Effect of Compression Force on Tablet properties and Strength of Tablet.
- 1. Welcome
- 2. Presentation On Effect of Compression Force on Tablet properties and Strength of Tablet. Group-A Rummatul Jannat Annesha 20150109006 Rajib Hossain 20151109021 Mostafa Al Amin 20151109025 Madhuri Mondal 20150109031 Afroza Akter Luna 201r0109026 Mizanur Rahaman 20151209020 Mir. Imran Alim 20151109023 Tumpa Kar 20150109028 Mohidul Islam 20151209035 Bannya Mollick 20140109041 MEMBERS 1
- 3. Tablet: Unit dosage form of medicament. Prepared by compression. Tablet Compression: Compression force: Force influenced the compaction of granules. Given by die and punch. After the preparation of granules they are compressed to get final product called compression. Fig: Tablet compression. 2
- 4. Principle of Tablet Compression: In the tablet compression main principle is compressing of the upper and lower punch in a die hole, the hydraulic pressure plays a key role. Fig: Tablet compression. 3
- 5. Different Stages of Tablet Compression Process: 4
- 6. Properties of tablet influenced by compression: 01. Density and porosity: Compressional Force Density Compressional Force Porosity 5
- 7. 02. Hardness and tensile strength: Compressional force Hardness Compressional force Tensile strength 6
- 8. 03. Specific surface area: 04. Disintegration: Compressional force Specific surface area Compressional force Disintegration time NB: Both decrease by the further increase of compressional force. 7
- 9. Dissolution: The effect of applied pressure dissolution rate may be considered from view point of disintegrating and non-disintegrating tablets. 8
- 10. Tablet compression machine: • Hopper • Dies • Cam tracks • Feed frame • Die lock screw • Punches • Die table • Die socket Tablet compression basic components: 9
- 11. Common tableting problem and there remedy during tablet compression: 10
- 12. Capping and Lamination remedy: Picking and Sticking remedy: Slowing tableting rate Reducing the pressure adjustments Hygroscopic substance Replacing the worn out dies and punches Granules and required amount of the powders Designed as large as possible By using chromium plated punches Adding a lubricant Higher melting point materials as diluents Added colloidal silica 11
- 13. Strength of tablet Tablet require certain amount of strength to withstand mechanical shocks of handling during manufacturing ,packaging and shipping. In order to show desired response each tablet should posses optimum strength. When a tablet is subjected to such a force the response can be interpreted on the basis of the bond summation or fracture mechanics concepts. 12
- 14. Measurement of strength 1. Diametral Compression test. 2.Axial tensile strength. 1.Diametral Compression test: The most common strength in pharmaceutical application. Used to calculate the redial tensile strength of a tablet. During redial tensile strength measurement, the fracture occurs through a diametral cross section of the tablet. Reflects the average strength of tablet rather than the strength of the weakest plane in the tablet. 13
- 15. Measurement of strength 1. Diametral Compression test. 2.Axial tensile strength. 1.Diametral Compression test: The most common strength in pharmaceutical application. Used to calculate the redial tensile strength of a tablet. During redial tensile strength measurement, the fracture occurs through a diametral cross section of the tablet. Reflects the average strength of tablet rather than the strength of the weakest plane in the tablet. 1 4
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- 17. 2.Axial tensile strength: The force necessary to break the tablet is obtained by pulling the tablet parallel to the applied force during the formation of the tablet and this force is then use to calculate the axial tensile strength. During axial tensile strength measurement, the fracture will occurs through the weakest plane in the tablet. 17
- 18. 1. Bond summation concept: The bonds will be holding the particles together and the breakage of this bonds during strength testing are emphasized. 2. Fracture mechanics concepts: Focus is on the propagation of cracks in the tablet during strength testing. Theoretical models of mechanical strength 1. Bond summation concept. 2. Fracture mechanics concepts. 17
- 19. Factors affecting strength of the tablet: Particle size. Moisture content Particle shape and surface roughness Compaction pressure Binders Lubricants Entrapped air Porosity 18
- 20. Particle size Decrease in particle size increase the stability of the tablets. Good flow property to have uniformity of weight of the tablet. The flow property of powder depends on …… o Particle shape o Porosity o Density o Moisture of the powder The rate of flow ∝ size of particles of powder 19
- 21. Moisture content A small proportion of moisture content is desirable for the formation of a coherent tablet. Some amount of moisture present on the powder surface is just sufficient to fill the reaming voids in the bed. Further increase in compression force results in this water being squeeze out to the surface of tablet. The expelled moisture may act as lubricant at die wall ,but it causes material to stick to punch faces. At low moisture content there will be increase in die wall friction due to increase stress , hence the tablet hardness will be poor. At high moisture level the die wall friction is reduced owing to lubricating effect of moisture. Optimum moisture content is in the range of 0.5-4%. 20
- 22. Compaction pressure The compaction pressure and speed affect the strength of the resulting tablet. A material which undergoes time-dependent plastic or elastic deformation is referred to as a viscous or viscoelastic material. For such a material , a change in the compression speed significantly affect the deformation of the material. The effect of compression speed has been evaluated by calculating the strain rate sensitivity. A fragmenting material ,has been shown to be less affected by variation in compression speed. 21
- 23. Binder A binder is a material that is added to a formulation in order to improve mechanical strength of a tablet. In direct compression, it is generally considered that a binder should have a high compactibility to ensure the mechanical strength of the tablet mixture. The addition of a binder to a compound change the surface property of the course compound particle as they are covered by the small binder particles. Addition of binder which increase elasticity can decrease tablet strength because of the breakage of bonds as the compaction pressure is released. Commonly used binders are…… Starch Gelatin Acacia Sodium alginate Methyl cellulose 22
- 24. Lubricants Lubricants increase the strength of the tablet The lubricant film interfere with the bonding property of host particle by acting as a physical barrier. When the tablet is blended lightly ,the lubricant is present as a free fraction. Lubricant use to improve granule flow , minimize die wall friction and prevent adhesion of the granules to the punch faces. 23
- 25. Entrapped air When the air does not freely escape from the granules in the die cavity , the force created by the expansion of the entrapped air may be sufficient to disrupt the bond. The presence of entrapped air produce a tablet which can be broken easily & it lowers the tablet strength. 24
- 26. Porosity When particles of large size is subjected to light compression the tablet will be highly porous –low tablet strength. Reduction in porosity is due to granule fragmentation giving smaller particles which may be more closely packed and plastic deformation which allows the granules to flow into the void spaces. 25
- 27. Conclusion: There are a lot of out come of compression force and strength on tablet properties. The relative value of tensile strength, compression and shear stresses within the tablet varies depending on the characteristics of tablet. 26
- 28. Thank You.