Effect of friction, distribution of force, compaction and solubility suraj seminar

1. EFFECT OF FRICTION , DISTRIBUTION OF FORCE, COMPACTION
AND SOLUBILITY
RAJGAD DNYANPEETH COLLEGE OF PHARMACY, BHOR,
PUNE (412206)
Presented by :
Pund Suraj Babanrao
M. Pharm 1st Year (Pharmaceutics)
R.D’s College of Pharmacy Bhor, Pune

3. Contents
 Effect of Friction
 Distribution of Force
 Compaction Profile
 Solubility

4. Effect of Friction
Two major Component to the Frictional force:
1. Interparticulate Friction:
 this arises at particle/ particle contacts and can be
expressed in term of a coefficient of interparticulate
friction m1. it is more significant at low applied loads.
 Material that reduced this effect are reffered to as
Glidants.
 Eg. Colloidal silica, talc, corn starch

5. 2. Die-wall Friction:
 This result from material being pressed against the die wall
and moved down it; it is expressed as mw, the coefficient of
die wall friction.
 Most tablets contain a small amount of an additive design
to reduced die wall friction; such additives are called
lubricants.
Ex. Mg. stearate, talc, PEG, Waxes, stearic acid

6. Distribution Of Force
Fm= Fa+Fb
2
Fa = FI + Fd
Fa= Force applied to upper punch.
FI= force transmitted to lower punch
Fd= is the reaction at the die wall due to friction at the
surface.
Fm= mean force

7. Compaction
Compaction is defined as ‘Compression & Consolidation’ of
a two phase system (particulate solid-gas) due to applied
force.

8. Compaction Profile
 Radial pressures due to the attempt of material to expand
horizontally.
 Axial pressure is due to attempt of material to constrict
vertically.
QA= shows early repacking
AB= elastic deformation
BC= plastic deformation
CD= Elastic recovery
DE= plastic recovery

9. Energy involved in Compaction
 Tablet machines, roller compactors, and similar types of
equipment required a high input of mechanical work.
 The work involve in various phase of tablets operation
includes.
 That necessary to overcome friction between particles.
 That necessary to overcome friction betweent the particles
and machine parts.
 That required to induce elastic and / plastic deformation of
the materials,
 That required to cause brittle fracture within the materials,
 That associated with the mechanical operation of various
machine parts.

10. Solubility
 Solubility is defined as Quantitative terms as
concentration of solute in concentration of solute in
concentrated solution at a certain temprature , and in
qualitative way it can be defined as a spontaneous
interaction of two or more substance to form a
homogenious molecular dispersion.

11. Importance of Solubility
 Therapeutics effectiveness of a drug depends upon the
bioavailability and ultimately upon the solubility of drug
molecule.
 It is important parameter to achieve desired concentration
of drug in systemic circulation for pharmacological
response to be shown.
 Any drug to be absorbed must be soluble or present in the
form of an aqueous solution at the site of absorption.

12. Reference
 The theory & practice of industrial pharmacy- Lachman
 Text book of biopharmaceutics and pharmacokinetics by
brahmankar, page no. 349-366
 Internet