Agents In Cosmetic Products Research Articles

Simultaneous Determination of α-Arbutin, β-Arbutin, Kojic Acid, Nicotinamide, Hydroquinone, Resorcinol, 4-Methoxyphenol, 4-Ethoxyphenol and Vitamin C from Skin Lightening Products by LC-UV

Skin lightening products have become increasingly in demand in recent years, especially in Asian markets. Skin lightening products are expected to whiten the skin as well as to tone skin or to treat pigmentation disorders such as freckles, melasma, pregnancy markers, and age spots [1]. Arbutin (α-arbutin and β-arbutin), kojic acid, nicotinamide and vitamin C are commonly used skin-whitening agents in cosmetic products. Several studies showed that these agents were tyrosinase inhibitors [2]. Resorcinol is used for removing hard, scaly, or roughened skin. Hydroquinone, 4-methoxyphenol and 4-ethoxyphenol have been banned in the European Union for the topical use in skin lightening application due to the high incidence of ochronosis and leukomelanodema.

Safety Assessment of 1,2-Glycols as Used in Cosmetics

Caprylyl glycol and related 1,2-glycols are used mostly as skin and hair conditioning agents and viscosity agents in cosmetic products, and caprylyl glycol and pentylene glycol also function as cosmetic preservatives. The Cosmetic Ingredient Review (CIR) Expert Panel noted that, while these ingredients are dermally absorbed, modeling data predicted decreased skin penetration of longer chain 1,2-glycols. Because the negative oral toxicity data on shorter chain 1,2-glycols and genotoxicity data support the safety of the 1,2-glycols reviewed in this safety assessment, the Panel concluded that these ingredients are safe in the present practices of use and concentration described in this safety assessment.

A gas chromatography–mass spectrometric method to determine skin-whitening agents in cosmetic products

An analytical method is proposed here to determine three allowed (kojic acid, azelaic acid and arbutin) and two forbidden (resorcinol and hydroquinone) skin-whitening agents in cosmetics. The method is based on gas chromatography coupled with mass spectrometric detection, which allows the two prohibited target compounds to be identified unequivocally by means of their mass spectra acquired in full-scan mode at the retention time of these compounds. Owing to their low volatility, target analytes are derivatized using N,O-bis-(trimethylsilyl)trifluoroacetamide (BSTFA) (containing 1% trimethylchlorosylane) prior to injection into the chromatographic system. The accuracy and precision of the proposed method were evaluated by analysing a laboratory-made skin-whitening cosmetic sample containing known amounts of the five target compounds. The method can be easily applied by the manufacturers in the quality control of their own products, and also by safety authorities to prevent fraudulent operations and thus look after consumers' health. The proposed method was successfully applied to the analysis of nine commercial skin-whitening cosmetic products, showing that fraud was committed in four of the analyzed samples.

Polarographic determination of sunscreen agents in cosmetic products in micellar media

This paper introduces a simple, fast and reliable electroanalytical method for differential-pulse polarography based on electrochemical reduction at a dropping mercury electrode. The method was validated for the determination of 2-ethylhexyl-4-methoxycinnamate (EHMC) alone and in association with 4-methylbenzylidene camphor (MBC) or 2-hydroxy-4-methoxybenzophenone (BENZ-3) in samples of commercial cosmetic preparations. The supporting electrolyte that provided the best-defined and most intense peak current for EHMC determination was Britton-Robinson buffer (pH 4.0) in the presence of a cationic surfactant. Under optimized conditions, EHMC exhibited one single peak of reduction at −1.49 V versus Ag/AgCl. A limit of detection of 3.76 × 10 −8 mol L −1 and a limit of quantitation of 1.25 × 10 −7 mol L −1 were found for the pure EHMC standard. A good average recovery rate was reached for all the samples analyzed.

