An analytical GC-MS method to quantify methyl dihydrojasmonate in biocompatible oil-in-water microemulsions: physicochemical characterization and in vitro release studies.

Microemulsions (MEs) loaded with methyl dihydrojasmonate (MJ) were developed to improve the aqueous solubility of this drug. The composition of the formulations ranged according to the oil/surfactant ratio (O/S). The MEs were characterized according to diameter of droplets, X-ray diffraction and polarized light microscopy. The MJ identification and quantification was performed by gas chromatography-mass spectrometry (GC-MS). The MJ showed a retention time of ∼16.7 min for all samples. The obtained correlation coefficient from the calibration graph was 0.991. The developed analytical method was effective enough to quantify low and high concentrations of MJ. The increase of the O/S ME ratio led to a reduction of the droplet diameter. All formulations showed an amorphous structure and the behavior varied between isotropic and anisotropic systems. A decrease in the release of MJ with the increase of the O/S ratio in the formulations was observed. The analytical method developed for the quantitative determination of MJ is suitable to detect and quantify the drug compound from different compositions of MEs in the in vitro release test, and by analogy in other prolonged effects related to the drug reservoir effect of these systems was observed, revealing that ME can be a promising nanocarrier for MJ delivery to tumor cells.

Inorganic elemental analysis and identification of residual monomers released from different glass ionomer cements in cell culture medium / Análise elementar inorgânica e identificação de monômeros residuais orgânicos liberados por diferentes cimentos de ionômero de vidro

Introduction: Glass ionomer cements (GICs) release inorganic elements and organic residual monomers with the potential for deleterious effects on pulp cells. Objective: To identify and quantify inorganic elements present in different GICs and released components from these materials in cell culture medium. Material and Method: Samples of two resin-modified GICs for base/liner (Vitrebond and Fuji Lining LC), two resin-modified restorative GICs (Vitremer and Fuji II LC) and two conventional restorative GICs (Ketac Fil Plus and Ketac Molar Easymix) were prepared and analyzed by Energy-Dispersive X-Ray Fluorescence Spectrometry (EDXRF). Extracts of these materials were obtained by immersion of each sample in separate containers of DMEM for 24 h (total surface-liquid ratio = 45.7 mm²/mL). The extracts were analyzed by EDXRF and Gas Chromatography-Mass Spectrometry (GC-MS). Result: Higher percentages of strontium, silicon and aluminum were identified in Vitrebond, Vitremer, Fuji Lining LC, Fuji II LC, and Ketac Fil Plus, while zinc was detected only in Vitrebond. Ketac Molar Easymix presented a greater atomic composition of lanthanum, calcium, aluminum and silicon. Strontium was detected in the extracts from all materials except Ketac Molar Easymix; calcium was present in extracts from Ketac Fil Plus; zinc only in Vitrebond; and silicon in Fuji II LC extract. The analysis by GC-MS detected 2-hydroxyethyl-methacrylate (HEMA) in the extracts from all resin-modified GICs, and iodine benzene was detected only in the Vitrebond extract. Conclusion: Of the GICs sampled, Vitrebond released the highest number of components with cytotoxic potential.

Introdução: Os cimentos de ionômero de vidro (CIVs) liberam elementos inorgânicos e monômeros orgânicos residuais que têm o potencial de causar efeitos deletérios sobre as células pulpares. Objetivo: Identificar e quantificar os elementos inorgânicos presentes em diferentes CIVs, bem como os componentes liberados por estes materiais em meio de cultura celular. Material e Método: Espécimes cilindricos de dois CIVs modificados por resina para base/forramento (Vitrebond e Fuji Lining LC), dois CIVs modificados por resina restauradores (Vitremer e Fuji II LC) e dois CIVs convencionais restauradores (Ketac Fil Plus e Ketac Molar Easymix) foram preparados e analisados por Espectrometria de Fluorescência de Raios X por Energia Dispersiva (EDXRF). Em seguida, extratos de 24h desses materiais foram obtidos e analisados por EDXRF e por Cromatografia Gasosa/Espectrometria de Massa (CG/EM). Resultado: Os elementos inorgânicos identificados em maior porcentagem nos CIVs Vitrebond, Fuji Lining LC, Vitremer, Fuji II LC e Ketac Fil Plus foram estrôncio, silício e alumínio, enquanto o zinco foi detectado apenas no Vitrebond. O Ketac Molar Easymix apresentou maior porcentagem dos elementos lantânio, cálcio, alumínio e silício. Estrôncio foi detectado nos extratos de todos os materiais, exceto no Ketac Molar Easymix; cálcio estava presente no extrato do Ketac Fil Plus; zinco apenas no Vitrebond; e silício no extrato do Fuji II LC . O HEMA foi identificado nos extratos de todos os CIVs modificados por resina, e o iodobenzeno, somente no Vitrebond. Conclusão: Entre os CIVs estudados, o Vitrebond é o que libera mais componentes com potencial citotóxico.

Constituintes químicos de Cambessedesia espora DC - Melastomataceae / Chemical contituents from Cambessedesia espora DC - Melastomataceae

O fracionamento cromatográfico do extrato hexânico das partes aéreas de Cambessedesia espora DC - Melastomataceae levou ao isolamento dos ácidos palmítico, mirístico e esteárico, ß-Silosterol e do triterpeno fern-9(11)-en-3ß-ol. As substâncias foram identificadas por métodos espectroscópicos usuais (RMN, IV, CG/EM).