Tablets

1
Multi station rotary presses
Source http//vivekkivani.blogspot.com/
2
(No Transcript)
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

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

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.

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.

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.

8

• 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.

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.

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.

11

• 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.

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 0.001 to 0.005 inch wider
  at the upper portion than at the center in order
  to relieve pressure during ejection.

13
DIFFERENT PUNCHES DIES
14
Tableting methods (already seen)

• Dry methods
• Direct compression
• Dry granulation
• Wet methods
• Wet granulation

Source Assoc. Prof. Dr. Jomjai Peerapattana,
Faculty of Pharmaceutical Sciences, Khon Kaen
University
15
WET GRANULATION DRY GRANULATION DIRECT COMPRESSION
1. Milling and mixing of drugs and excipients 1. Milling and mixing of drugs and excipients 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    
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

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

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

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

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

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

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.

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)

Source Assoc. Prof. Dr. Jomjai Peerapattana,
Faculty of Pharmaceutical Sciences, Khon Kaen
University