Acid In Cosmetic Products Research Articles

Safety Assessment of Capryloyl Salicylic Acid as Used in Cosmetics.

The Expert Panel for Cosmetic Ingredient Safety (Panel) reassessed the safety of Capryloyl Salicylic Acid in cosmetic products; this ingredient is reported to function as a skin conditioning agent. The Panel reviewed relevant data relating to the safety of this ingredient in cosmetic formulations, and concluded that the available data are insufficient to make a determination that Capryloyl Salicylic Acid is safe under the intended conditions of use in cosmetic formulations.

Magnetic molecularly imprinted polymer combined with solid-phase extraction for detection of kojic acid in cosmetic products

In this study, a new magnetic molecularly imprinted polymer Fe3O4@MIP is prepared via a surface molecularly imprinting technique; it is first applied as a magnetic solid phase extraction (MSPE) adsorbent for the selective and rapid extraction of kojic acid (KA) in cosmetic products. The as-prepared Fe3O4@MIP is characterized systematically, and is found to exhibit good monodispersity and high magnetic susceptibility in favor of fast separation. The adsorption capacity and equilibrium time of KA on the Fe3O4@MIP adsorbent are 314.0 mg/g and 30 min, respectively. In addition, the imprinting factor of Fe3O4@MIP is 2.09 for KA, which indicates that the prepared Fe3O4@MIP exhibits good selectivity for KA. Under the optimum experimental conditions, the KA in cosmetic products was successfully extracted with Fe3O4@MIP adsorbent and determined by ultraviolet–visible (UV–vis) spectrophotometry. Validation experiment shows that the developed method presents good linearity (50–500,000 μg/L), satisfactory precision (RSD, 2.5–4.6 %), and high recovery (92.4–104.6 %). The limit of detection (LOD) is 21.4 μg/L, and the enrichment factor is 299. These results suggest that this MSPE method coupled with UV–vis spectrophotometry holds great potential for efficient sample pretreatment and target molecule determination in real samples.

Sensitive Detection of Rosmarinic Acid Using Peptide-Modified Graphene Oxide Screen-Printed Carbon Electrode.

Peptides have been used as components in biological analysis and fabrication of novel sensors due to several reasons, including well-known synthesis protocols, diverse structures, and acting as highly selective substrates for enzymes. Bio-conjugation strategies can provide a simple and efficient way to convert peptide-analyte interaction information into a measurable signal, which can be further used for the manufacture of new peptide-based biosensors. This paper describes the sensitive properties of a peptide-modified graphene oxide screen-printed carbon electrode for accurate and sensitive detection of a natural polyphenol antioxidant compound, namely rosmarinic acid. Glutaraldehyde was chosen as the cross-linking agent because it is able to bind nonspecifically to the peptide. We demonstrated that the strong interaction between the immobilized peptide on the surface of the sensor and rosmarinic acid favors the addition of rosmarinic acid on the surface of the electrode, leading to an efficient preconcentration that determines a high sensitivity of the sensor for the detection of rosmarinic acid. The experimental conditions were optimized using different pH values and different amounts of peptide to modify the sensor surface, so that its analytical performances were optimal for rosmarinic acid detection. By using cyclic voltammetry (CV) as a detection method, a very low detection limit (0.0966 μM) and a vast linearity domain, ranging from 0.1 µM to 3.20 µM, were obtained. The novelty of this work is the development of a novel peptide-based sensor with improved performance characteristics for the quantification of rosmarinic acid in cosmetic products of complex composition. The FTIR method was used to validate the voltammetric method results.

