ABSTRACT
Objetivo: incorporar la indometacina en sistemas autoemulsionables de liberación con la finalidad de aumentar su solubilidad en medio acuoso, la velocidad de disolución y permeación in vitro. Metodología: se llevaron a cabo ensayos de solubilidad al equilibrio para preparar formulaciones con los excipientes, en los cuales la indome-tacina presentó mayor incremento de solubilidad; los sistemas fueron caracterizados por medio del tiempo de autoemulsificación, estabilidad física, tamaño de partícula, potencial zeta, perfiles de disolución y permeación a través de membrana sintética. Resultados: el diseño experimental de los sistemas autoemulsionables de liberación permitió crear formulaciones que aumentaron la solubilidad de la indometacina en un orden de 105 veces con respecto a la solubilidad acuosa. Las formulaciones que resultaron viables presentaron tiempos de autoemulsificación menores que 60 segundos, además, las distribuciones de tamaño de partícula de las dispersiones fueron inferiores a los 300 nm, presentó índices de polidispersión inferiores a 0,3 y valores de potencial zeta menores de -25 mV. Los perfiles de disolución mostraron que las formulaciones cumplen con un valor de factor de similitud mayor que 50, además, la permeabilidad a través de membrana sintética es mayor para las formulaciones autoemulsionables que el producto de referencia. Conclusiones: la formulación de indometacina en sistemas autoemulsionables de liberación incrementa la solubilidad en medio acuoso, aumenta la disolución y liberación. Estos resultados sugieren que la administración oral de indometacina incorporada en sistemas autoe-mulsionables puede acelerar el inicio del efecto farmacológico.
SUMMARY Aim: To load indomethacin into self-emulsifying delivery systems in order to increase, water-solubility, rate dissolution and in vitro permeation. Methodology: Equilibrium solubility tests were carried out to prepare formulations with the excipients, in which indomethacin presented a greater increase in solubility; the systems were characterized by self-emulsification time, physical stability, particle size, zeta potential, dissolution profiles and permeation through synthetic membrane. Results: The experimental design of self-emulsifying delivery systems allowed to create formulations that increase the solubility of indomethacin in an order of 105 times with respect to the aqueous solubility. The feasible formulations presented autoemulsification times less than 60 seconds, in addition, the particle size distributions of the dispersions were less than 300 nm, with polydispersity index smaller than 0.3, and zeta potential values lower than -25 mV. The dissolution profiles showed that the formulations comply with a similarity factor value greater than 50, in addition, the permeability through a synthetic membrane is higher for the self-emulsifying formulations than the reference product. Conclusion: The formulation of indomethacin into self-emulsifying delivery systems enhances the solubility in aqueous medium, increases dissolution and accelerate release. These results suggest that the oral administration of indomethacin incorporated into self-emulsifying delivery systems can accelerate the onset of the pharmacological effect.
Objetivo: incorporar a indometacina em sistemas de liberação autoemulsificantes a fim de aumentar sua solubilidade em meio aquoso, a taxa de dissolução e permeação in vitro. Metodologia: foram realizados testes de solubilidade de equilíbrio para preparar formulações com os excipientes, nas quais a indometacina apresentou maior aumento na solubilidade; os sistemas foram caracterizados quanto ao tempo de autoemulsificação, estabilidade física, tamanho de partícula, potencial zeta, perfis de dissolução e permeação através de membrana sintética. Resultados: o desenho experimental dos sistemas de liberação autoemulsificantes permitiu a criação de formulações que aumentaram a solubilidade da indometacina na ordem de 105 vezes em relação à solubilidade aquosa. As formulações que se mostraram viáveis apresentaram tempos de autoemulsificação inferiores a 60 segundos, além disso, as distribuições granulométricas das dispersões foram inferiores a 300 nm, apresentaram índices de polidispersidade inferiores a 0,3 e valores de potencial zeta inferiores a -25 mV. Os perfis de dissolução mostraram que as formulações atendem a um valor de fator de similaridade maior que 50, além disso, a permeabilidade através da membrana sintética é maior para as formulações autoemulsionantes do que para o produto de referência. Conclusões: a formulação de indometacina em sistemas de liberação autoemulsificantes aumenta a solubilidade em meio aquoso, aumenta a dissolução e a liberação. Esses resultados sugerem que a administração oral de indometacina incorporada em sistemas autoemulsificantes pode acelerar o início do efeito farmacológico.
