A Validated Solid-Phase Extraction HPLC Method for Determination of the Major Flavonoid Glycoside of Kalanchoe pinnata Leaf Extract in Cosmetic Nanoemulsions: A Potential New Sustainable Active Ingredient Widely Present in Brazilian Biodiversity
摘要
Kalanchoe pinnata (Lam.) Pers., Crassulaceae, popularly known as “saião,” is widely distributed in Brazil and has a phytochemical constitution rich in flavonoids. In this context, the entire chain supply can be developed by Brazil industries to obtain a cosmetic formulation with its bioactive leaf extract, such as nanoemulsions. For this, a method for quantification of a marker is required to ensure the reproducibility of formulations containing K. pinnata leaf extract. Here, we present a reliable quantification method for nanoemulsions based on the content of quercetin 3-O-α-L-arabinopyranosyl-(1 → 2)-O-α-L-rhamnopyranoside, the main flavonoid glycoside identified in K. pinnata leaf extract. Given the complexity of the leaf extract and its formulation, sample preparation via solid-phase extraction was carried out using Florisil cartridges. The developed HPLC method used a C8 column in isocratic mode. The working range was established from 70 to 130 µg/ml, based on a nanoemulsion sample containing 1% (w/v) of K. pinnata extract. The selectivity of the method for the quercetin 3-O-α-L-arabinopyranosyl-(1 → 2)-O-α-L-rhamnopyranoside marker was confirmed by DAD. The method demonstrated to be linear and homoscedastic in the evaluated range. The limits of detection and quantification were 6.1 and 20.4 µg/ml, respectively. Quercetin 3-O-α-L-arabinopyranosyl-(1 → 2)-O-α-L-rhamnopyranoside recovery values ranged from 97.9 to 100.7%, with standard deviations of less than 4%, and without matrix effect interference. Therefore, SPE-HPLC methods were successfully developed and validated, fitted-for-purpose, allowing for their application in the quality control of sustainable and innovative cosmetic formulations containing K. pinnata extract.
Graphical Abstract