Development and validation of a reversed‐phase high‐performance liquid chromatographic method for the quantitation and stability of α‐lipoic acid in cosmetic creams

Abstract

Objective To develop and validate a simple reversed‐phase HPLC method for the quantitation and evaluation of stability of α‐lipoic acid in cosmetics, according to International Conference on Harmonization (ICH) Guidelines. Methods The chromatography was performed on a reversed‐phase Luna C18, analytical column (150 × 4.6 mm id, 5 μm particle size) with a mobile phase of potassium dihydrogen phosphate (pΗ 4.5; 0.05 M) and acetonitrile (60:40, v/v) and a flow rate of 1.0 mL min−1 with UV detection at 340 nm. Accelerated and long‐term stability studies of α‐lipoic acid in cosmetic cream were conducted under various degradation conditions including acid, basis, oxidation, and thermal and photolytic degradation, according to European Medicines Agency Guidelines CPMP/ICH/2736/99. Results The limit of detection (LOD) for the cosmetic cream was 0.9 μg mL−1 and the limit of quantitation (LOQ) was 2.8 μg mL−1, while the retention time was 7.2 min. The method proved to be linear, precise and accurate. The stability results demonstrated the selectivity of the proposed method to the analysis of α‐LA, and the degradation products were determined and evaluated in specific stress conditions in cosmetic creams. The applicability of the method was tested in two different developed cosmetic products (cream with 1.5 % w/w and emulsion with 1.0 % w/w of LA) and proved to be reliable. Conclusion A reversed‐phase HPLC‐UV method was developed and fully validated for the analysis of α‐lipoic acid in cosmetics. It is the first reported application on the quantitation of lipoic acid in cosmetic creams, while at the same time evaluates the stability in forced degradation conditions, in new cosmetic formulations. It proved to be suitable for the reliable quality control of cosmetic products, with a run time of <8 min that allows for the analysis of large number of samples per day.

Bioanalytical methods for the detection of duloxetine and thioctic acid in plasma using ultra performance liquid chromatography with tandem mass spectrometry (UPLC-MS/MS)

“…HPLC is considered the most appropriate method for detecting TA [ 16 ]. Some methods have been reported to detect TA by LC [ 16 17 18 19 20 21 22 23 ]. The disadvantages of the previously reported methods include elaborate solid-phase extraction or derivatization steps [ 20 23 ], long run times (5–15 minutes) [ 16 17 19 ], and relatively poor sensitivity (0.13–5 μg/mL) [ 18 21 22 ].…”

“…Some methods have been reported to detect TA by LC [ 16 17 18 19 20 21 22 23 ]. The disadvantages of the previously reported methods include elaborate solid-phase extraction or derivatization steps [ 20 23 ], long run times (5–15 minutes) [ 16 17 19 ], and relatively poor sensitivity (0.13–5 μg/mL) [ 18 21 22 ]. Considering the limitations of these previous methods, a faster, simpler, and more sensitive detection method for duloxetine and TA is needed.…”

Simultaneous Analysis of Chlorogenic Acid, Epicatechin Gallate, and Rosmarinic Acid from the LOL (Ligularia stenofelphala, Orostachts japonica, Lavandula anfustifola) Cosmetic Composite and its Antioxidative Activity

“…Numerous analytical techniques have been used to quantify cosmetic ingredients through high-performance liquid chromatography (HPLC), such as HPLC coupled with other detectors, including ultraviolet (UV) detectors, mass spectrometers, and diode array detectors (DADs) (Papageorgiou et al, 2020). However, high-performance liquid chromatography with a diode array detector (HPLC-DAD) is highly recommended for analyzing herbal combinations because it offers 3D analyses and a wide array of mobile phases while being more affordable and resistant to contamination.…”