Encapsulation of eugenyl acetate in PHBV using SEDS technique and in vitro release evaluation.

Eugenyl acetate obtained via enzymatic esterification using Lipozyme TL IM enzyme was encapsulated in biopolymer poly(3-hydroxybutyrate-co-hydroxyvalerate) (PHBV) through solution-enhanced dispersion by supercritical fluids (SEDS). Produced particles were characterized by SEM and confocal microscopy techniques and in addition in vitro release assays were performed in isopropanol and ethyl acetate. Experimental micronization conditions comprised 8 and 10 MPa, 308 and 313 K and eugenyl acetate concentration ranging from 5 to 20 mg mL-1, keeping PHBV concentration constant (20 mg mL-1 in dichloromethane). The maximum encapsulation efficiency was 58.0 % for 5 mg mL-1of eugenyl acetate at 8 MPa and 308 K. The morphology of the encapsulated particles for most of the trials was spherical, with particle size ranging from 0.061 to 0.276 µm. Regarding the release in ethyl acetate and isopropanol solvents the higher the affinity of the encapsulated ester of these solvents, the faster the release was observed. These results demonstrate the importance of essential clove oil esterification reaction and encapsulation of the ester by SEDS method so that this encapsulated ester can be used in different industrial applications.

A pilot study of plasma metabolomic patterns from patients treated with ketamine for bipolar depression: evidence for a response-related difference in mitochondrial networks.

BACKGROUND AND PURPOSE: (R,S)-ketamine produces rapid and significant antidepressant effects in approximately 65% of patients suffering from treatment-resistant bipolar depression (BD). The genetic, pharmacological and biochemical differences between ketamine responders and non-responders have not been identified. The purpose of this study was to employ a metabolomics approach, a global, non-targeted determination of endogenous metabolic patterns, to identify potential markers of ketamine response and non-response. EXPERIMENTAL APPROACH: Plasma samples from 22 BD patients were analyzed to produce metabolomic patterns. The patients had received ketamine in a placebo-controlled crossover study and the samples were obtained 230 min post-administration at which time the patients were categorized as responders or non-responders. Matching plasma samples from the placebo arm of the study were also analysed. During the study, the patients were maintained on either lithium or valproate. KEY RESULTS: The metabolomic patterns were significantly different between the patients maintained on lithium and those maintained on valproate, irrespective of response to ketamine. In the patients maintained on lithium, 18 biomarkers were identified. In responders, lysophosphatidylethanolamines (4) and lysophosphatidylcholines (9) were increased relative to non-responders. CONCLUSIONS AND IMPLICATIONS: The results indicate that the differences between patients who respond to ketamine and those who do not are due to alterations in the mitochondrial ß-oxidation of fatty acids. These differences were not produced by ketamine administration. The data indicate that pretreatment metabolomics screening may be a guide to the prediction of response and a potential approach to the individualization of ketamine therapy.

Optimization and validation of a CE-LIF method for amino acid determination in biological samples.

There is increasing evidence that amino acids and related compounds are among the most important metabolites for living systems and their quantitative analysis is a continuous challenge for clinical and biochemical laboratories. The lack of chromophore group and their high polarity make the analytical process more difficult. A simple, rapid and inexpensive procedure based on CE-LIF has been optimised for biological samples such as urine and hippocampus tissue in terms of sample treatment, separation and quantitation. Around 30min were required for derivatization and determination by CE-LIF of l-alanine, l-aspartate, l-ß-aminoisobutyrate, d-ß-aminoisobutyrate, glycine, l-glutamate, l-glutamine, l-histidine, l-isoleucine, l-leucine, l-methionine, l-ornithine, l-phenylalanine, 4-hydroxy-l-proline, l-proline, l-serine, d-serine, taurine, threonine and l-valine. 4-Fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F) is the labelling agent used for obtaining fluorescence derivatives stables in urine up to 12h and up to 24h in hippocampus extracts in refrigerated conditions. Electrophoretic conditions were: 90mM borate buffer at pH 10.25 prepared with 12.5mM native ß-cyclodextrin. Applied voltage was +21kV. The method was validated for a representative group of amino acids in urine: l-phenylalanine, glycine, l-serine, d-serine and taurine. In hippocampus tissue the method was validated for the neurotransmitters: gamma-aminobutyric acid, l-glutamine, glycine, l-glutamate and l-aspartate. The method has been successfully applied to real samples, seven amino acids were quantified in 16 urine samples from healthy and type I diabetic children living in Spain, aged 8-11, and the results were statistically compared. They were in accordance to published reference values. Moreover neurotransmitters in hippocampus extracts were determined in samples of control mice and reported results were in accordance with previous references.

Efficiency of fly ash belite cement and zeolite matrices for immobilizing cesium.

The efficiency of innovative matrices for immobilizing cesium is presented in this work. The matrix formulation included the use of fly ash belite cement (FABC-2-W) and gismondine-type Na-P1 zeolite, both of which are synthesized from fly ash of coal combustion. The efficiency for immobilizing cesium is evaluated from the leaching test ANSI/ANS 16.1-1986 at the temperature of 40 degrees C, from which the apparent diffusion coefficient of cesium is obtained. Matrices with 100% of FABC-2-W are used as a reference. The integrity of matrices is evaluated by porosity and pore-size distribution from mercury intrusion porosimetry, X-ray diffraction and nitrogen adsorption analyses. Both matrices can be classified as good solidify systems for cesium, specially the FABC-2-W/zeolite matrix in which the replacement of 50% of belite cement by the gismondine-type Na-P1 zeolite caused a decrease of two orders of magnitude of cesium mean Effective Diffusion Coefficient (D(e)) (2.8e-09 cm(2)/s versus 2.2e-07 cm(2)/s, for FABC-2-W/zeolite and FABC-2-W matrices, respectively).

Simple high-performance liquid chromatography method for alpha-tocopherol measurement in Rosmarinus officinalis leaves. New data on alpha-tocopherol content.

A simple HPLC method for vitamin E (alpha-tocopherol) measurement in the leaves of Rosmarinus officinalis has been developed and validated. It has enabled new data for alpha-tocopherol content to be established. The leaves, recently harvested, were dried in a microwave oven and crushed; then, alpha-tocopherol was directly extracted from portions of ground material with acetone, by probe sonication. After centrifugation the acetonic extract was analysed by HPLC with ergocalciferol (vitamin D2) added as internal standard and a gradient elution with a Nucleosil C18 column at 35 degrees C. Validation parameters of the method can be considered adequate. For standards: linearity is r=0.999, recovery is 100+/-2%, intra-assay precision has RSD=+/-3% and inter-assay precision has RSD=+/-6%. For samples: linearity is r=0.99, recovery: 93+/-7%, intra-assay precision has RSD=+/-4% and inter-assay precision has RSD=+/-7%.