Granulate, particle size

Traditionally, active carbons are made in particulate form, either as powders (particle size < 100 pm, with an average diameter of -20 pm) or granules (particle size in the range 100 pm to several mm). The main precursor materials for particulate active carbons, PAC, are wood, coal, lignite, nutshells especially from coconuts, and peat. In 1985, 360 kt of such precursors (including 36 % wood and 28 % coal) were used to make active carbons [10], of which nearly 80 % were used in liquid-phase applications, with the rest being used in gas-phase applications. Important factors in the selection of a precursor material for an active carbon include availability and cost, carbon yield and inorganic (mainly mineral) matter content, and ease of activation. 

Granulate, particle-size material specifically manufactured or produced from basic product off-cuts. Supplied by most manufacturers and used for packing or pouring into irregular-shaped enclosures. 

Once the analytical method is validated for accuracy at the laboratory scale, it can be used to obtain extensive information on process performance (blend homogeneity, granulation particle size distribution, and moisture content) under various conditions (blender speed, mixing time, drying air temperature, humidity, volume, etc.). Statistical models can then be used to relate the observable variables to other performance attributes (e.g., tablet hardness, content uniformity, and dissolution) in order to determine ranges of measured values that are predictive of acceptable performance. 

Granulation particle size did not impact the release rate. In addition, tableting at various compression forces had no significant impact on the release rate of the tablets. This knowledge that variability in tablet manufacture resulted in a uniform sustained release dosage form provided an advantage for further process optimization and scale-up, as shown in Figure 23. 

Granulation particle size distribution An extremely important parameter that can affect tablet compressibility, hardness, thickness, disintegration, dissolution, weight variation, and content uniformity. This parameter, which can be done by sieve analysis, should be monitored throughout the tablet validation process. 

Evaluate granulation particle size distribution Manufacturability Particle size analysis or powder flow assessment Powder flow... 

Achieve a homogeneously distributed API within the range of granulation particle sizes Quality Granulation sieve cut potency Tablet content uniformity... 

Evaluation of Granulation Particle Size Distribution and Density... 

Similarly, the granulation particle size distribution of Drug B shows a significant increase in the weight percent of material remaining in the 20, 40, and 60 mesh screen... 

Figure 6.6 Comparison of initial blend and final granulation particle size distribution— Drugs A and B.

In contrast, increasing the gap width between the dry granulator rollers decreases the density of the compacted ribbon or briquette (also possible when other factors, such as feed rate or roll force, are changed). This reduced densification process results in a weaker binding of API to carrier excipients, and reduced overall granulation particle size distribution and increased bypass. 

In the storage stability monitoring program, dispersability of the granules, particle size (before and after shipping and storage) and particle hardness should be evaluated. In addition, chemical stability must be evaluated. 

Fig. 6 Influence of the granule particle size on the theophylline release properties of the tablets containing hot-melt extruded granules (n = 3). Tablets 20% extruded granules (Formula 3 25% theophylline, 2% PEG, and 73% PVAc), 79.5% Avicel PH200, and 0.5% magnesium stearate ( ) Less than 125 pm (i) 180-212 pm (a) 300 25 pm (O) 500-600 pm. (From Ref. l)...

A minimum amount of material recirculation is necessary to provide steady flow and fill. Too much recirculation can result in material back-up and reduction in the granulation particle size. The recirculation channel must be free of obstructions (i.e., broken tablets). 

The composition of the sample has a dramatic influence on extraction. Solid samples can differ significantly in their physico-chemical properties, the type of compounds they contain and their degree of granulation (particle size). These factors affect sorption and retention of analytes. 

Fig. 5 illustrates the granule particle size distribution as a function of gap size between rotor and stator. As can be seen, the average particle size D(50) is approximately equal to the gap size, and the particle size span (ca. 0.5) is very low and independent of gap size. Typically, the concentration of the binder is 25wt%. In all of the known agglomeration and microencapsulation techniques, the concentration of... 

Steiner G, Patel M, Carstensen JT. Effeet of milling on granulation particle—size distribution. J Pharm Sci 1974 63 1395-1398. 

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