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The improvement of the rutin photostability and its prolonged in vitro antioxidant activity were studied by means of its association with nanostructured aqueous dispersions. Rutin-loaded nanocapsules and rutin-loaded nanoemulsion showed mean particle size of 124.30 ± 2.06 and 124.17 ± 1.79, respectively, polydispersity index below 0.20, negative zeta potential, and encapsulation efficiency close to 100%. The in vitro antioxidant activity was evaluated by the formation of free radical ·OH after the exposure of hydrogen peroxide to a UV irradiation system. Rutin-loaded nanostructures showed lower rutin decay rates [(6.1 ± 0.6) 10−3 and (5.1 ± 0.4) 10−3 for nanocapsules and nanoemulsion, respectively] compared to the ethanolic solution [(35.0 ± 3.7) 10−3 min−1] and exposed solution [(40.1 ± 1.7) 10−3 min−1] as well as compared to exposed nanostructured dispersions [(19.5 ± 0.5) 10−3 and (26.6 ± 2.6) 10−3, for nanocapsules and nanoemulsion, respectively]. The presence of the polymeric layer in nanocapsules was fundamental to obtain a prolonged antioxidant activity, even if the mathematical modeling of the in vitro release profiles showed high adsorption of rutin to the particle/droplet surface for both formulations. Rutin-loaded nanostructures represent alternatives to the development of innovative nanomedicines.

Adulteration of antidiabetic herbal medicines with hypoglycemic drugs has been reported as a recurrent practice throughout the world. In this context, a new method for the determination of metformin, chlorpropamide, glibenclamide and gliclazide by capillary zone electrophoresis (CZE) with capacitively coupled contactless conductivity detection (C 4 D) is described in this paper. The proposed method was applied to the evaluation of adulterants in samples of herbal formulations commercialized by compounding pharmacies for the treatment of diabetes mellitus. The method was shown to be suitable for the simultaneous evaluation of hypoglycemics as adulterants using a 20 mmol L À1 sodium acetate solution at pH 10.0 as the working electrolyte. The method allows for the quantification of the adulterants in concentrations higher than 0.24 mg per capsule for metformin, 0.42 mg per capsule for chlorpropamide, 0.15 mg per capsule for glibenclamide and 0.33 mg per capsule for gliclazide.

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A reverse-phase (RP)-HPLC method is reported for determining L-tyrosine, p-octopamine, synephrine, tyramine and hordenine as chemical markers of the species Citrus aurantium in raw material, dry extracts and phytotherapeutic herbal formulations. Using RP-HPLC with diode array detection (DAD) and gradient elution, the amines were determined in 12 different products from different Brazilian states labelled as containing C. aurantium. The presence of the amines was confirmed by mass spectrometry using electrospray ionisation (ESI-MS/MS). This RP-HPLC method allowed the separation of the amines from complex mixtures containing caffeine, ephedrine, salicin and other raw materials (e.g. Garcinia camboja, Phaseolus vulgaris, Caralluma fimbriata, Cassia nomane, Ephedra sp. and Cordia ecalyculata). The method proved useful and selective for inspecting herbal medicines containing p-synephrine and structural analogues. The herbal products analysed had a p-synephrine content ranging from 0.005 to 4.0% (w/w).