“Pellets Technology: Special focus on Wruster Coating and Extruder spheronization” Basic introduction, various methods of pellets technology, Wruster process, equipments, various process parameters and equipment parameters, Extrusion-Spheronization, Equipments, process and equipment parameters

1. PELLETIZATION TECHNOLOGY
-Kabin Maleku
(Researcher)

2. Summary
• Introduction
• Advantages and Limitations
• Pelletization Techniques
• Wruster technology
• Extrusion and spheronization
• Characterization

3. INTRODUCTION
• Pelletization:
• Pelletization can be defined as an agglomeration
(size- enlargement process that converts fine
powders or particles of bulk drugs and excipients
into small, free-flowing, more or less spherical units,
called pellets
• “Pelletization” involves the manufacture of
agglomerates with a narrow size range, usually with
mean size from 0.5 to 1.5 mm, named “pellets”
• Pellets have free-flowing properties

4. Advantages and Disadvantages
Advantages
• Uniformity of dose
• Excellent flow properties
• Prevention of dust formation
• Low surface area to volume ratio
• To deliver incompatible bioactive
agents
• Improvement of hardness and
friability
• Disperse freely throughout the GIT
• Limits localized build up of drug
• Reduce inter and intra patient
variability
• Less susceptible to dose dumping
Disadvantages
• Expensive process and /
or requires highly
specialized equipment
• Complicated with too
many process variables
as well as formulation
variables

5. PELLETIZATION TECHIQUES

6. LAYERING TECHNIQUES
• Layering processes are the most well controlled and
straight forward
• Pelletization techniques. The layering process
comprises the deposition of successive layers of
drug entities from solution, suspension or dry
powder on nuclei which may be crystals or granules
of the same material or inert starter seeds.
They are classified into two categories:
• Solution/suspension layering and
• Powder layering
• Solution/suspension layering:

7. LAYERING TECHNIQUES
• Powder layering:
• Factors affecting the process:
• powder delivery rate
• flow characteristics of powder
• Fluid bed coating: particles are fluidized and the coating
fluid sprayed on and dried. Small droplets and a low
viscosity of the spray medium ensure an even product
coating
• Different types of fluidized bed processors include top
spray coating, bottoms spray coating (Wurster coating)
and tangential spray coating (Rotor pellet coating)

8. LAYERING TECHNIQUES

9. LAYERING TECHNIQUES

10. WRUSTER PROCESS

11. VARIABLES

12. PROCESS VARIABLES
1. Fluidization Air Flow
2. Fluidization Air Humidity
3. Fluidization Air Temperature
4. Spray Rate
5. Column Height
6. Nozzle and Peristaltic pump
7. AtomiZation Air
8. Particle size

13. PRODUCT VARIABLES
1. Core particle
2. Particle surface
3. Particle size
4. Solution Viscosity and Solution/Solid
Concentration

14. EQUIPMENT VARIABLES
• BASEPLATE TYPE
• NOZZLE SIZE
• FILTERBAG TYPE
• MODEL OF THE EQUIPMENT

15. Extrusion–spheronization
• Extrusion / Spheronization is a multistage process for
obtaining pellets with uniform size from wet granulates
(extrudates).
• The method involves the following main steps:
• DRY MIXING of the ingredients, in order to achieve
homogenous powder dispersions WET MASSING, in which the
powders are wet mixed to form a sufficiently plastic mass
• EXTRUSION STAGE, in which the wet mass is shaped into
cylindrical segments with a uniform diameter
• SPHERONIZATION STAGE, in which the small cylinders are
rolled into solid spheres (spheroids)
• DRYING of the spheroids, in order to achieve the desired final
moisture content
• SCREENING (optional), to achieve the desired narrow size
distribution

16. EXTRUSION / SPHERONIZATION

17. EXTRUSION / SPHERONIZATION

18. EXTRUSION / SPHERONIZATION

19. SPHERONIZATION

20. Parameters Affecting Quality Of Pellets
In Extrusion- Spheronization Process
1. Equipment parameters
2. Process parameters

21. Equipment parameters
1. Mixer
2. Extruder
3. Friction plate
4. Extrusion screen

22. Process parameters
1. Extrusion speed
2. Extrusion temperature
3. Spheronizer load
4. Spheronization time
5. Spheronization speed
6. Drying method

23. CHARACTERIZATION OF PELLETS
1. Pellets size distribution
2. Pellets shape
3. Surface morphology (SEM)
4. Specific surface area
5. Friability
6. Disintegration Time
7. Dissolution
8. Density
9. Porosity
10.Tensile strength

24. REFRENCES
1. Isaac Ghebre-Sellassie, Multiparticulate oral drug delivery, informa
healthcare New York: Marcel Dekker (1994)
2. Mircea Hirjau, Anca Cecilia Nicoara,Victoria Hirjau, D. Lupuleasa,
Pelletization Techniques used in Pharmaceutical fields Practica Farmaceutică
– Vol. 4, Nr. 3-4, An 2011, 206-211
3. Harrison, P.J; Newton, J.M.; Rowe, R.C. The application of capillary rheometry
to the extrusion of wet powder masses Int. J. Pharm., 987, 35, 235-42
4. Devices GSI. Pharmaceutical Pelletization Technology. Vol. 37. Marcel
Dekker Inc.; 1989, pp. 30-100
5. Breitenbach J, Melt extrusion: from process to drug delivery technology,
European Journal of Pharmaceutics and Biopharmaceutics, 54, 2002,
107-117
6. Sagar Muley , Tanaji Nandgude, Sushilkumar Podda, Extrusion–
spheronization a promising pelletization technique: In-depth review, asian
journal of pharmaceutical sciences 11 (2016) 684–699
7. J.M.NewtonaS.R.ChapmanaR.C.Roweb, The influence of process variables on
the preparation and properties of spherical granules by the process of
extrusion and spheronisation, International Journal of Pharmaceutics,
Volume 120, Issue 1, 16 June 1995, Pages 101-109

25. THANK YOU
Pharmashastra