RESUMO
In-depth characterization of protein and lipid fractions from cow and camel milk (four breeds; CM-1 to 4), their functional and thermal properties and bioactivity upon simulated gastro-intestinal digestion was reported. Results revealed that proteins from cow and camel milk showed a noticeable separation on sodium dodecyl sulphate-polyacrylamide gel electrophoresis and high-performance liquid chromatography. Functional properties of whole milk proteins from cow and camel milk at different pH revealed that emulsifying activity index (EAI), foaming capacity (FC) and protein solubility was higher towards acidic and alkaline pH and lowest at isoelectric point (pHâ¯=â¯4). Moreover, the water absorption capacity (WAC) and solubility in water were higher in milk from cow (CW) compared to those from camel breeds (CM 1-4). Camel milk, which contains lower saturated and higher unsaturated fatty acids and demonstrated higher antioxidative and angiotensin-1 converting enzyme (ACE) inhibitory potential compared to cow milk upon simulated gastro-intestinal digestion, can be considered as a healthier option.
Assuntos
Anti-Hipertensivos/análise , Antioxidantes/análise , Lipídeos/análise , Proteínas do Leite/análise , Leite/química , Inibidores da Enzima Conversora de Angiotensina/química , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Animais , Anti-Hipertensivos/farmacologia , Camelus , Bovinos , Cromatografia Líquida de Alta Pressão , Digestão , Eletroforese em Gel de Poliacrilamida , Ácidos Graxos/análise , Concentração de Íons de Hidrogênio , Ponto Isoelétrico , Proteínas do Leite/químicaRESUMO
The objective of this study was to investigate the effect of the preparation method on the physico-chemical properties of complexes prepared between beta-cyclodextrin (beta-Cyd) and benzocaine (BZC). In particular, the effectiveness of a new technique based on supercritical carbon dioxide (SC CO(2)) for preparing solid drug-cyclodextrin complexes was investigated and compared to other more conventional methods such as kneading (KN), co-evaporation (COE), co-grinding (GR) and sealed-heating (S.H.). Effects of temperature, pressure and exposure time on the properties of complexes prepared by SC CO(2) technology were also studied. The different systems were characterized by differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), powder X-ray diffractometry (PXRD) and dissolution test according to the dispersed amount method. The co-grinding (GR) method resulted in amorphous products while other methods led to crystalline or partially amorphous products depending on both the method and its experimental conditions. SC CO(2) method revealed to be an effective technique for preparing solid systems between beta-cyclodextrin and benzocaine, avoiding the use of organic solvents (and problems of their complete removal) and allowing an easy scale-up of the process. As for the influence of the experimental conditions in promoting the solid-state drug-carrier interaction when using the SC CO(2) method, temperature seemed to play the major role, whereas pressure and exposure times had more limited effects. Dissolution tests confirmed a limited but favourable effect in increasing the exposure time, while indicated a possible interaction effect between temperature and pressure in influencing the dissolution performance of the final product. The best product obtained by the SC CO(2) method showed dissolution properties similar to those of the co-ground product and only slightly lower than the system obtained by sealed-heating, which was the most effective technique.
Assuntos
Anestésicos Locais/química , Benzocaína/química , Cromatografia com Fluido Supercrítico/métodos , Portadores de Fármacos , Tecnologia Farmacêutica/métodos , beta-Ciclodextrinas/química , Varredura Diferencial de Calorimetria , Dióxido de Carbono/química , Química Farmacêutica , Cristalografia por Raios X , Pós , Pressão , Solventes/química , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Fatores de TempoRESUMO
The main objective of this study was to improve the inclusion formation between itraconazole and beta-cyclodextrin and thus enhance dissolution amount and bioavailability characteristics of itraconazole. Inclusion complexes between itraconazole and beta-cyclodextrin were prepared using simple physical mixing, conventional coprecipitation method, and supercritical carbon dioxide (SC CO(2)). Effects of process variables (temperature, pressure) and drug:cyclodextrin ratio on inclusion yield and thermal behavior of the solid complexes prepared by SC CO(2) were studied and compared to those obtained by physical mixing and coprecipitation methods. In addition, dissolution amounts of the products obtained by different methods were measured in gastric fluid. Finally, pharmacokinetic studies of the inclusion complexes were conducted in male Wistar rats to assess the bioavailability of the prepared complexes. Results showed that temperature, pressure and itraconazole:beta-cyclodextrin ratio had significant effects on the inclusion yield of the complex prepared by SC CO(2) method. Higher inclusion yields were obtained in the SC CO(2) method as compared to physical mixing and coprecipitation methods. In vivo drug pharmacokinetic studies showed that the itraconazole-beta-cyclodextrin product prepared using SC CO(2) gave higher bioavailability of itraconazole (in blood, liver and kidney of male Wistar rats) as compared to the products obtained by physical mixing or coprecipitation methods.
