Granulation variables equipment

For excellent classical review of the wet granulation process, equipment and variables, and measurement instruments available in the field, see papers by Holm et These papers have become a standard refer-... 

Compared to conventional spray processing, FBT can shorten processing times by reducing water requirements. It can improve reproducibility through more uniform binder distribution. Moreover, it eliminates spray nozzles and their many variables in granulation processing equipment. Foam processing also offers better end-point determinations and reduced equipment clean-up time. 

Irrespective of the method used to produce the granules and the consequent batch size, a signiflcant factor in scale-up is the increase in drying capacity in larger equipment. The heat delivered to the bed of fluidizing granules comes from a combination of inlet air temperature and volume, and, to a lesser extent, inlet air dew point. As previously mentioned, the process air volume is also responsible for fluidization behavior, and this will be the first variable to be considered. 

In the milling, blending, granulating and or drying processes, the operating principles of the equipment employed should be defined, and the variables determined. The impact and mechanism of measurement on in-process variables should be defined. Time, temperature, work input of equipment, blend/ granulation volume, and granulating rate should be determined. 

The variability of sieve cut potencies for Drugs A and B as a function of various roll force levels and dry granulation equipment manufacturers is tabulated in Table 6.14. The change in equipment type had no significant affect on sieve cut potency variability for Drug B. The increased roll force using the same equipment type did impact the variability of sieve cut potencies for Drug A in terms of RSD. 

Some of the operating variables are characteristic of the equipment (i.c., pressure, rhythm, and frequency of vibration to accelerate the flow of powder into the die), while others depend on the charge and, for a given powder, on the granulometry, the kind and concentration of binders, and the lubricants. The ratio of the diameter of the powder particles to that of the final granules should fall between 1/20 and 1/50. 

Sheskey, P. J., and Hendren, J. (1999),The effects of roll compaction equipment variables, granulation technique, and HPMC polymer level on a controhed-release matrix model drug formulation, Pharm. Technol., 23, 90, 92, 94, 96, 98,100,102,104,106. 

Critical variables may be characteristic of the materials and/or the process. Materials properties have already been discussed briefly and of course the equipment variables for the unit operations will depend upon differences in the raw materials. However, there are general relationships between the roller compaction process variables and the properties of the resulting ribbons and granules that can aid in process design. 

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