Prof. R. Shanthini 22 Oct 2012 Source: Multi station rotary presses.

Prof. R. Shanthini 22 Oct 2012

Source: http://vivekkivani.blogspot.com/

Multi station rotary presses


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

Although tablet compressing machinery has Although tablet compressing machinery has undergone numerous mechanical modifications undergone numerous mechanical modifications over the years, over the years, the compaction of materials the compaction of materials between a pair of moving punches within a between a pair of moving punches within a stationary die has remained unchangedstationary die has remained unchanged

The principle modification from earlier equipment The principle modification from earlier equipment has been an increase in production rate which is has been an increase in production rate which is regulated by regulated by Number of tooling setsNumber of tooling sets Number of compression stationsNumber of compression stations

Rotational speed of the pressRotational speed of the press



Special adaptations of tablet machines allow for Special adaptations of tablet machines allow for the compression of layered tablets and coated the compression of layered tablets and coated tabletstablets

A device that chills the compression A device that chills the compression components to allow for the compression of components to allow for the compression of low-melting point substances such as waxes i.e. low-melting point substances such as waxes i.e. suppositoriessuppositories


Compression Compression

The ultimate test of a tablet formulation and The ultimate test of a tablet formulation and granulation process is whether the granulation can granulation process is whether the granulation can be compressed on a high-speed tablet press.be compressed on a high-speed tablet press.

During compression, the tablet press performs the During compression, the tablet press performs the following functions:following functions:

1.1. Filling of empty die cavity with granulation.Filling of empty die cavity with granulation.

2.2. Precompression of granulation (optional).Precompression of granulation (optional).

3.3. Compression of granules.Compression of granules.

4.4. Ejection of the tablet from the die cavity and take-off of Ejection of the tablet from the die cavity and take-off of compressed tablet.compressed tablet.


When evaluating the compression characteristics When evaluating the compression characteristics of a particular formulation, prolonged trial runs at of a particular formulation, prolonged trial runs at press speeds equal to that to be used in normal press speeds equal to that to be used in normal production should be tried.production should be tried.

Only then are potential problems such as sticking Only then are potential problems such as sticking to the punch surface, tablet hardness, capping, to the punch surface, tablet hardness, capping, and weight variation detected.and weight variation detected.

High-speed tablet compression depends on the High-speed tablet compression depends on the ability of the press to interact with granulation.ability of the press to interact with granulation.


Following are the parameters to be considered Following are the parameters to be considered while choosing speed of press.while choosing speed of press.1.1. Granulation feed rate.Granulation feed rate.

2.2. Delivery system should not change the particle size Delivery system should not change the particle size distribution.distribution.

3.3. System should not cause segregation of coarse and fine System should not cause segregation of coarse and fine particles, nor it should induce static charges.particles, nor it should induce static charges.


The die feed system must be able to fill the die The die feed system must be able to fill the die cavities adequately in the short period of time cavities adequately in the short period of time that the die is passing under the feed frame. that the die is passing under the feed frame.

The smaller the tablet , the more difficult it is to The smaller the tablet , the more difficult it is to get a uniform fill a high press speeds.get a uniform fill a high press speeds.

For high-speed machines, induced die feed For high-speed machines, induced die feed systems is necessary.systems is necessary.

These are available with a variety of feed These are available with a variety of feed paddles and with variable speed capabilities.paddles and with variable speed capabilities.

So that optimum feed for every granulation can So that optimum feed for every granulation can be obtained.be obtained.


After the die cavities are filled ,the excess is After the die cavities are filled ,the excess is removed by the feed frame to the center of the die removed by the feed frame to the center of the die table.table.

Compression of the granulation usually occurs as Compression of the granulation usually occurs as a single event as the heads of the punches pass a single event as the heads of the punches pass over the lower and under the upper pressure over the lower and under the upper pressure rollers.rollers.

This cause the punches to the penetrate the die to This cause the punches to the penetrate the die to a preset depth, compacting the granulation to the a preset depth, compacting the granulation to the thickness of the gap set between the punches.thickness of the gap set between the punches.


The rapidity and dwell time in between this press The rapidity and dwell time in between this press event occurs is determined by the speed at which event occurs is determined by the speed at which the press is rotating and by the size of the press is rotating and by the size of compression rollers.compression rollers.

Larger the compressions roller, the more gradually Larger the compressions roller, the more gradually compression force is applied and released.compression force is applied and released.


Slowing down the press speed or using larger Slowing down the press speed or using larger compression rollers can often reduce capping in compression rollers can often reduce capping in a formulation.a formulation.

The final event is ejection of compressed tablets The final event is ejection of compressed tablets from die cavity.from die cavity.

During compression, the granulation is During compression, the granulation is compacted to form tablet, bonds within compacted to form tablet, bonds within compressible material must be formed which compressible material must be formed which results in sticking.results in sticking.