Assuntos
Dióxido de Carbono/química , Cromatografia com Fluido Supercrítico/métodos , Itraconazol/química , Itraconazol/farmacocinética , beta-Ciclodextrinas/química , beta-Ciclodextrinas/farmacocinética , Animais , Disponibilidade Biológica , Varredura Diferencial de Calorimetria , Dióxido de Carbono/farmacocinética , Precipitação Química , Composição de Medicamentos , Excipientes , Suco Gástrico/química , Masculino , Pressão , Ratos , Ratos Wistar , Solubilidade , Espectrofotometria Ultravioleta , Temperatura , Distribuição TecidualRESUMO
Phase-solubility techniques were used to assess the formation of inclusion complex between itraconazole and beta-cyclodextrin. The stability constant and free energies of transfer of itraconazole from aqueous solution to the cavity of beta-cyclodextrin were calculated. Itraconazole solubility in supercritical carbon dioxide (SC CO(2)) was measured at different temperatures and pressures. Drug formulations of itraconazole were prepared by complexation of the drug into beta-cyclodextrin using SC CO(2). Effects of temperature and pressure on inclusion yield of the prepared complexes were studied. The solvent-free inclusion complexes obtained from this method were characterized by UV spectroscopy, differential scanning calorimetry, powder X-ray diffraction, and scanning electron microscopy and compared to those obtained from physical mixing and coprecipitation methods. Results showed that beta-cyclodextrin significantly improved solubility of itraconazole in aqueous solutions. The free energies of transfer of itraconazole from aqueous solution to the cavity of beta-cyclodextrin increased negatively with increasing beta-cyclodextrin concentration. Higher inclusion yields were obtained in the SC CO(2) method compared to physical mixing and coprecipitation methods. Both temperature and pressure had significant effects on itraconazole solubility in SC CO(2) and the inclusion yield of the complex prepared by SC CO(2) method.
Assuntos
Dióxido de Carbono/química , Itraconazol/química , beta-Ciclodextrinas/química , Varredura Diferencial de Calorimetria , Composição de Medicamentos , Estabilidade de Medicamentos , Excipientes , Microscopia Eletrônica de Varredura , Solubilidade , Espectrofotometria Ultravioleta , Água/química , Difração de Raios XRESUMO
OBJECTIVES: The objective of the present study was to evaluate how effective tobacco tax increase has been in increasing price of tobacco products and reducing tobacco consumption in the Gambia. In addition, it tests the hypothesis that tobacco tax revenue grows while tobacco consumption decreases as a result of tax and price increase. SETTING: The study is designed at the macroeconomic level to examine the import of tobacco products and revenue collected from tobacco taxation in a low-income setting. PARTICIPANTS: The participants of this study are the government officials employed in the Ministry of Finance and Economic Affairs (MoFEA), the Gambia and the Gambia Revenue Authority, who are in charge of planning and implementing the tobacco tax policy in the Gambia. INTERVENTIONS: The study includes 2 consecutive interventions in tobacco tax policy in the Gambia. The first intervention was moving the tax base for the uniform specific excise tax on cigarettes from weight to pack of cigarettes in 2013. The second intervention involved increasing the excise and the environmental tax on tobacco products in 2014. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome measures were the cost, insurance and freight value and the price of tobacco products. The secondary outcome measures included the import of tobacco products and tobacco tax revenue. RESULTS: In 2013-2014, the Gambia MoFEA raised the specific excise rate, which increased price, reduced consumption and generated significantly more government revenue from tobacco products. This is a clear evidence of the win-win outcome of raising tobacco tax. In addition, the Gambia has set the example of harmonising tax rates between tobacco products that reduces the substitution between tobacco products. CONCLUSIONS: The Gambia presents the best practice in tobacco taxation. There is need for documenting more country-specific evidence on the win-win outcome of raising tobacco tax.