Granule properties friability

Binder Different binders have different binding properties and the concentration of an individual binder may have to be changed to obtain similar binding of primary particles. Thus, the type of binder, and binder content in the formulation and concentration of the binder have major influence on granule properties. These properties include friability, flow, bulk density, porosity, and size distribution. 

The bonding forces in a dry aggregate are important to granulation properties such as granule integrity, flow-ability, friability, density, compressibility, and size for down-stream manufacturing process steps. Rumpf and coworkers described the bonding mechanisms... 

A specific example of granulation properties in the combination vacuum/micro-wave technology versus forced air drying is reviewed in Ref. 38. The article describes the influence of these drying methods on attributes such as specific surface area, porosity, friability, hardness and morphology. 

When evaluating the effect of binder concentration on a number of tablet properties, surface area measurements were used to investigate the bond strength of the binder with the other particles [18]. A steady reduction in the surface area of the granules with increasing binder concentration indicated that the binder had covered or penetrated the particles, with the formation of particle-binder bonds. This was related to friability, and the increased bond strength was related to the decreased surface areas. 

FIGURE 2.45 Plots of the physical properties (crushing strength, disintegration time, and friability) of the coprocessed chitin-mannitol mixtures prepared by different granulation techniques versus the amount of magnesium stearate added. 

However, it has been possible to demonstrate in the production of caffeine tablets, that povidone K 25 increases the particle size and bulk density of the granulate, giving it better flow properties and reducing the friability of the tablets [400]. 

The objective was to obtain tablets of low friability and satisfactory hardness. Good compression properties were also needed, that is a high transmission ratio and also a high cohesion index (see below). A granulate with at least 20% fine particles was also considered desirable, for the powder to flow correctly. 

The mixtures were granulated and tableted, and the usual properties of granulates and tablets were measured - flow, friability, hardness, disintegration. They are listed in table 9.11. 

PVP Concentration. The effect of binder concentration on the properties of granules and tablets prepared by roller compaction is dependent on other processing parameters including feed rate, roll pressure, and speed. Increasing the binder level increases tablet hardness and decreases their friability due to the... 

Millili and Schwartz demonstrated the effect of granulating with water and ethanol at various ratios. The physical properties of the spheres changed significantly as the ratio of the two fluids was varied. Spheres could not be formed with absolute ethanol but were possible with 5 95 waterlethanol. An increase in the water fraction resulted in a decrease in porosity, friability, dissolution, and compressibility and an increase in density. The porosity of spheres granulated with 95% ethanol was 54%... 

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