Simultaneous HPLC determination of hydrophilic whitening agents in cosmetic products

A high-performance liquid chromatographic method for quantifying four of the most common used hydrophilic whitening agent—glycolic acid (GA), ascorbic acid (AA), arbutin (ART) and Mg ascorbyl phosphate (MAP), has been developed. Isocratic separation was performed using a C18 column with ion-pair agent as mobile phase. The analytes were detected by ultraviolet light absorption at the wavelength of 220 and 240 nm, respectively. Calibration curves were found to be linear in the 8.0–36 mg/ml (GA), 10.0–300 μg/ml (AA and ART), and 5.6–451 μg/ml (MAP). The correlation coefficient of linear regression analysis were with the range 0.9974–0.9997. Recoveries of the four analytes were between 94.8 and 100.1% and the precision of this method was better than 6.9% relative standard deviation (R.S.D.) ( n=3). It was found that AA degraded in an aqueous solution. To be sure that AA was stable during the HPLC analysis, all analytes were dissolved in distilled water and these solutions were purged with nitrogen gas to remove oxygen and stored at 25 °C. The testing results show that the procedure is rapid, simple, selective method and it is suitable for routine analysis of commercial cosmetics.

Simultaneous Determination of Magnesium L-Ascorbyl-2-Phosphate and Kojic Acid in Cosmetic Bleaching Products by Using a Microbore Column and Ion-Pair Liquid Chromatography

A rapid, sensitive, and reliable method was developed for the simultaneous determination of magnesium L-ascorbyl-2-phosphate (AS-PM) and kojic acid (KA), commonly using bleaching agents in cosmetic products. The method uses a prepacked C18 microbore column for ion-pair liquid chromatography with photodiode array detection. The eluant is 0.5mM tetrabutylammonium bromide and 0.05M phosphate buffer, pH 5, containing 5% methanol, at a flow rate of 70 microL/min. The determinations of AS-PM and KA were linear in the range of 0.5-1,000 and 0.25-500 ng, respectively. The precision of the assay ranged from 0.31 to 2.19%, and the detection limits (signal-to-noise ratio = 3) were 0.04 and 0.02 ng for AS-PM and KA, respectively.

Determination of sunscreen agents in cosmetic products using microwave-assisted extraction and liquid chromatography

Microwave-assisted extraction (MAE), was used to extract sunscreen agents from cosmetic products. The extracts were analyzed by liquid chromatography (LC). The present method allows the determination of three sunscreen agents, Eusolex 2292, 4360 and 6300. The precision of the assay at 40 μg/ml of sunscreen agents ranged from 1.5 to 2.2%, and the detection limits were 2.0–4.0 ng/ml.

Determination of sunscreen agents in cosmetic products by supercritical fluid extraction and high-performance liquid chromatography

A rapid supercritical fluid extraction (SFE) procedure for the isolation of five of the most common sunscreen agents (2-ethylhexyl- p-dimethylaminobenzoate, 2-hydroxy-4-methoxybenzophenone, 2-ethylhexyl- p-methoxycinnamate, 4-methylbenzylidene camphor and 4- tert.-butyl-4′-methoxydibenzoylmethane) from cosmetic products is described. Investigation of the factors affecting the extraction efficiency in SFE indicated that sunscreen recoveries were affected mainly by the supercritical CO 2 pressure and by the trapping method. The sunscreens were analyzed by reversed-phase high-performance liquid chromatography after a 10-min extraction of the cosmetic product with CO 2 at 250 bar and 40°C, using sequential glass surface and C 18 sorbent as collection system. A quantitative comparison of SFE with a liquid extraction procedure was performed on commercial cosmetics. The SFE method yielded recoveries higher than 94.8% compared with conventional liquid extraction and exhibited a precision better than 5.3% relative standard deviation. Moreover, SFE minimized sample handling, reduced the consumption of harmful solvents and afforded a more effective purification of the cosmetic matrices.

A Rapid and Selective Method for Determining Potential Nitrosating Agents in Cosmetic Products by Chemiluminescence Detection of Nitric Oxide

A method was developed for rapid and selective determination of potential nitrosating agents at the part-per-billion level in cosmetic products. These compounds are chemically reduced to nitric oxide, which is determined by its chemiluminescent reaction with ozone. Suspended materials and colors in cosmetic products do not interfere. Hence their removal before analysis is not required. A detection limit of 33 ppb, calculated as nitrite, was obtained. No false-positive interferences were observed from antifoaming agents, several N-nitroso compounds, and nitrate up to 20 ppm. Among cosmetic products surveyed, potential nitrosating agents were found at levels ranging from 113 to 5021 ppb. No consistent relationship was found between levels of potential nitrosating agents and N-nitrosamines in the same products. However, the highest levels of nitrosating agents were most often associated with the highest levels of N-nitrosamines known to be present in the products.