New Paper-based Microfluidic Analytical Devices for Kojic Acid Assay Based on Double-sided Adhesive Tape

Kojic acid is an antioxidant used by the cosmetics industry but the excessive usage of kojic acid may cause harm to human health. Therefore, it is important to detect the content of kojic acid in cosmetic products. In this work, the low-cost and simple paper-based analytical devices (μPADs) based on double-sided adhesive tape were developed for the colorimetric detection of kojic acid. The μPADs were fabricated by dissolving double-sided adhesive tape in toluene and then making the patterned adhesive tape penetrate into the filer paper. Ferric nitrate was used as the reagent to react with kojic acid, and the product of their chelating reaction caused the color change from colorless to orange-red. The ImageJ software was used to analyze the color intensity and the corresponding correction curve was determined. The μPADs for the detection of kojic acid exhibited a wide linear range (0.05 - 4 mM) and the detectable limit was 0.05 mM. The good selectivity and reproducibility were also demonstrated.

Optimization of cleaning and analytical method for determination of arbutin, hydroquinone and kojic acid in cosmetic products

Optimization of cleaning and analytical method for determination of arbutin, hydroquinone and kojic acid in cosmetic products

Optimization of cleaning and analytical method for determination of arbutin, hydroquinone and kojic acid in cosmetic products

Optimization of cleaning and analytical method for determination of arbutin, hydroquinone and kojic acid in cosmetic products

Risk assessment of phenylbenzimidazole sulfonic acid in cosmetic products

Risk assessment of phenylbenzimidazole sulfonic acid in cosmetic products

An innovative nano‐sorbent for selective solid‐phase extraction and spectrophotometric determination of p‐amino benzoic acid in cosmetic products

A novel nano-sorbent was developed for selective extraction and pre-concentration of p-amino benzoic acid (PABA) prior to determination by spectrophotometry. Selective extraction of PABA from aqueous solutions was performed using a solid-phase extraction column packed with 200 mg of nickel-zinc-aluminium layered double hydroxide (Ni-Zn-Al LDH) as a nano-sorbent. Extraction procedure is based on the adsorption of p-amino benzoate ions on the Ni-Zn-Al-nitrate LDH and/or their exchanging with LDH interlayer nitrate ions. After elution of extracted analyte by 2.5 mL of 2 mol L(-1) NaCl solution, its concentration was determined spectrophotometrically at λmax = 268 nm. The spectrophotometry method gave a linear response for PABA within the range of 12.5-425.0 μg L(-1) with a correlation coefficient of 0.9994. In the optimum experimental conditions, the limit of detection and sorption capacity were 3.78 μg L(-1) and 21.25 mg g(-1) , respectively. The presented method uses mild separation conditions and is a sensitive, reproducible, simple, low-cost and environment-friendly technique that could be used for the extraction and determination of PABA in various cosmetic samples.

Quantification of sunscreen 2-phenylbenzimidazole-5-sulfonic acid in cosmetic products and water samples by HPTLC/densitometry with fluorescent detection

Abstract The water-soluble sunscreen 2-phenylbenzimidazole-5-sulfonic acid (PBS) was quantified in a sun-care product and water samples by thin layer chromatography followed by densitometric scanning in fluorescence mode (cut-off filter 370 nm, wavelength of excitation — 300 nm). Normal phase TLC was performed on silica gel 60 as stationary phase. Mobile phase used was ethyl acetate-ethanol-water 70:35:30 (v/v/v). The limit of detection (LOD) was 0.0004 μg spot-1, and the limit of quantification (LOQ) was — 0.001 µg spot−1 without any sample pre-concentration.

Quantification of ellagic acid in cosmetic products by using a partially preanodized screen-printed carbon electrode coupled with flow injection analysis.

