Hair Care Products Testing

Gimeno, Pascal, et al. Journal of Pharmaceutical and Biomedical Analysis 107 (2015): 386-393.

Hydrogen peroxide is a key oxidative agent in hair cosmetic products, widely used for bleaching and dyeing. However, excessive concentrations pose potential risks to hair integrity and scalp health. Accurate determination of hydrogen peroxide levels is crucial to ensure compliance with regulatory limits and product safety.

This study presents a validated high-performance liquid chromatography with ultraviolet detection (HPLC/UV) method for quantifying hydrogen peroxide in hair cosmetic products. The method is based on the oxidation of triphenylphosphine into triphenylphosphine oxide, which is then analyzed via HPLC/UV. To validate the approach, results were cross-compared with ceric sulfate titrimetry and the official iodometric titration method outlined in the Cosmetic Directive 82/434/EEC. The HPLC/UV method demonstrated excellent recovery rates (100%–110%) and precision (RSD < 3.0%), confirming its reliability for hydrogen peroxide quantification.

Analysis of commercial hair products revealed similar hydrogen peroxide concentrations across the different analytical methods, highlighting the accuracy of HPLC/UV. Market surveillance further identified certain products exceeding regulatory limits, underscoring the need for stringent quality control. This study establishes HPLC/UV as a robust, sensitive, and reproducible method for routine monitoring of hydrogen peroxide in hair cosmetic products, supporting regulatory compliance and consumer safety.

Tsiasioti, Apostolia, Constantinos K. Zacharis, and Paraskevas D. Tzanavaras. Molecules 28.2 (2023): 888.

Free histidine plays a vital role in hair care products, influencing hair structure and conditioning properties. As an essential amino acid, its presence enhances hair strength and moisture retention. However, accurate quantification is necessary to ensure product consistency and validate ingredient claims.

This study introduces a cation-exchange chromatography method with postcolumn derivatization and fluorimetric detection for determining free histidine in shampoos and conditioners. The method demonstrated high accuracy (recoveries: 83.5%–114.8%) and precision (RSD: 2.4%–5.6%) while minimizing matrix interferences. The detection limit reached as low as 1.5 mg/kg, enabling precise quantification in real samples.

Analysis of commercial hair care products confirmed histidine concentrations ranging from 70 to 535 mg/kg in formulations explicitly listing histidine as an ingredient, while it was undetectable in products without such claims. Spiking experiments further validated the method's reliability, reinforcing its suitability for quality control.

This study establishes a robust analytical technique for free histidine determination in hair care products, supporting regulatory compliance and product transparency while ensuring consumers receive scientifically validated formulations.

Masukawa, Yoshinori. Journal of Chromatography A 1108.1 (2006): 140-144.

The presence of basic dyes in hair care products is crucial for achieving temporary hair coloring effects. However, accurate identification and quantification of these dyes are essential for quality control and regulatory compliance, particularly since only certain dyes are permitted for use in major markets such as the USA, EU, and Japan.

This study establishes an optimized capillary electrophoretic (CE) method for analyzing five widely used basic dyes: Basic Red 76, Basic Brown 16, Basic Yellow 57, Basic Brown 17, and Basic Blue 99. A fused-silica capillary with a 100 mM acetic acid–ammonium acetate buffer containing 90% methanol was employed, ensuring precise dye separation while preventing peak tailing. The method demonstrated excellent reproducibility, linearity, and sensitivity, with recovery rates ranging from 93.3% to 111.2%.

Analysis of three commercial hair care products revealed distinct dye compositions, with up to three dyes detected per product. The CE method effectively separated and identified each dye without interference from other formulation components, confirming its reliability for product testing.

This validated CE method provides a robust tool for the accurate determination of basic dyes in hair care products, supporting quality assurance and regulatory adherence while ensuring product transparency for consumers.