EVALUATION OF THE SUSPENDING PROPERTIES OF A NEW PLANT GUM IN SULPHAMETOXAZOLE FORMULATIONS

Suspension dosage forms require the use of suspending agents in order to deliver a uniform dose of the active ingredient. The purpose of this study is to investigate the properties of a new plant gum as a cheap and effective natural polymer in the formulation of pharmaceutical suspensions. The gum obtained from the incised trunk of Cedrela odorata (family Meliaceae) was compared with hydroxypropylmethylcellulose and gelatin in Sulphamethoxazole suspension formulations at concentrations of 1.0 – 4.0%w/w. Assessment parameters were sedimentation volume, flow rate, viscosity and the effect of temperature on these parameters. The suspending characteristics of Cedrela gum compared well with that of hydroxypropylmethylcellulose in term of sedimentation volume, flow rate and viscosity and the natural gum could be used as a substitute in pharmaceutical suspensions

Design and evaluation of cedrela gum based microparticles of theophilline.

Objetivo: El objetivo de este estudio fue desarrollar micropartículas de teofilina empleando goma de Cedrela, unas gomas naturales novedosos, como un polímero por pulverización método de secado.Material y Método: Los parámetros del proceso fueron aerosol de secado diferente temperaturas de 110º, 130º y 150ºC. Las micropartículas fueron evaluadas para características tales como tamaño de partícula, la eficiencia de incorporación, análisis térmico, análisis de rayos X de difracción (XRD) e in vitro de liberación del fármaco.Resultados: Las micropartículas eran esféricas con morfología de la superficie distorsionada. El tamaño de partícula oscilaron desde 35,6 hasta 58,0 μm dependiendo de la temperatura de secado por pulverización. Calorimetría diferencial de barrido (DSC) estudios revelaron que la teofilina fue dispersado molecularmente a todas las temperaturas de funcionamiento. La liberación del fármaco desde las micropartículas fue inmediata sin tiempo de retraso con liberación completa obtenida a partir de las micropartículas preparadas en la temperatura más alta.Conclusión: La goma de Cedrela podría servir como un vehículo para la dispersión sólida de fármacos tales como Teofilina por medio de secado por pulverización a una temperatura tan baja como 110ºC. Microesferas obtenidas a esta temperatura eran más pequeños, más de flujo libre y menos susceptible a la aglomeración.Aim: The purpose of this study was to develop microparticles of theophylline employing Cedrela gum, a novel natural gums, as a polymer by spray drying method.Materials and Methods: The process parameters were different spray drying temperatures of 110º, 130º and 150ºC. The microparticles were evaluated for characteristics like particle size, incorporation efficiency, thermal analysis, X-ray diffraction (XRD) analysis and in vitro drug release.Results: The microparticles were spherical with distorted surface morphology. The particle size ranged from 35.6 to 58.0 μm depending on the spray drying temperature. Differential scanning calorimetry (DSC) studies revealed that theophiline was molecularly dispersed at all operating temperatures. The release of drug from the microparticles was immediate with no lag time with complete release obtained from the microparticles prepared at the highest temperature.Conclusion: Cedrela gum could serve as a carrier for solid dispersion of drugs such as Theophilline by means of spray drying at a temperature as low as 110ºC. Microspheres obtained at this temperature were smaller, more free flowing and less susceptible to agglomeration

Powder properties of binary mixtures of chloroquine phosphate with lactose and dicalcium phosphate

A study was conducted on the packing and cohesive properties of chloroquine phosphate in binary mixtures with lactose and dicalcium phosphate powders. The maximum volume reduction due to packing as expressed by the Kawakita constant, a, and the angle of internal flow, &#952;, were the assessment parameters. The individual powders were characterized for their particle size and shape using an optical microscope. Binary mixtures of various proportions of chloroquine phosphate with lactose and dicalcium phosphate powders were prepared. The bulk and tapped densities, angles of repose and internal flow, as well as compressibility index of the materials were determined using appropriate parameters. The calculated and determined values of maximum volume reduction for the binary mixtures were found to differ significantly (P< 0.05), with the Kawakita plot being more reliable in determining the packing properties. Diluent type was found to influence the flow properties of the mixtures, with dicalcium phosphate giving predictable results while mixtures containing lactose were anomalous with respect to flow. The characterization of the packing and cohesive properties of the binary mixtures of chloroquine with lactose and dicalcium phosphate would be useful in the production of powders, tablets, capsules and other drug delivery systems containing these powders with desirable and predictable flow properties.Realizou-se estudo das propriedades de empacotamento e de coesão do fosfato de cloroquina em misturas binárias com lactose e fosfato dicálcico em pó. O volume máximo de redução devido ao empacotamento, segundo expresso pela constante de Kawakita, a, e o ângulo de fluxo interno, &#952;, foram os parâmetros de avaliação. Os pós individuais foram caracterizados por seu tamanho e forma de partículas, utilizando microscópio óptico. Prepararam-se misturas binárias de várias proporções de fosfato de cloroquine e lactose e fosfato dicálcico em pó. As densidades de bulk and tapped, os ângulos de repouso e de fluxo interno e o índice de compressibilidade dos materiais foram determinados utilizando-se parâmetros apropriados. Os valores calculados e determinados do volume máximo de redução para as misturas binárias mostraram-se significativamente diferentes (P< 0,05), sendo o traçado de Kawakita mais confiável na determinação das propriedades de empacotamento. O tipo de diluente influenciou as propriedades de fluxo das misturas com fosfato dicálcico, dando resultados previsíveis, enquanto as misturas contendo lactose mostraram-se anômalas com relação ao fluxo. A caracterização das propriedades de empacotamento e de coesão das misturas binárias de cloroquina com lactose e fosfato dicálcico seria útil na produção de pós, comprimidos, cápsulas e outros sistemas de liberação de fármacos contendo esses pós com propriedade de fluxo desejada e previsível

