Kojic acid (KA) is an organic acid widely used in pharmaceutical industry, mainly as a skin lightening agent. Based on the ability of KA to form complexes with ions, we found the most possible kind of complex formed with cation aluminum. KA-Al3+ complex structures were studied using potentiometric and spectrophotometric (UV) titrations, FTIR and 13C NMR. The electronic spectroscopy showed that the KA-Al3+ complexes absorb at higher wavelengths (λmax= 305 nm) than do the non-complexed KA (λmax= 269 nm), confirming complexation. The IR spectra of KA complexed and not complexed allowed us to correlate the changes in the absorption of enol and carbonyl groups in absence and presence of Al3+ in aqueous solutions. The complexation suggested by the potentiometric titration and FTIR spectroscopy are in accordance with the data obtained from NMR results. Calculations based on quantum mechanics were utilized to understand the differences found in the noncomplexed and complexed KAH electronic spectra

We developed and validated a liquid chromatography tandem mass spectrometry (LC-MS/MS) method to quantify the antimalarials artesunate (ARS) and mefloquine (MFQ) in fixed-dose tablets. The detection was performed by a triple-quadrupole mass spectrometer in multiple reaction monitoring (MRM) in positive ion mode via electrospray ionization. Chromatographic separation was achieved with an XBridge C18 column (50 × 2.1 mm, 5 μm), using isocratic elution (350 μL min-1) of water/acetonitrile/methanol (30:35:35, v/v/v) containing 0.1% formic acid. The method was validated according to the International Conference of Harmonization (ICH) guidelines. The calibration curves obtained for ARS (400 to 600 ng mL-1) and MFQ (800 to 1200 ng mL-1) showed good linearity (r2 > 0.99), precision (relative standard deviation (RSD): ARS < 2.0%; MFQ < 1.9%), and accuracy (recoveries: ARS, 102.4-103.4%; MFQ, 97.4-101.6%), and were stable for 24 h at 8 ºC. The method was successfully applied to commercial tablets, and recoveries of 98.7 ± 4.7% (ARS) and 105.6 ± 3.13% (MFQ). The method developed is a reliable alternative for public quality inspection control with the advantage of tandem mass specificity and speed.

<p>Methods based on multivariate calibration and diffuse reflectance infrared Fourier transform (DRIFT) and ultraviolet (UV) spectroscopies were developed for the simultaneous determination of two veterinary pharmaceutical drugs, pyrantel pamoate and praziquantel, in commercial tablets. The best UV model was obtained with the full spectra, 200-400 nm, and partial least squares (PLS). The best DRIFT model was optimized by selecting the most predictive spectral regions with synergy interval PLS, 3998-3636 cm^-1, 3274-1824 cm^-1 and 1100-735 cm^-1. Both methods were validated according to Brazilian and international guidelines through the estimate of figures of merit, such as trueness, precision, linearity, analytical sensitivity, bias and residual prediction deviation (RPD). These methods were applied to the determination of the drugs in three different veterinary formulations commercialized in the Brazilian market and the results were compared with high performance liquid chromatography (HPLC). DRIFT was considered more suitable for the quality control of these formulations, because it is faster, does not use solvents and does not generate chemical waste.</p>

Malva sylvestris, popularly known as "malva" in Brazil, is a medicinal plant used for its antiinflammatory effects. However, multiple plants are known as "malvas" in Brazil; these species include Sida cordifolia ("malva-branca") and Pelargonium graveolens ("malva-cheirosa"). In this work, electrospray mass spectrometry metabolic fingerprints from these species were obtained by direct infusion of extracts of commercial samples, purchased as crushed dried leaves. The spectral data were used to classify these species using a partial least squares discriminant analysis method. The identities of all samples were confirmed by morphological analyses, emphasizing the trichomes morphology. While over 80% of the samples were labeled as M. sylvestris or "malva", in the present study only 37% of these samples were classified as M. sylvestris species. Approximately 50% of these samples were classified as S. cordifolia, whose consumption may be dangerous for patients with cardiovascular diseases. Thus, these analytical and chemometric procedures worked as a fast and simple method for classifying species of "malvas".