratory-made cosmetic sample containing known concentrations of the analytes, providing low relative errors (-6% for honokiol and −4% for magnolol) and quantitative recovery values (96 to 111%). Finally, the proposed analytical method has been applied to the determination of both analytes in eight commercial cosmetic samples with different properties, obtaining quantitative recovery values (93 to 115%) and thus showing that matrix effects are negligible. In summary, the results show that this firstly proposed method for honokiol and magnolol determination in cosmetic products is accurate and useful for the routinely quality control of these consumer products containing both ingredients.

Amended Safety Assessment of Parabens as Used in Cosmetics.

The Expert Panel for Cosmetic Ingredient Safety (Panel) assessed the safety of 21 parabens as preservatives in cosmetic products. All of these ingredients are reported to function in cosmetics as preservatives; however, 5 are reported to also function as fragrance ingredients. The Panel reviewed relevant data relating to the safety of these ingredients under the reported conditions of use in cosmetic formulations. The Panel concluded that 20 of the 21 parabens included in this report are safe in cosmetics in the present practices of use and concentration described in this safety assessment when the sum of the total parabens in any given formulation does not exceed 0.8%. However, the available data are insufficient to support a conclusion of safety for benzylparaben in cosmetics.