1. Multi station rotary presses
Prof. R. Shanthini Oct 2012
Source:

3. Although tablet compressing machinery has undergone numerous mechanical modifications over the years, the compaction of materials between a pair of moving punches within a stationary die has remained unchanged
The principle modification from earlier equipment has been an increase in production rate which is regulated by
Number of tooling sets
Number of compression stations
Rotational speed of the press
Prof. R. Shanthini Oct 2012
Source: Assoc. Prof. Dr. Jomjai Peerapattana, Faculty of Pharmaceutical Sciences, Khon Kaen University

4. Special adaptations of tablet machines allow for the compression of layered tablets and coated tablets
A device that chills the compression components to allow for the compression of low-melting point substances such as waxes i.e. suppositories
Prof. R. Shanthini Oct 2012
Source: Assoc. Prof. Dr. Jomjai Peerapattana, Faculty of Pharmaceutical Sciences, Khon Kaen University

5. Compression
The ultimate test of a tablet formulation and granulation process is whether the granulation can be compressed on a high-speed tablet press.
During compression, the tablet press performs the following functions:
Filling of empty die cavity with granulation.
Precompression of granulation (optional).
Compression of granules.
Ejection of the tablet from the die cavity and take-off of compressed tablet.
Prof. R. Shanthini Oct 2012

6. When evaluating the compression characteristics of a particular formulation, prolonged trial runs at press speeds equal to that to be used in normal production should be tried.
Only then are potential problems such as sticking to the punch surface, tablet hardness, capping, and weight variation detected.
High-speed tablet compression depends on the ability of the press to interact with granulation.
Prof. R. Shanthini Oct 2012

7. Following are the parameters to be considered while choosing speed of press.
Granulation feed rate.
Delivery system should not change the particle size distribution.
System should not cause segregation of coarse and fine particles, nor it should induce static charges.
Prof. R. Shanthini Oct 2012

8. For high-speed machines, induced die feed systems is necessary.
The die feed system must be able to fill the die cavities adequately in the short period of time that the die is passing under the feed frame.
The smaller the tablet , the more difficult it is to get a uniform fill a high press speeds.
For high-speed machines, induced die feed systems is necessary.
These are available with a variety of feed paddles and with variable speed capabilities.
So that optimum feed for every granulation can be obtained.
Prof. R. Shanthini Oct 2012

9. After the die cavities are filled ,the excess is removed by the feed frame to the center of the die table.
Compression of the granulation usually occurs as a single event as the heads of the punches pass over the lower and under the upper pressure rollers.
This cause the punches to the penetrate the die to a preset depth, compacting the granulation to the thickness of the gap set between the punches.
Prof. R. Shanthini Oct 2012

10. The rapidity and dwell time in between this press event occurs is determined by the speed at which the press is rotating and by the size of compression rollers.
Larger the compressions roller, the more gradually compression force is applied and released.
Prof. R. Shanthini Oct 2012

11. The final event is ejection of compressed tablets from die cavity.
Slowing down the press speed or using larger compression rollers can often reduce capping in a formulation.
The final event is ejection of compressed tablets from die cavity.
During compression, the granulation is compacted to form tablet, bonds within compressible material must be formed which results in sticking.
Prof. R. Shanthini Oct 2012

12. High level of lubricant or over blending can result in a soft tablet, decrease in wettability of the powder and an extension of the dissolution time.
Binding to die walls can also be overcome by designing the die to be to inch wider at the upper portion than at the center in order to relieve pressure during ejection.
Prof. R. Shanthini Oct 2012

13. DIFFERENT PUNCHES & DIES
Prof. R. Shanthini Oct 2012

14. Tableting methods (already seen)
Dry methods
Direct compression
Dry granulation
Wet methods
Wet granulation
Prof. R. Shanthini Oct 2012
Source: Assoc. Prof. Dr. Jomjai Peerapattana, Faculty of Pharmaceutical Sciences, Khon Kaen University