ABSTRACT
The field of SMEDDS is designed to enhance bioavailability of poorly-water soluble compounds. Yet, these systems have the capacity to solubilize aqueous-based materials within its lipid matrix as L2 phase (W/O microemulsion). This characteristic is utilized in this investigation to incorporate aqueous flavors within oil vehicle as an approach to mask bitter taste of drugs. Miscibility profiles and self-micro-emulsifying regions for various lipid composites were screened by constructing ternary phase diagrams using different types of oil, cosurfactant and surfactant. Solubility of bitter taste model drug was measured in various optimized vehicles. Dynamic equilibrium phase studies were performed and phase boundaries were determined for the lipid-aqueous flavors-water systems. Self-micro-emulsifying system comprising Crodamol GTCC/ Glycerox 767HC /Croduret 40 ss at ratios of {0/80/20}, {6/54/40} or {10/40/50} have shown capacity to solubilize, aqueous-based materials including; strawberry flavor, sucrose and citric acid as L2 phase. Phase behavior study has revealed that clear dispersions can be obtained at all dilutions with water. Potential flavored self-microemulsifying lipid formulations representing type III lipid class system were developed. Aqueous flavors loaded into these vehicles can be used to mask bitter tastes in oral pharmaceuticals.
ABSTRACT
The aim of our study was to compare the nephrotoxic effects of liposomal amphotericin B (Ambisome) and amphotericin B lipid complex (Abelcet) on rat kidneys at short (14 days) and long term (28 days) treatment applications. Thirty-six male Wistar rats were included and divided into six groups (n=6). Groups 1 and 4 are composed as control groups by administrating intraperitoneal (ip) 0, 9 molar Serum physiologic for a period of 14 and 28 days respectively. Group 2 and 3 are treated with 5 mg/kg Ambisome and 5 mg/kg Abelcet for 14 days respectively, group 5 and 6 are treated with same agents for 28 days respectively. Then, the rats were transcardially perfused, samples were taken from cortex and medulla regions of kidneys. The micrographs of group 1 and 4 were seen as normal. For short term treatment, some morphological changes were seen in proximal tubule cells in group 3 whereas in group 2 the graphs were observed as normal. However, after long term drug using in group 5 and 6 there were vacuolization, increased lysosomal structures and deep basal folding's into tubular cells lumen. These experiments establish that renal damage were seen in short and long term use of Abelcet and long term use of Ambisome.
El objetivo de nuestro estudio fue comparar los efectos nefrotóxicos de la anfotericina B liposomal (AmBisome) y anfotericina B en complejo lipídico (Abelcet) sobre riñones de ratas, en el tratamiento de aplicación a corto (14 días) y largo plazo (28 días). Fueron incluidas en el estudio 36 ratas Wistar machos, divididas en seis grupos (n = 6). Los Grupos 1 y 4 fueron grupos de control mediante la administración intraperitoneal (ip) de 0, 9 molar de suero fisiológico durante un periodo de 14 y 28 días respectivamente. Los Grupos 2 y 3 fueron tratados con 5 mg/kg de ambisome y 5 mg/kg abelcet durante 14 días respectivamente, y finalmente los grupos Grupos 5 y 6 tratados con los mismos agentes durante 28 días, respectivamente. Luego, las ratas fueron perfundidas vía transcardíaca, y se tomaron muestras de la corteza y la médula renal. Las micrografías de los grupos 1 y 4 se observaron normal. En el tratamiento a corto plazo, algunos cambios morfológicos se observaron en las células del túbulo proximal en el grupo 3, mientras que en el grupo 2 los gráficos se observaron normales. Sin embargo, después de utilizar la droga a largo plazo en los grupos 5 y 6 hubo vacuolización, aumento de las estructuras lisosomales y un profundo plegamiento basal de las células del lumen tubular. Estos experimentos establecen que el daño renal se produce en el uso a corto y largo plazo de Abelcet, y largo plazo de Ambisome.
Subject(s)
Animals , Rats , Amphotericin B/toxicity , Liposomes/toxicity , Kidney/ultrastructure , Amphotericin B/administration & dosage , Liposomes/administration & dosage , Rats, Wistar , Kidney , Time FactorsABSTRACT
Currently available antifungal agents for the treatment of systemic fungal infections in Japan are smaller in number than those in the United States and Europe and probably in Korea. Therefore, the development of novel antifungal drugs for clinical use, including new formulations of approved agents, with advantages over and/or complimentary to existing agents is particularly needed in Japan. In this review, I have described historical perspectives of existing systemic antifungal agents and provided a brief overview of the current status of clinical development of several different categories of new drugs as follows: (1) liposomal amphotericin B; (2) itraconazole-hydroxypropyl-beta-cyclodextrin complexes; (3) phosphatyl fluconazole (phosfluconazole) ; (4) voriconazole; and (5) micafungin (FK463). At this moment, micafungin, a member of echinocandins attracts the greatest attention of Japanese medical mycologists because it has just been introduced into the clinic and has unique chemical and biological characteristics distinct from any other existing class of antifungal drugs. Micafungin, as well as other new drugs under clinical development, should constitute effective new options for the management of a variety of systemic fungal infections.