Versatile chromatographic method for catechin determination in development of topical formulations containing natural extracts

摘要

Catechin is found in several natural sources, as Eugenia dysenterica and Syzygium cumini extracts. Its antioxidant and UV-protective properties suggest a potential use in cosmetic and dermatological formulations. A simple analytical method capable of giving support to experiments performed along the development of topical formulations containing this natural substance (i.e. drug assay, skin permeation and stability studies), however, is still needed. Thus, this work aimed to develop and validate a selective HPLC method for catechin determination during the development of topical formulations. Separation was achieved using an RP-C-18 column (300x3.9mm; 10m), with a mobile phase of methanol-phosphoric acid 0.01m (15: 85, v/v), a flow rate of 0.8mL/min, temperature set at 40 degrees C and UV detection at 230nm. The method was linear in a range from 0.5 to 10.0g/mL (r=0.9998), precise with an overall variation coefficient of 5.5% and accurate with catechin recovery from the skin layers 85%. Additionally, the method was sensitive (limit of detection, 0.109g/mL; limit of quantification, 0.342g/mL) and selective against plant extracts, skin matrices and formulation interferents, as well as catechin degradation products. It was also robust regarding both methodology parameters and analytical stability.