Simultaneous quantification of ethylene glycol and diethylene glycol in beer by gas chromatography coupled to mass spectrometry.

An analytical method for the simultaneous determination of ethylene glycol and diethylene glycol in beer was developed and validated according to current legislation. This method includes the application of sample dilution with ethanol followed by quantification using gas chromatography coupled to mass spectrometry. All figures of merit were within the limits established by regulation. The recoveries of the analytes, expressed as mean recovery, were between 91.9% and 108.9%. Precision, in terms of repeatability and intermediate precision, was established (relative standard deviations were lower than or equal to 10%). The limits of detection (10.0 and 5.0 mg.L-1 for ethylene glycol and diethylene glycol, respectively) and quantification (15.0 mg.L-1 for ethylene glycol and diethylene glycol) obtained were appropriate. Finally, the present method was applied for determination of ethylene glycol and diethylene glycol in 701 beer samples (from 67 different brands and 128 different labels), proving to be reliable.

Nanoemulsions loaded with amphotericin B: a new approach for the treatment of leishmaniasis.

This work aimed to develop nanoemulsions (NE) containing cholesterol and Amphotericin B (AmB) evaluating the influence of a lipophilic amine (stearylamine; STE) on drug encapsulation efficiency (EE), cytotoxicity on macrophages and in vitro antileishmanial activity. The EE of AmB in NE was nearly 100% regardless of STE concentration. Stability studies showed that AmB-loaded NE with or without STE were stable revealing that AmB content and EE remained constant after 180days. In significant contrast, the EE for AmB in NE without cholesterol drastically decreased showing that this co-surfactant significantly improved the retention of drug in NE. The electronic absorption and circular dichroism (CD) data revealed that the signal characteristic of self-associated free AmB, the most toxic form to the host cells, was virtually absent in the spectra of AmB-loaded NE. In agreement, NE-induced toxicity toward macrophages was significantly lower than that observed for the conventional AmB. STE enhanced both cytotoxicity and the activity against intracellular amastigotes of AmB-loaded NE. However, selectivity index values for AmB-loaded NE were considerably higher than that observed for conventional AmB. AmB-loaded and cholesterol-stabilized NE constitutes an attractive alternative for the treatment of leishmaniasis.

Amphotericin B-loaded nanocarriers for topical treatment of cutaneous leishmaniasis: development, characterization, and in vitro skin permeation studies.

Topical treatment of cutaneous leishmaniasis represents an exciting alternative for reducing toxicity associated with parenteral administration of conventional amphotericin B. This work aims to develop and to characterize amphotericin B-loaded new carriers and to investigate their potential for topical delivery by conducting permeation studies with pig ear skin in comparison with marketed formulations. Among other formulations, nanoemulsions were developed and characterized for size, encapsulation efficiency, and zeta potential. To mimic use conditions in topical therapy of cutaneous leishmaniasis, in vitro skin permeation experiments were conducted using a damaged skin model. High encapsulation efficiency (95%) and low particle size (239 nm) were obtained for amphotericin B-loaded nanoemulsion by employing an ion pairing between the drug and stearylamine. Amphotericin B permeation after 24 h across the dermal membrane was low, regardless of the type of formulation tested. In contrast, amphotericin B penetration into dermal membranes (microg/cm2) from solution (control), aqueous Amphocil, hydroalcoholic Amphocil, Fungizone, mixture Fungizone-Lipofundin, and NE was 17.5 +/- 4, 15.2 +/- 3, 9.6 +/- 3, 3.5 +/- 1, 1.7 +/- 0.3, and 1.1 +/- 0.1, respectively. Amphocil provided the best results, highlighted by its high improvement of dermal penetration of amphotericin B.