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

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

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

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 (

Solid state characterization and rheological properties of native and modified Bambara groundnut (Vigna subterranean) starches

This study was designed to determine the suitability of native, pregelatinized and carboxymethylated Vigna subterranean (Bambara nut) starches for pharmaceutical applications, through their characterization by means of physicochemical, rheological, thermal, morphological and instrumental spectroscopic methods. The native starch was extracted from Bambara nut, after which it was used to prepare both pregelatinized and carboxymethylated forms. Microscopy revealed increased in granular size on modification. Both pregelatinized and carboxymethylated Bambara starches had better flow properties and swellability compared to the native starch. Native Bambara starch had greater tendency to retrogradation, was more sensitive to heat and heat change, these were alleviated by both pregelatinization and carboxymethylation. DSC confirmed that carboxymethylated Bambara starch was the most thermally stable starch. Presence of functional groups and crystallinity were established by FTIR and XRD, respectively. Native and modified Bambara starches can be used as locally and readily available alternative excipients in pharmaceutical formulations

Comparative analysis of eight brands of sulfadoxine-pyrimethamine tablets

Purpose: The aim of the present study is to investigate the physicochemical equivalence of eight brands of tablets containing sulfadoxine-pyrimethamine (antimalarial drug combination) sourced from different retail Pharmacy outlets in the Nigerian market. Method: The quality and physicochemical equivalence of eight different brands of sulfadoxine-pyrimethamine combination tablets were assessed. The assessment included the evaluation of uniformity of weight, friability, crushing strength, disintegration and dissolution tests as well as chemical assay of the tablets. Results: All the eight brands of the tablets passed the British Pharmacopoeia (BP) standards for uniformity of weight, disintegration and crushing strength. Three of the eight brands failed the friability test. One of the brands did not comply with the standard assay of content of active ingredients while another brand did not comply with the USP specifications for dissolution test for sulfadoxine-pyrimethamine tablets. There were no significant differences in the amounts of pyrimethamine and sulfadoxine released from the different brands (P>0.05). Conclusion: Only three brands (registered by NAFDAC) out of the eight brands of sulfadoxine-pyrimethamine tablets that were analysed passed all the BP quality specifications and were physically and chemically equivalent. This study highlights the need for constant market monitoring of new products to ascertain their equivalency to the innovator product. Keywords: Chemical equivalence, comparative study, pyrimethamine-sulfadoxine tablets Tropical Journal of Pharmaceutical Research 2003; 2(1): 161-16

Comparison of sensitivity of bacteria isolated in odontogenic infections to ceftriaxone and amoxicillin-clavulanate

Background: Odontogenic infections is a cause of mortality and morbidity in maxillofacial patients. This is largely due to resistance of organisms to antibiotics prescribed.Objectives: To isolate organisms involved in odontogenic infections and compare the sensitivity of the organisms to Ceftriaxone and Amoxicillin-Clavulanate.Methods: The causative organisms and antibiotic sensitivity were determined by the following steps: Aspiration of pus done with needle, sample of pus or exudate collected using sterile swab if aspiration was unsuccessful and specimen were placed in transport media (thioglycolatebroth) and sent immediately to microbiology laboratory for culture of organisms and antibiotic sensitivity.Results: Out of a total 55 samples taken for bacteriology, 42 (76.4%) yielded positive culture for bacteria. A total number of 21 bacteria species were identified from the positive cultures. Overall, 52% of isolated organisms were sensitive to amoxicillin-clavulanate, 70% were sensitive to Ceftriaxone while 24% were resistant to both antibiotics (Table 3). Ceftriaxone was statistically significantly more potent in inhibiting bacteria growth than amoxicillin-clavulanate (P =0.009).Keywords: Sensitivity of bacteria, odontogenic infections, ceftriaxone, amoxicillin-clavulanate

The effect of thermal and chemical modifications of excipients on the compressional properties of paracetamol tablet formulations including maize, cassava and sweet potato starches as filler-binders

The effects of thermal and chemical modifications on the properties of directly compressed paracetamol tablets containing cassava and sweet potato starches were compared with official maize starch. Fresh tubers of the cassava plant, Manihot esculenta Crantz (family Euphorbiaceae) and the sweet potato plant Ipomoea batatas L. Lam (family Convolvulaceae) were obtained and the acetylated and pregelatinized forms of these were prepared using Maize Starch BP as the standard. Paracetamol tablet formulations (500mg) were prepared by direct compression including the starches at various amounts. The compressional properties of the tablets were evaluated using the Heckel, Kawakita and Gurnham equations. Modifications of the starches decreased the Pk (an inverse measure of plasticity) values in the paracetamol formulations at low starch concentrations (10.0% to 25.0%), indicating an increase in the total amount of plastic flow. The Pk values increased at higher starch concentrations (> 50.0%). Tablets containing maize starch showed higher c values when using the Gurnham equation suggesting greater densification. The thermal and chemical modification of the experimental starches improved the compressional properties of the directly compressed paracetamol tablet suggesting that they could be developed for use as pharmaceutical excipients