Influence of binder type and process parameters on the compression properties and microbial survival in diclofenac tablet formulations

The influence of binder type and process parameters on the compression properties and microbial survival in diclofenac tablet formulations were studied using a novel gum from Albizia zygia. Tablets were produced from diclofenac formulations containing corn starch, lactose and dicalcium phosphate. Formulations were analyzed using the Heckel and Kawakita plots. Determination of microbial viability in the formulations was done on the compressed tablets of both contaminated and uncontaminated tablets prepared from formulations. Direct compression imparted a higher plasticity on the materials than the wet granulation method. Tablets produced by wet granulation presented with a higher crushing strength than those produced by the direct compression method. Significantly higher microbial survival (p< 0.05) was obtained in formulations prepared by direct compression. The percent survival of Bacillus subtilis spores decreased with increase in binder concentration. The study showed that Albizia gum is capable of imparting higher plasticity on materials and exhibited a higher reduction of microbial contaminant in the formulations. The direct compression method produced tablets of reduced viability of microbial contaminant.A influência do tipo de ligante e os parâmetros do processo de propriedades de compressão e sobrevivência microbiana em comprimidos de diclofenaco foram estudados utilizando uma nova goma de Albizia zygia. Os comprimidos foram produzidos a partir de formulações de diclofenaco contendo amido de milho, lactose e fosfato bicálcico. As formulações foram analisadas usando os gráficos de Heckel e Kawakita. A determinação da viabilidade microbiana nas formulações foi feita nos comprimidos contaminados e não contaminados preparados a partir de formulações. A compressão direta confere maior plasticidade dos materiais do que o método de granulação úmida. Comprimidos produzidos por granulação úmida apresentaram maior força de esmagamento do que aqueles produzidos pelo método de compressão direta. Observou-se sobrevivência significativamente maior (

Diseño y evaluación de micropartículas de goma de cedrela basados en teofilina

Aim: The purpose of this study was to develop microparticles of theophylline employing Cedrela gum, a novel natural gums, as a polymer by spray drying method. Materials and Methods: The process parameters were different spray drying temperatures of 110º, 130º and 150ºC. The microparticles were evaluated for characteristics like particle size, incorporation efficiency, thermal analysis, X-ray diffraction (XRD) analysis and in vitro drug release. Results: The microparticles were spherical with distorted surface morphology. The particle size ranged from 35.6 to 58.0 μm depending on the spray drying temperature. Differential scanning calorimetry (DSC) studies revealed that theophiline was molecularly dispersed at all operating temperatures. The release of drug from the microparticles was immediate with no lag time with complete release obtained from the microparticles prepared at the highest temperature. Conclusion: Cedrela gum could serve as a carrier for solid dispersion of drugs such as Theophilline by means of spray drying at a temperature as low as 110ºC. Microspheres obtained at this temperature were smaller, more free flowing and less susceptible to agglomeration.Objetivo: El objetivo de este estudio fue desarrollar micropartículas de teofilina empleando goma de Cedrela, unas gomas naturales novedosos, como un polímero por pulverización método de secado. Material y Método: Los parámetros del proceso fueron aerosol de secado diferente temperaturas de 110º, 130º y 150ºC. Las micropartículas fueron evaluadas para características tales como tamaño de partícula, la eficiencia de incorporación, análisis térmico, análisis de rayos X de difracción (XRD) e in vitro de liberación del fármaco. Resultados: Las micropartículas eran esféricas con morfología de la superficie distorsionada. El tamaño de partícula oscilaron desde 35,6 hasta 58,0 μm dependiendo de la temperatura de secado por pulverización. Calorimetría diferencial de barrido (DSC) estudios revelaron que la teofilina fue dispersado molecularmente a todas las temperaturas de funcionamiento. La liberación del fármaco desde las micropartículas fue inmediata sin tiempo de retraso con liberación completa obtenida a partir de las micropartículas preparadas en la temperatura más alta. Conclusión: La goma de Cedrela podría servir como un vehículo para la dispersión sólida de fármacos tales como Teofilina por medio de secado por pulverización a una temperatura tan baja como 110ºC. Microesferas obtenidas a esta temperatura eran más pequeños, más de flujo libre y menos susceptible a la aglomeración.Financiado por la Universidad Nacional de La Pampa, Argentina.This work was made possible by the research fellowship awarded to M. A. Odeniyi by the Matsumae International Foundation, Japan at the Gifu Pharmaceutical University, Gifu, Japan