High level of lubricant or over blending can result High level of lubricant or over blending can result in a soft tablet, decrease in wettability of the in a soft tablet, decrease in wettability of the powder and an extension of the dissolution time.powder and an extension of the dissolution time.

Binding to die walls can also be overcome by Binding to die walls can also be overcome by designing the die to be 0.001 to 0.005 inch wider designing the die to be 0.001 to 0.005 inch wider at the upper portion than at the center in order to at the upper portion than at the center in order to relieve pressure during ejection.relieve pressure during ejection.


DIFFERENT PUNCHES & DIES



Tableting methods (already seen)

Dry methodsDry methods Direct compressionDirect compression Dry granulationDry granulation

Wet methodsWet methods Wet granulationWet granulation


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



Direct compression

Tablets are compressed directly from Tablets are compressed directly from powder blends of the active ingredient and powder blends of the active ingredient and suitable excipientssuitable excipients

No pretreatment of the powder blends by No pretreatment of the powder blends by wet or dry granulation procedures is wet or dry granulation procedures is necessarynecessary



AdvantagesEconomyEconomy

Machine: fewer manufacturing steps and pieces of Machine: fewer manufacturing steps and pieces of equipmentequipment

Labor: reduce labor costsLabor: reduce labor costs Less process validationLess process validation Lower consumption of powerLower consumption of power



Advantages (contd.)

Elimination of granulation processElimination of granulation process Heat (wet granulation)Heat (wet granulation) Moisture (wet granulation)Moisture (wet granulation) High pressure (dry granulation) High pressure (dry granulation) Processing without the need for moisture and heat Processing without the need for moisture and heat

which is inherent in most wet granulation which is inherent in most wet granulation procedures procedures

Avoidance of high compaction pressures involves Avoidance of high compaction pressures involves in producing tablets by slugging or roll compactionin producing tablets by slugging or roll compaction



Advantages (contd.)

Elimination of variabilities in wet granulation Elimination of variabilities in wet granulation processingprocessing

Viscosity of the granulating solution (depend on its Viscosity of the granulating solution (depend on its temperature), temperature),

How long it has been prepared,How long it has been prepared, Rate of binder addition and kneading can affect the Rate of binder addition and kneading can affect the

properties of the granules formedproperties of the granules formed The granulating solution, the type and length of mixing The granulating solution, the type and length of mixing

and the method and rate of wet and dry screening can and the method and rate of wet and dry screening can change the density and particle size of the granules, change the density and particle size of the granules, which can have a major effect on fill weight and which can have a major effect on fill weight and compaction qualitiescompaction qualities



Advantages (contd.)

Type and rate of drying Type and rate of drying can lead to unblending as soluble active ingredients can lead to unblending as soluble active ingredients

migrate to the surfaces of the drying granulesmigrate to the surfaces of the drying granules

Less unit processes incorporated in Less unit processes incorporated in production means less chances of batch-to-production means less chances of batch-to-batch variation are compoundedbatch variation are compounded



Direct compression fillers

Common materials that have been Common materials that have been modified in the chemical manufacturing modified in the chemical manufacturing process to improve fluidity and process to improve fluidity and compressibilitycompressibility



Soluble fillers Spray dried lactose (good flowability; less compressibility)Spray dried lactose (good flowability; less compressibility) Fast-Flo lactose (much more compressible and highly fluid) Fast-Flo lactose (much more compressible and highly fluid) Tabletose: aggromerate form of lactose (More compressible Tabletose: aggromerate form of lactose (More compressible

than spray dried but less compressible than Fast Flo lactose)than spray dried but less compressible than Fast Flo lactose) Di-Pac: cocrystallization of 97% sucrose and 3% modified Di-Pac: cocrystallization of 97% sucrose and 3% modified

dextrindextrin SorbitolSorbitol Maltodextrin (Highly compressible; completely soluble )Maltodextrin (Highly compressible; completely soluble ) And more….And more….



Insoluble fillers Starch 1500: intact starch grains and ruptured starch Starch 1500: intact starch grains and ruptured starch

grains that have been partially hydrolyzed and grains that have been partially hydrolyzed and subsequently agglomeratedsubsequently agglomerated

Era-Tab: spray-dried rice starch (good fluidity; Era-Tab: spray-dried rice starch (good fluidity; compressibility depends on moisture)compressibility depends on moisture)

Avicel: microcrystalline cellulose (the most important Avicel: microcrystalline cellulose (the most important tablet excipient developed in modern times; most tablet excipient developed in modern times; most compressible)compressible)

Dicalcium phosphate (Emcompress or DiTab)Dicalcium phosphate (Emcompress or DiTab)

Prof. R. Shanthini 22 Oct 2012 Source: Multi station rotary presses.

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Transcript of Prof. R. Shanthini 22 Oct 2012 Source: Multi station rotary presses.