Introduction: Achyrocline satureioides (marcela or macela) is a plant widely used in folk medicine in South America. Recently, there has been increasing interest for the development of skin care products containing A. satureoides extracts, due to its well-documented antioxidant, antiherpetic, and wound healing properties.
Objectives: The present study aimed to develop and validate a yet unexplored stability-indicating and robust ultra-fast liquid chromatography (UFLC) method for the simultaneous quantification of the main flavonoids of A. satureioides in extracts, nanoemulsions, and porcine skin layers.
Material and methods: The chromatographic separation of flavonoids quercetin, luteolin, and 3-O-methylquercetin was performed on a Luna C18 analytical column (100 mm × 2.0 mm i.d.; particle size 2.5 μm) using isocratic elution with methanol/phosphoric acid 1% (48:52 v/v) with a flow rate of 0.3 mL/min at 40°C.
Results: The method was found to be specific, linear (R > 0.998), precise, accurate, and robust for all flavonoids assayed in A. satureioides extract, nanoemulsions, and porcine ear skin. A low matrix effect was noted for all complex matrices. The stability-indicating UFLC method was evaluated by submitting isolated flavonoids, a mixture of standards, and A. satureioides extract to acidic, alkaline, oxidative, UV-A/UV-C light, and thermal stress conditions. No peaks were found co-eluting with the flavonoids of interest in all matrices. The robustness of the method was confirmed using Plackett-Burman experimental design.
Conclusion: The short run time (8 min) and reliability of the method could be useful for the determination of A. satureioides flavonoids in topical product development since extracts of this medicinal plant have been used to treat various skin disorders.
Keywords: Achyrocline satureioides flavonoids; nanoemulsions; porcine skin; retention/permeation studies; stability-indicating UFLC method.
© 2020 John Wiley & Sons, Ltd.