A comprehensive review on process and engineering aspects of pharmaceutical wet granulation

- Granulators and their design.
- Granule attributes and their characterization.
- Process control and optimization.
- Modelling and simulation.
- Kinetics and scale up.

Wet granulation is a very important unit operation that finds applications in many industries mainly pharmaceutical and chemical industries. Various granulation technologies in batch and continuous modes were employed viz., high shear granulators, fluid bed granulators, twin screw granulators and the novel ones like foam granulators, steam granulators, dry granulators etc. In this review, various aspects of pharmaceutical granulation like technologies, characterization tools, process control, modelling and simulation, kinetics and scale up have been thoroughly analysed and discussed in terms of development trends and future challenges and prospects. The critical role played by various off line and inline characterization tools was highlighted along with their applications. Studies from PBM, DEM to hybrid models, CFD and ANN based models were presented in terms of their performance and challenges. Kinetic studies to understand the rate and influencing parameters of various steps involved in granulation process with controlling regimes were discussed along with the models used. The scale-up, a major challenge in granulation was also discussed in terms of the methodology and efficiency in retaining the granule attributes with proper control of process parameters was also presented. Process control protocols employed in the wet granulation process was discussed along with the relations of different granule and tablet attributes to process and design parameters. The future challenges and prospects in the above mentioned aspects were listed for prospective researchers.

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