Abstract Flaxseed (Linum usitatissimum L.) is the seed of a multipurpose plant of pharmaceutical interest, as its mucilage can be used as a natural matrix to develop extended-release dosage forms and potentially replace synthetic polymers. In this study, a 3² factorial design with two replicates of the central point was applied to optimize the development of extended-release granules of metformin HCl. The total fiber content of the mucilage as well as the friability and dissolution of the formulations were evaluated. The lyophilized mucilage presented a high total fiber content (42.63%), which suggests a high efficiency extraction process. Higher concentrations of the mucilage and metformin HCl yielded less friable granules. In addition, lower concentrations of metformin HCl and higher concentrations of the mucilage resulted in slower drug release during the dissolution assays. The release kinetics for most formulations were better represented by the Hixson-Crowell model, while formulations containing a higher concentration of the mucilage were represented by the Korsmeyer-Peppas model. Nonetheless, five formulations showed a longer release than the reference HPMC formulation. More desirable results were obtained with a higher concentration of the mucilage (13-18%) and a lower concentration of metformin (40%).

Abstract This study aimed to prepare hydrogel containing Cymbopogon citratus (DC.) Stapf, Poaceae, volatile oil encapsulated in poly (d,l-lactide-co-glycolide) nanoparticles and to evaluate its in vitro anti-herpetic activity. Polymeric nanoparticles were prepared by solvent emulsification-diffusion method and incorporated in carbomer hydrogels. In vitro release profiles for the nanogel, loaded nanoparticles and hydrogel containing free oil were evaluated by dialysis. Inhibitory activities against Herpes simplex for the formulations were investigated in Vero cells. Hydrogel was developed using nanoparticles with mean diameter of 217.1 nm and negative Zeta potential (−20.5 mV). Volatile oil release profile showed a biphasic pattern with an initial faster release and subsequent sustained phase in all formulations. Nanogel strongly inhibited virus in a non-cytotoxic concentration, 42.16 times lower than free oil, 8.76 and 2.23 times than loaded nanoparticles and hydrogel containing free oil, respectively. These results highlight the potential of nanogel to protect oil against volatilization, control release and improve its anti-herpetic activity.

O objetivo deste trabalho foi melhorar as características de fluxo do fluconazol com o emprego da granulação úmida e estudar o efeito desse processo na dissolução do fármaco em cápsulas e comprimidos. O fluconazol foi submetido ao processo de granulação úmida num granulador de alta velocidade empregando Plasdone K29/32 e K90. Foram determinadas as propriedades de fluxo dos grânulos e obtidos os perfis de dissolução de cápsulas e comprimidos obtidos com os granulados em estudo. Os grânulos de fluconazol apresentaram melhores características de fluxo após o processamento, demonstradas por meio das determinações do ângulo de repouso e do índice de compressibilidade, comparativamente à matéria-prima. Adicionalmente, observou-se que o processo de granulação melhorou a eficiência de dissolução (ED) do fluconazol nos comprimidos e cápsulas.

The aim of this work was to improve fluconazole flowability by wet granulation and to study the effect of granulation on drug dissolution from tablets and capsules. Fluconazole was submitted to a process of wet granulation in a high-speed granulator using Plasdone® K29/32 or K90. Flow properties of granules and dissolution profiles for tablets and capsules produced with them were determined. Fluconazole granules demonstrated better flowability, calculated by angle of repose and compressibility index data, compared with powder. Additionally, it was observed that the granulation process improved the dissolution efficiency (ED) of fluconazole from tablets and capsules, which could also suggest an increase in bioavailability. Higher dissolution efficiencies were achieved with Plasdone® K29/32.

Este trabalho avaliou a influência da concentração de amido de milho nas características físicas e na liberação in vitro de paracetamol a partir de comprimidos. Os granulados foram analisados quanto à granulometria e densidades aparentes bruta e compactada e os comprimidos quanto ao peso médio, espessura, dureza, friabilidade, tempo de desintegração. Os comprimidos foram preparados a partir de granulados obtidos por granulação a úmido, utilizando cozimento de amido a 10% como agente granulante, segundo três formulações. Embora os comprimidos obtidos tenham apresentado características dentro dos limites farmacopéicos, os resultados indicam que variações da concentração de amido provocam diferenças nos diversos parâmetros físicos estudados. Concentração mais alta de amido em pó dá origem, provavelmente, à interação entre os componentes da fórmula, interferindo na liberação in vitro do fármaco. Isto demonstra a importância de se otimizar a concentração dos adjuvantes numa formulação de comprimidos, pois, embora uma pequena variação nesta concentração não exerça efeito significativo no tempo de desintegração, a quantidade de fármaco liberado pode ser substancialmente alterada.

This paper describes the influence of maize starch concentration on the physical characteristics and on in vitro release of acetaminophen from compressed tablets. The granulates were analyzed in relation to size distribution and bulk and compacted densities, and the tablets in relation to mean weight, thickness, hardness, friability and disintegration time. The tablets were prepared from granulates made by wet granulation with 10% starch paste in three formulations. Although the tablets obtained have presented characteristics in accordance with pharmacopeial limits, the results indicate that variations on starch concentration cause differences on the several physical parameters studied. Higher starch concentration probably originates an interaction among the ingredients of the formulations, interfering on the in vitro drug release.This fact demonstrates the importance in optimizing the concentration of the adjutants in a tablet formulation, because, although a short variation in this concentration has no significant effect on disintegration time, the amount of released drug can be substantially modified.