A partially preanodized screen-printed carbon electrode (PSPCE*) coupled with flow injection analysis (FIA) was developed to raise the selectivity of ellagic acid (EA). To confirm the effectiveness of partial preanodization, two pretreated screen-printed carbon electrodes were electrochemically compared. One was a PSPCE* fabricated by potential cycling (-1.0 - +1.0 V vs. Ag/AgCl) to make the electrode surface partially preanodized and the other was a SPCE* fabricated by a high treatment potential (+2.0 V vs. Ag/AgCl). Cyclic voltammograms showed that the catalytic current of EA was observed at both the PSPCE* and SPCE*. No catalytic current of ascorbic acid 2-glucoside (AA2G) and magnesium ascorbyl phosphate (MAP) was observed at the PSPCE*. The PSPCE* selectively detected EA. The factors, which influence the EA response current, have previously been discussed. At the detection limit (0.012 ppm, S/N = 3), the linear calibration plot (R2 = 0.998) was attained for 0.1-50 ppm of EA solutions. A relative standard deviation of 4.37 and 3.90% was conducted for consecutive injections (n = 10) of 1 and 50 ppm EA, respectively. Finally, a practical application of the proposed method was demonstrated by the quantitative analysis of EA in skin whitening creams, and good recovery was obtained.

Determination of tranexamic acid in cosmetic products by high-performance liquid chromatography coupled with barrel plating nickel electrode

Tranexamic acid (TA) is an important reagent in cosmetic skin-whitening formulation and a drug for the inhibition of plasminogen to plasmin in blood. Since there is no chromophore in tranexamic acid molecule to enable direct analysis by UV–visible absorption spectrophotometry, derivatization is thus required by excluding use of UV or fluorescence detection. We report here a relatively simple electrochemical TA detection method by using a barrel plating nickel electrode. Chromatographic separation was performed on a Hamilton PRP-X100 anion-exchange column (150 mm × 4.1 mm i.d., 10 μm particle size) with a (85:15, v/v) mixture of 0.1 mol l −1 NaOH and acetonitrile as mobile phase and pumped at a flow rate of 0.9 ml min −1. By detecting at +0.55 V vs. Ag/AgCl, the calibration plot was linear in the concentration window of 3–1000 ppm with regression coefficient and detection limit (S/N = 3) of 0.9993 and 0.13 ppm (0.84 μmol l −1), respectively. Successive injections ( n = 10) of 50 ppm tranexamic acid showed a R.S.D. value of only 0.3% indicating good reproducibility of the proposed system. The method was successfully applied to the analysis of the content of tranexamic acid in cosmetic products and proved to be suitable for rapid and reliable quality control.

Determination of ethylenediaminetetraacetic acid, ethylenediaminedisuccinic acid and iminodisuccinic acid in cosmetic products by capillary electrophoresis and high performance liquid chromatography

A capillary electrophoresis (CE) and a high performance liquid chromatography (HPLC) method are described for the simultaneous determination of ethylenediaminetetraacetic acid (EDTA), S, S′-ethylenediaminedisuccinic acid (EDDS) and R, S-iminodisuccinic acid (IDS) complexing agents as their Fe(III) complexes in cosmetics like shower cream and foam bath. The non-biodegradable EDTA is used in combination with biodegradable analogues like EDDS and IDS in many commercial products. The HPLC method involves separation by reversed-phase ion pair chromatography on a C 18 column using methanol–formate buffer (20 mM tetrabutylammonium hydrogen sulfate, 15 mM sodium formate adjusted to pH 4.0 with formic acid) (10:90, v/v) as mobile solvent at a flow rate of 0.8 mL min −1 at 24 °C using UV detection at 240 nm. The CE separation was performed in a fused silica capillary of 50 μm i.d. with the total length of 50 cm with a 10 mM MES and MOPSO (pH 5.5) at an applied voltage of −25 kV. The samples were introduced by applying a 50 mbar pressure for 2 s. Absorbances at 215 and 225 nm were monitored for the detection of the complexes. The methodology performance of the two methods was evaluated in terms of linearity, limit of detection (LOD), limit of quantitation (LOQ) and reproducibility. The LOD values obtained from HPLC are low when compared with CE. The applicability of both the methods was demonstrated for the analysis of cosmetic products such as shower cream and foam bath. The results obtained by both CE and HPLC were found to be comparable and in good agreement.