15. 1. Milling and mixing of drugs and excipients
WET GRANULATION
DRY GRANULATION
DIRECT COMPRESSION
1. Milling and mixing of drugs and excipients
2. Preparation of binder solution
2. Compression into slugs or roll compaction
2. Compression of tablet
3. Wet massing by addition of binder solution or granulating solvent
3. Milling and screening of slugs and compacted powder
4. Screening of wet mass
4. Mixing with lubricant and disintegrant
5. Drying of the wet granules
5. Compression of tablet
6. Screening of dry granules
7. Blending with lubricant and disintegrant to produce “running powder”
8. Compression of tablet
Prof. R. Shanthini Oct 2012

16. Direct compression
Tablets are compressed directly from powder blends of the active ingredient and suitable excipients
No pretreatment of the powder blends by wet or dry granulation procedures is necessary
Prof. R. Shanthini Oct 2012
Source: Assoc. Prof. Dr. Jomjai Peerapattana, Faculty of Pharmaceutical Sciences, Khon Kaen University

17. Advantages
Economy
Machine: fewer manufacturing steps and pieces of equipment
Labor: reduce labor costs
Less process validation
Lower consumption of power
Prof. R. Shanthini Oct 2012
Source: Assoc. Prof. Dr. Jomjai Peerapattana, Faculty of Pharmaceutical Sciences, Khon Kaen University

18. Advantages (contd.) Elimination of granulation process
Heat (wet granulation)
Moisture (wet granulation)
High pressure (dry granulation)
Processing without the need for moisture and heat which is inherent in most wet granulation procedures
Avoidance of high compaction pressures involves in producing tablets by slugging or roll compaction
Prof. R. Shanthini Oct 2012
Source: Assoc. Prof. Dr. Jomjai Peerapattana, Faculty of Pharmaceutical Sciences, Khon Kaen University

19. Advantages (contd.)
Elimination of variabilities in wet granulation processing
Viscosity of the granulating solution (depend on its temperature),
How long it has been prepared,
Rate of binder addition and kneading can affect the properties of the granules formed
The granulating solution, the type and length of mixing and the method and rate of wet and dry screening can change the density and particle size of the granules, which can have a major effect on fill weight and compaction qualities
Prof. R. Shanthini Oct 2012
Source: Assoc. Prof. Dr. Jomjai Peerapattana, Faculty of Pharmaceutical Sciences, Khon Kaen University

20. Advantages (contd.) Type and rate of drying
can lead to unblending as soluble active ingredients migrate to the surfaces of the drying granules
Less unit processes incorporated in production means less chances of batch-to-batch variation are compounded
Prof. R. Shanthini Oct 2012
Source: Assoc. Prof. Dr. Jomjai Peerapattana, Faculty of Pharmaceutical Sciences, Khon Kaen University

21. Direct compression fillers
Common materials that have been modified in the chemical manufacturing process to improve fluidity and compressibility
Prof. R. Shanthini Oct 2012
Source: Assoc. Prof. Dr. Jomjai Peerapattana, Faculty of Pharmaceutical Sciences, Khon Kaen University

22. Soluble fillers
Spray dried lactose (good flowability; less compressibility)
Fast-Flo lactose (much more compressible and highly fluid)
Tabletose: aggromerate form of lactose (More compressible than spray dried but less compressible than Fast Flo lactose)
Di-Pac: cocrystallization of 97% sucrose and 3% modified dextrin
Sorbitol
Maltodextrin (Highly compressible; completely soluble )
And more….
Prof. R. Shanthini Oct 2012
Source: Assoc. Prof. Dr. Jomjai Peerapattana, Faculty of Pharmaceutical Sciences, Khon Kaen University

23. Insoluble fillers
Starch 1500: intact starch grains and ruptured starch grains that have been partially hydrolyzed and subsequently agglomerated
Era-Tab: spray-dried rice starch (good fluidity; compressibility depends on moisture)
Avicel: microcrystalline cellulose (the most important tablet excipient developed in modern times; most compressible)
Dicalcium phosphate (Emcompress or DiTab)
Prof. R. Shanthini Oct 2012
Source: Assoc. Prof. Dr. Jomjai Peerapattana, Faculty of Pharmaceutical Sciences, Khon Kaen University