High-performance liquid chromatographic assay for common sunscreening agents in cosmetic products, bovine serum albumin solution and human plasma

This paper reports the development of a reversed-phase high-performance liquid chromatographic assay for quantifying five of the most common sunscreen agents, namely 2-ethylhexyl- p-dimethyl aminobenzoate (Escalol 507), 2-ethylhexyl- p-methoxycinnamate (Parsol MCX); 4- tert.-butyl-4′-methoxydibenzoylmethane (Parsol 1789), 2-hydroxy-4-methoxybenzophenone-3 (oxybenzone) and 2-ethylhexyl-salicylate (octylsalicylate). The assay permits analysis of the sunscreen agents in formulations and in biological fluids, including bovine serum albumin (BSA) solution, a common additive to in vitro skin diffusion cell receptor fluids, as well as human plasma. Separation was achieved using an ODS C 18 column with a methanol-water (88:12) mobile phase. The analytes were detected by ultraviolet light absorption at a wavelength of 315 nm. The assay was linear with minimum detectable limits, calculated as greater than 3-times the baseline noise level: for oxybenzone and Escalol 507, 0.05 μg/ml; for Parsol 1789 and Parsol MCX, 0.1 μg/ml; for octylsalicylate, 1 μg/ml. Recoveries from both plasma and 2% BSA were within the range 89–107%. The inter- and intra-day coefficients of variation for the five agents were not more than 4% at the upper end of the linear range and not more than 10% at the lower end. Preliminary stability studies of the sunscreen agents in a commercial product and in two diffusion cell receptor fluids were also conducted.

Determination of salicylate- and benzophenone-type sunscreen agents in cosmetic products by gas chromatography-mass spectrometry

A novel simple method to detect salicylate- and benzophenone-type sunscreen agents in cosmetic products by gas chromatography-mass spectrometry (GC-MS) has been developed. Seven sunscreen agents (two salicylate-type and five benzophenone-type) were used for this study. Sunscreen agents and cosmetic product solutions were prepared by dissolving in dimethylformamide, and silylated with bis-trimethylsilyltrifluoroacetamide-trichloro-methylsilane (BSTFA). Silylated sunscreen agents were separated on a cross-linked methyl silicone gum column. The identification of each sunscreen agent was accomplished by retention time and mass spectrum library search with a computer, and the quantitation was made in the selected-ion monitoring (SIM) mode of GC-MS. Silylation increased the detection limits of all sunscreen agents about 20–170-fold. Linearity was maintained over the range 1–300 μg ml for each sunscreen agent. Each cosmetic product (i.e. sun lotion, sun cream and sun cream foundation) was found to contain amounts of the sunscreen agents. This method was sensitive and gave 95.2–104.1% recovery of each sunscreen agent from these cosmetic products. From these results, we concluded that silylation with BSTFA followed by GC-MS analysis allows the simple, convenient and exact determination of sunscreen agents from cosmetic products.

Determination of sun-screen agents in cosmetic products by micellar liquid chromatography

A micellar liquid chromatographic method was developed for the quantitative determination of sun-screen agents in cosmetic products. The qualitative analysis of parabens is also feasible. Excellent linearity was obtained ( r = 0.999) and recoveries were generally greater than 98%. A variety of commercial formulations were analyzed.

Determination of sun-screen agents in cosmetic products by reversed-phase high-performance liquid chromatography : Part II.

As part of a study concerning the determination by high-performance liquid chromatography (HPLC) of sun-screen agents in cosmetics in order to verify their adherence to legislation within the European Economic Community (EEC), we have extended our investigation to a series of compounds commonly employed in suntan preparations as UV absorbers. We report the results of an analysis performed on 85 samples of commercial suntan cosmetics

Determination of sunscreen agents in cosmetic products by gas chromatography and gas chromatography—mass spectrometry

Determination of sunscreen agents in cosmetic products by gas chromatography and gas chromatography—mass spectrometry

Determination of sunscreen agents in cosmetic products by reversed-phase high-performance liquid chromatography

Description d'une methode HPLC pour la determination rapide et simultanee de six produits antisolaires (Cinoxate, Oxybenzone, Eusolex 8020, Escalol 507, Parsol 1789 et Parsol MCX) dans des cosmetiques

Determination of sun-screen agents in cosmetic products by reversed-phase high-performance liquid chromatography

Determination of sun-screen agents in cosmetic products by reversed-phase high-performance liquid chromatography