Chromatographic Methods for the Determination of Aminexil, Pyridoxine, and Niacinamide in a Novel Cosmetic Hair Preparation

The document from June 24, 2020, details the creation and validation of two chromatographic methods, High-Performance Liquid Chromatography (HPLC) and Thin-Layer Chromatography (TLC) with densitometry, for analyzing Aminexil (AX), Niacinamide (NA), and Pyridoxine HCl (PD) in a hair tonic. The HPLC method provided linearity for the compounds between 5-50 µg/mL and had retention times of 2.9, 3.8, and 5.4 minutes for AX, NA, and PD respectively, with a total run time of approximately 7 minutes. The TLC method showed linearity for AX at 0.25-1.25 µg/mL, NA at 2-7 µg/mL, and PD at 3-7 µg/mL. Both methods were sensitive, accurate, precise, and free from excipient interference, with correlation coefficients close to 1. The study concluded that these methods are suitable for routine quality control of these compounds in cosmetic hair preparations.