Quantification of glycolic acid in cosmetic products using reversed phase high performance liquid chromatography

Many cosmetics contain keratolytic hydroxy acids to correct the effects of photoageing on human skin. Although methods exist for quantifying the alpha-hydroxy acid, glycolic acid in aqueous media, accurate methods for quantification in mixed hydrophobic and aqueous cosmetic creams and lotions are lacking. Glycolic acid was extracted from cosmetics using aqueous tetrahydrofuran (THF), separated with strong-anion exchange cartridges, and quantified by high performance liquid chromatography (HPLC) with UV-VIS detection without the paired-ion reagents. In a recovery experiment, the mean accuracy of the method was 100.6%. The dynamic range of the method allows for the detection of glycolic acid at concentrations used in over-the-counter cosmetics.

Simultaneous analysis of dehydroacetic acid, benzoic acid, sorbic acid and salicylic acid in cosmetic products by solid-phase extraction and high-performance liquid chromatography

A high-performance liquid chromatographic (HPLC) method for simultaneous determination of dehydroacetic acid (DHA), benzoic acid (BA), sorbic acid (SOA) and salicylic acid (SA) was developed for application to cosmetic products. Isocratic reversed-phase HPLC was employed for quantitative analysis using tetra- n-butylammonium (TBA) hydroxide as an ion-pair reagent. Cosmetic samples were purified by solid-phase extraction using Bond–Elut SI cartridges. Four acidic preservatives were eluted with methanol from cartridges. The HPLC assay was carried out using TSK gel ODS-80TM column (5 μm, 150×4.6 mm I.D.). The mobile phase consisted of a mixture of water and methanol (65:35, v/v) containing 2.5 mM TBA hydroxide adjusted with phosphoric acid to pH 7.0. The calibration curves of these preservatives showed good linearity with UV detection (235 nm). The correlation coefficients were better than 0.999 in all cases. The lower limits of detection (defined as a signal-to-noise ratio of about 3) were approximately 2.5 ng for DHA, 4.0 ng for BA, 2.0 ng for SOA and 5.5 ng for SA. The procedure described here is simple, selective and is suitable for quality control of finished cosmetic products.

Microdialysis of salicylic acid from viscous emulsion samples prior to high-performance liquid chromatographic determination

A micro-dialysis method was developed to isolate aqueous salicylic acid from viscous emulsion samples prior to HPLC determination. The optimal conditions for obtaining dialysis efficiency of salicylic acid as well as chromatographic conditions were investigated. Experimental results indicated that the dialysis achieved at pH 2.0 (0.025 M phosphate solution), 0.5 M NaCl addition, and 50-μl/min flow-rate of perfusion stream offered an optimal result. The proposed method provided a simple procedure for isolating salicylic acid from viscous emulsion samples. Application was illustrated by the analysis of salicylic acid in cosmetic products.

Determination of glycolic acid in cosmetic products by solid-phase extraction and reversed-phase ion-pair high-performance liquid chromatography

A procedure has been developed for the assay of glycolic acid in cosmetic products by reversed-phase high-performance liquid chromatography using an ion-pairing method. After dissolution in tetrahydrofuran–water (90:10, v/v), samples were purified by solid-phase extraction using silica-based strong anion-exchange cartridges and analysed directly on an Ultrasphere ODS column with UV detection at 210 nm and methanol–phosphate buffer (2:98, v/v), containing tetrabutylammonium iodide, as the mobile phase. Recovery of glycolic acid from different cosmetic matrices was between 92.4 and 96.2% and the precision of the method was better than 5.4% relative standard deviation. The procedure is rapid, simple, selective and it is suitable for routine analyses of commercial cosmetics.

Determination of free boric acid in cosmetic products.

A method is described that selectively extracts boric acid from cosmetic products. The boric acid is complexed with mannitol and titrated potentiometrically against sodium hydroxide solution. The method has been developed for a variety of substrates used for cosmetic products to cover the concentration range 0.5–5%m/m.