If you open the hard gelatin capsule apart, you can find small flowing spherical or semispherical particles, these are called pellets, another type of solid dosage form used extensively, and these have several advantages. Let us see the types of pelletization techniques in this article.

Pellets are 0.5 – 2.0 mm in diameter and are formulated into either sustained release or immediate release They can also be formulated by coating as a site-specific release. These can be compressed into tablets named MUPS and pellets are normally filled in hard gelatin capsules.

Different Techniques for Pellets Formulation

• Extrusion Spheronization technique
• Powder layering
• Solution or Suspension Layering
• Melt Pelletization Technique
• Cryopelletization
• Balling
• Direct Pelletization Technique
• Spray drying and spray congealing

The above listed are some of the techniques used in pellet making in pharma and now we are going to learn the most used techniques

• Powder layering – This is one of the most used techniques where a solid core is layered with a powder mix. The powder is a mixture of drugs and other excipients. This technique can be done either manually using a coating pan where the operator continuously loads the drug-excipient mixture into the rotating pan slowly until the drug layer forms on the core pellets. This is achieved by the use of a binder solution. Fluid bed coater can also be used for this technique.

• Extrusion – Spheronization technique: In this technique, we first make extrudes from the wet mass using an extruder. Here the wet mass is prepared by mixing all the powders and made into a wet mass using a suitable solvent. Then the extrudes are dried and placed in a spheronizer to get spherical pellets or near spherical pellets.

• Solution – Suspension layering: This is the most widely used pellet-making technique using the Wurster coating technique. Here for this technique, we need a fluid bed processor with bottom spray. Here pellets are loaded into the bowl of the fluid bed coater and fixed to the body of the FBC and solution is sent through the nozzle fixed at the bottom of the bowl, we can also fix the height of the gun. Here in FBC, air is blown upward through the bed, putting the loaded core pellets in the fluidized state within the chamber.  The core pellets pass through the solution sprayed upward from the nozzle repeatedly, leading to the coating of the core pellets with drug or other layers, depending upon the stage of the process after this process drying is done for some time and allowed to cool down. Here in this technique pellets are coated uniformly