Evaluation of Cedrela gum as a binder and bioadhesive component in ibuprofen tablet formulations

The compressional, mechanical and bioadhesive properties of tablet formulations incorporating a new gum obtained from the incised trunk of the Cedrela odorata tree were evaluated and compared with those containing hydroxypropylmethylcellulose (HPMC). Compressional properties were evaluated using Hausner's ratio, Carr's Index, the angle of repose, and Heckel, Kawakita and Gurnham plots. Ibuprofen tablets were prepared using the wet granulation method. Bioadhesive studies were carried out using the rotating cylinder method in either phosphate buffer pH 6.8 or 0.1 M hydrochloric acid media. The gum is a low viscosity polymer (48 cPs), and Fourier transform infrared spectroscopy revealed the presence of a hydroxyl group. Py and Pk values, which are measures of plasticity, showed the gum to be significantly (p<0.05) more plastic than HPMC, and plasticity increased with polymer concentration. All tablet formulations were non-friable (<1.0%), and the formulations containing the gum had a higher crushing strength (130.95 N) than those containing HPMC (117.85 N) at 2.0% w/w binder. Formulations incorporating the gum were non-disintegrating and had a significantly longer drug release time than those containing HPMC. At the highest binder concentration, Cedrela gum formulations adhered to incised pig ileum longer than those containing HPMC. Cedrela gum exhibited better compressive, flow and binding properties than HPMC and is suitable as a bioadhesive and for sustained release of drugs.<br>Propriedades de compressão, mecânicas e de formulações de comprimidos bioadesivos, que incorporam nova goma de mascar obtidas a partir de incisão de tronco da árvore de Cedrela odorata, foram avaliadas e comparadas com aquelas contendo hidroxipropilmetilcelulose (HPMC). Propriedades de compressão foram avaliadas usando a razão de Hausner, índice de Carr, ângulo de repouso e os gráficos de Heckel, Kawakita e Gurnham. Prepararam-se comprimidos de ibuprofeno utilizando o método de granulação a úmido. Realizaram-se estudos de bioadesividade utilizando o método de cilindro rotativo em tampão fosfato pH 6,8, ou meio ácido com 0,1 M de ácido clorídrico. A goma é um polímero de baixa viscosidade (48 cPs) e a espectroscopia no infravermelho por Transformada de Fourier (FTIR) revelou a presença de um grupo hidroxila. Valores de Py e Pk, que são medidas de plasticidade, mostraram que a goma é significativamente (p <0,05) mais plástica do que HPMC e que a plasticidade aumenta com a concentração de polímero. Todas as formulações de comprimidos mostraram-se não-friáveis (<1,0%) e aquelas contendo a goma apresentaram maior resistência ao esmagamento (130.95N) do que aquelas contendo HPMC (117.85N) em 2,0% (p/p) do ligante. As formulações que incorporaram a goma eram não-desintegrantes e apesentaram tempo de liberação significativamente maior do que aquelas contendo HPMC. As formulações de goma de Cedrela aderiram à incisão de íleo de porco por tempo maior do que aquelas contendo HPMC com a maior concentração de ligante. A goma Cedrela apresentou melhor fluxo, compressão e propriedades de ligação do que HPMC e é adequada como bioadesivo e para a liberação sustentada de fármacos

Effect of thermal and chemical modifications on the mechanical and release properties of paracetamol tablet formulations containing corn, cassava and sweet potato starches as filler-binders

AbstractObjectiveTo investigate the effects of acetylation and pregelatinization of cassava and sweet potato starches on the mechanical and release properties of directly compressed paracetamol tablet formulations in comparison with official corn starch.MethodsThe native starches were modified by acetylation and pregelatinization. The tablets were assessed using friability (Fr), crushing strength (Cs), disintegration time (Dt) and dissolution parameters.ResultsStarch acetylation produced paracetamol tablets that were stronger and had the best balance of mechanical and disintegration properties, while pregelatinization produced tablets that were more friable but had a better overall strength in relation to disintegration than formulations made from natural starches. Correlations mainly existed between Dt and the dissolution parameters t80, t2 and k1 in the formulations.ConclusionsModification of the experimental starches improved the mechanical and release properties of directly compressed paracetamol tablet formulations. Thus, they can be developed for use as pharmaceutical excipients in specific formulations