Stearic acid, beeswax and carnauba wax as green raw materials for the loading of carvacrol into nanostructured lipid carriers

The use of lipid nanoparticles as drug delivery systems has been growing over recent decades. Their biodegradable and biocompatible profile, capacity to prevent chemical degradation of loaded drugs/actives and controlled release for several administration routes are some of their advantages. Lipid nanoparticles are of particular interest for the loading of lipophilic compounds, as happens with essential oils. Several interesting properties, e.g., anti-microbial, antitumoral and antioxidant activities, are attributed to carvacrol, a monoterpenoid phenol present in the composition of essential oils of several species, including Origanum vulgare, Thymus vulgaris, Nigellasativa and Origanum majorana. As these essential oils have been proposed as the liquid lipid in the composition of nanostructured lipid carriers (NLCs), we aimed at evaluating the influence of carvacrol on the crystallinity profile of solid lipids commonly in use in the production of NLCs. Different ratios of solid lipid (stearic acid, beeswax or carnauba wax) and carvacrol were prepared, which were then subjected to thermal treatment to mimic the production of NLCs. The obtained binary mixtures were then characterized by thermogravimetry (TG), differential scanning calorimetry (DSC), small angle X-ray scattering (SAXS) and polarized light microscopy (PLM). The increased concentration of monoterpenoid in the mixtures resulted in an increase in the mass loss recorded by TG, together with a shift of the melting point recorded by DSC to lower temperatures, and the decrease in the enthalpy in comparison to the bulk solid lipids. The miscibility of carvacrol with the melted solid lipids was also confirmed by DSC in the tested concentration range. The increase in carvacrol content in the mixtures resulted in a decrease in the crystallinity of the solid bulks, as shown by SAXS and PLM. The decrease in the crystallinity of lipid matrices is postulated as an advantage to increase the loading capacity of these carriers. Carvacrol may thus be further exploited as liquid lipid in the composition of green NLCs for a range of pharmaceutical applications.This work was funded by the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq/Brazil), the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES/Brazil, FinanceCode 001), by the Portuguese Science and Technology Foundation (FCT/MCT) and European Funds (PRODER/COMPETE) under the projects M-ERA-NET/0004/2015 and UIDB/04469/2020 (strategic fund), co-financed by FEDER, under the Partnership Agreement PT2020.info:eu-repo/semantics/publishedVersio

Increased nitric oxide plasma concentration in dogs with naturally acquired chronic renal disease

ABSTRACT: This study aimed to determine the amount of plasma nitric oxide in clinically stable dogs at different stages of chronic kidney disease (CKD). Five groups of dogs were studied, aged from 4 to 18, comprising of a control group composed of healthy animals (control n=17), group CKD stage 1 (DRC-1, n=12), group CKD stage 2 (CKD-2, n=10) group, CKD stages 3 (CRD-3, n=13) and Group CKD stage 4 (DRC-4, n=10). Dogs with CKD were clinically stable and received no treatment. Two blood samples were collected at 24 hours intervals (repeated measures) to obtain serum and plasma. The serum creatinine values were used to classify dogs as CG, CKD-1, CKD-2, CKD-3 and CKD-4, and were (1.02±0.02mg/dL), (1.07±0.04mg/dL), (1.81±0.03mg/dL), (3.40±0.15mg/dL) and (6.00±0.20mg/dL) respectively. The determination of nitric oxide (NO) was performed by dosing nitrate/nitrite indirectly, and used for measurement of nitrate according to the NO/ozone chemiluminescence. The data were submitted to ANOVA for nonparametric analysis(Kruskal-Wallis) (P<0.05). The concentration of plasmatic NO did not differ significantly among GC (10.81±0.51μM), CKD-1 (15.49±1.97μM) and CKD-2 (19.83±3.31μM) groups. The plasma concentration of CKD-3 (17.02±1.73μM) and CKD-4 (83.56±13.63μM) was significantly higher compared with healthy dogs. In conclusion, the NO plasma concentration can increase in dogs with CKD and become significantly higher in stage 3 and 4 dogs

Análise das políticas públicas: uma proposta metodológica para o estudo no campo da prevenção em Aids Public policies assessment: a methodological proposal for the study in the field of Aids prevention

As políticas públicas são respostas do poder público para problemáticas sociais. Elas são estratégias de grande relevância para o enfrentamento da Aids e desenvolvimento de ações de prevenção da infecção do HIV, pois institucionalizam no setor público de saúde ações sistemáticas para esse fim. Elas se estruturam numa rede de determinantes que delineiam os caminhos a serem trilhados pelo gestor público. Nesse contexto, entram em jogo diversos atores, com diferentes interesses e poder de barganha político-econômica, negociação de concepções de mundo, estratégias de ação e campos de luta por direitos e deveres sociais. É uma disputa de saberes e interesses travada no campo político, permeada por aspectos sócio-culturais e econômicos. Neste sentido, o presente trabalho objetiva uma discussão conceitual sobre esse tema, desenvolvendo a concepção teórica sobre a análise de políticas, enquanto uma metodologia de estudo, compreendendo as categorias: atores, conteúdo, contexto e processo, onde, nessa última, se delimitam especificamente os processos de construção de agenda, formulação e implementação de uma política. Esse quadro teórico é desenvolvido centrando a temática da prevenção da Aids, contextualizada no cenário brasileiro, a partir da qual são elencados alguns entraves das políticas propostas, articulando-as às considerações de especialistas que buscam reorientar as intervenções públicas de prevenção à Aids.<br>Public policies are the response of public power to social issues. They are very relevant strategies to face AIDS and the development of prevention measures concerning HIV infection, for they institutionalize systematic actions in the public health sector with this purpose. They are structured in a network of directives that establish the routes to be followed by public officials. Within this context, different actors are part of the game, with different interests and social and political bargaining powers, world concepts negotiation, actions strategies within the field of social rights and duties. It's a struggle of knowledge and interests in the political ground permeated by social, cultural and economic aspects. Therefore, this paper engages in a concept discussion of the theme, developing a theoretical concept of policies assessment from the viewpoint of a methodological study comprising the following: actors, content, context and process, process circumscribing specific agenda designing processes, policy formulation and implementation. This theoretical scenario is developed focusing on the theme of AIDS prevention, the context being the Brazilian environment from which some of the constraints of policies proposals are listed and linked to specialists'considerations pursuing a reorientation of public interventions concerning AIDS prevention