Post on 14-Nov-2014
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TABLET HARDNESS
TESTER
Instrumental Seminar
Dr. Vikas Saroch17/04/2009 Dept. Of Rasashastra
Dept. Of Rasashastra 2
CONTENTS
INTRODUCTION
TABLET HARDNESS
HISTORY
MODERN INSTRUMENTATION
WHY TEST
MEASURING UNIT
TEST METHODS
INSTRUMENTS
CONCLUSION
REFERENCES17/04/2009
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INTRODUCTION
The compressed tablet is one of the most popular dosage forms .
About one-half of all prescriptions dispensed are for tablets.
Usually one considers a compressed tablet as an oral medication.
Tablets have many other uses. The sublingual tablet, the pellet, the
wafer, and the vaginal insert are manufactured by the same procedure as an oral tablet.
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TABLET HARDNESS
Defined as “ The force required to break a tablet in a diametric compression test.”
Hard enough to withstand mechanical stress during packaging, shipment, and handling by the consumer.
Section <1216> of the USP 24/NF19 outlines a standard tablet friability test applicable to manufactured tablets.
Most compounding pharmacy would not have the apparatus specified in Section <1216>. However, there are several hand operated tablet hardness testers that might be useful.
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TABLET HARDNESS
There are various devices to test the hardness of the tablet :
Monsanto tester Strong- cobb tester Pfizer tester Erweka tester. Schleuniger tester
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HISTORY
The first tablet hardness tester was introduced around the mid-1930s.
Purely mechanical device and is still manufactured today.
Force was applied with a screw thread and spring until the tablet fractured and the hardness was read from a sliding scale graduated in ½ kg increments.
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Contd…
This was followed by the so-called Strong-Cobb tester, introduced around 1950.
The testing force was generated by a manually operated air pump and the tablet breaking force was measured on a dial graduated in 30 arbitrary units which were designated as Strong-Cobbs.
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Contd…..
The results given by the Strong-Cobb tester were not consistent with those of the earlier tester.
Electro-mechanical tablet hardness testing machines were later introduced and have evolved into electronic test instruments such as those produced by Engineering Systems.
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Modern instrumentation
Contain a motor drive system to
generate the force.
Automatically detect the tablet.
Fracture displaying the force in a
variety of units.
Measurements can be printed and /
or downloaded to a computer .17/04/2009 Dept. Of Rasashastra
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need for test
Too ‘soft’ tablets can disintegrate in transport.
Too ‘hard’ tablets could damage teeth.
Tablet strength testing is necessary for both,
research & development of new formulations, and
for quality control.
The test instruments should provide accurate
results and output these results in standard units.
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MEASURING UNIT
Newton (N) – The Newton is the SI
unit of force and is the unit that
should be used for tablet hardness
testing. 9.807 Newton = 1 kilogram
Kilopond (Kp)
Strong Cobb (Sc)
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Contd…
Strong-Cobb (SC) – The Strong-Cobb is
a legacy of the first tablet hardness
testing machines.
An arbitrary unit
Never recognized by the SI system.
1.4 Strong-Cobs are thought to equal
about 1 kg17/04/2009 Dept. Of Rasashastra
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TEST METHODS
The standard method used for tablet hardness testing is compression testing.
The tablet is placed between two jaws that crush the tablet. The machine measures the force applied to the tablet and detects when it fractures.
This method is used for research & development and for quality control.
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Monsanto Hardness Tester
Developed approximately 50 years ago.
Consists of a barrel containing a compressible spring held between two plungers.
The lower plunger is placed in contact with the tablet ,and a zero reading is taken.
The upper plunger is then forced
against a spring by turning a threaded bolt until the tablet fractures.
As a spring is compressed, a pointer rides along a gauge in the barrel to indicate the force. The force of fracture is recorded, and zero reading is deducting from it.
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Monsanto Hardness Tester
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Strong-cobb tester
Consist of a plunger activated by pumping a lever arm, which forces an anvil against a stationary platform by hydraulic pressure.
The force required to fracture the tablet is read from a hydraulic gauge.
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Pfizer tester
Operates on the same mechanical principle.
1st pliers handles are squeezed.
Tablet is compressed between a holding anvil and a piston connected to a direct force reading gauge.
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TABLET HARDNESS TESTER
Can be fitted
on either bench
or tablet ling
machine.
Includes :
Engineered
Dial Gauge,
Aluminium
Body .
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3 in 1 - Type PTB 311E
Test : Thickness,
Diameter or Length and Hardness of the same Tablet
Hardness: 2.0 - approx. 330 N (Newton)
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Tablet Hardness Test Type : PTB 302
Test the Hardness
of tablets, cores,
capsule shaped
samples.
Hardness:
2.0 - approx. 330
N
(Newton) - 550N
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CONCLUSION
All the different varieties of testing machines would give the same results (if used on the same batch of tablets).
Machine ‘accuracy’ would equal Machine ‘resolution’.
All pharmaceutical companies would use the same SI unit of measurement (N or kg) and the same constant (6 mm/min) test speed.
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References
www.pharma-test.com www.indiamart.comwww.pharmaceuticalonlin
e.com
www.google.com
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THANK YOU
17/04/2009