Tablet compression physics includes: Transmission of forces during compression. Distribution of forces in tablets. The effect of applied pressure on the. relative volume of the powder. Interparticulate adhesion and cohesion.
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Which forces are involved in compression of tablets?
Because most of particle have water, and moisture content is also pivotal to the tabletability. In die compaction, particles undergo compression and compactibility. At the compression stage, surface and friction contributions, such as those from van der Waals and electrostatic interactions, are more prevalent.
What is Heckel plot role in tablet physics?
Heckel Plots ๏ Heckel plot is density v/s applied pressure ๏ Follows first order kinetics ๏ As porosity increases compression force also increases ๏ Thus the Heckel’s plot allows for the interpretation of the mechanism of bonding.
What is Heckel plot?
The Heckel plot shows that the curve begins to adopt a tendency corresponding to the elastic deformation of the solid compact and therefore further compression does not affect the plastic deformation of the particles and also does not affect the formation of new bonds between the particles.
What is the principle of compression machine?
The basic principle behind the tablet compression machine is hydraulic pressure. This pressure is transmitted unreduced through the static fluid. Any externally applied pressure is transmitted via static fluid to all the directions in the same proportion.
How many types of compression machines are there?
Basically, the tablet compressions are divided into two types which are single rotary tablet press and double punch rotary press.
What is compaction physics?
Compaction: compaction of a powder is a general term used to describe a situation in which powdered material is subjected to some level of mechanical force. The physics of compaction may be simply stated as the compression & consolidation of two phase (particulate solid & gas) systems due to the applied force.
What is the difference between compaction and compression?
Compression is a process of compressing, or increase in density or lessening in the bulk volume of granules or powder. Compaction is the process of alteration of powders into a coherent specimen or compacting powder or granules.
Why pre compression is done in tablet manufacturing?
Cause: Pre-compression is used to remove the entrapped air in the tablet which we discussed earlier. However, too much pre-compression will lead to manufacturing of thin tablets. Too thin thickness can lead to fractures or creation of another layer of the tablet.
What is the importance of Heckel equation?
The Heckel equation is one of the most useful equations for describing the compaction properties of pharmaceutical powders. Important material properties (e.g., yield strength) of powders can be derived using Heckel analysis. Two types of Heckel analysis are in common use.
What is Kawakita equation?
The behavior of both the powder and its formulations in the tapping procedure were compared using numerical constants obtained from Kawakita plots. The Kawakita equation, which is used for assessing the flow properties of powders, is given by: N C = N a + 1 ab (2)
What is compression and consolidation?
1. Compaction is the compression of soil by the expulsion of air from the voids of the soil. Consolidation is the compression of soil by the expulsion of water from voids of the soil.
What is mottling in tablets?
โMottling’ is the term used to describe an unequal. distribution of colour on a tablet, with light or dark spots. standing out in an otherwise uniform surface. Reason: One cause of mottling may be a coloured drug, whose colour differs from the colour of excipients used for.
What is pre compression force?
Pre-compression force mainly required for removing the entrapped air during compression. The hardness of the compressed tablet prominently governed by main compression force.
What is elastic and plastic deformation?
When energy goes into changing the shape of some material and it stays changed, that is said to be plastic deformation. When the material goes back to its original form, that’s elastic deformation.
What is tooling in tablet compression?
Tooling can be defined as tools to craft a particular shape. Tabletting tools i.e., Punches and dies are essential tools to shape any granules into a solid dosage form by applying compaction force in a compression machine.
What is dwell time in tablet compression?
In tablet compression, dwell time is the time that the punch head remains in contact with the compression roller. It is defined as the amount of time that the compression force applied when forming the tablet is above 90% of its peak value.
What is direct compression tablet formulation?
From the term “direct compression”, this method can be defined as basically mixing and processing of formulation ingredients then compressing into tablets. The tablets are obtained directly from the powder API or other excipients.
Which part of tablet compression machine is stationary?
Tablet Press Ejection Cam Remember, after compression, the tablet is always fixed within the die systems (space between lower and upper punches).
Which oil is used in compression machine?
The oil type used in most Forney compression machines is Dexron III Automatic Transmission Fluid (ATF).
Why do tablet compression machines have odd numbers?
Double rotary station compression machine has odd number of stations for dynamic balancing of machine. 2.To avoid machine vibration and excess noise. If it has even number of stations then both punches arrives simultaneously on rollers. Due to this there will be very high load on motor.
What is powder compression?
Powder compression refers to the reduction in volume of a powder through the application of a force. This force via compression activity, then increases the proximity of particle surfaces, resulting to the formation of bonds between particles, thus, providing powder coherence: a compact is formed.
What does 95% compaction mean?
95 percent compaction means that the soil has been compacted to 95 percent of the possible density of the soil through compactive efforts. Maximum dry density, along with optimum moisture content, is determined in the laboratory and provides the target for field compaction.
What is the difference between D tooling and B tooling?
B Tooling: the same as BB tooling, only difference is the lower punch length is just 3 and 9/16th inch. D Tooling: its punches and dies usually have thicker diameter or greater diameter of their body as well as the tip of punches with greater outer diameter compared to B tooling.
What is compaction in tablet?
Compaction process of pharmaceutical powders consists of filling process of powders into a die, compressing process of filled powders in a die by upper and lower punches and ejection process of a compacted tablet from a die.