Micronization

WHAT IS MICRONIZATION?

Micronization is the process of reducing the average diameter of a solid material's particles. The term micronization is used when the particles that are produced are only a few micrometres in diameter. It is purely a physical operation by Air Jet Mill, which works on the principle of particle-to-particle collision using clean compressed air. Modern applications in the pharmaceutical industry require average particle diameters to micrometer scale.


WHY MICRONIZATION?

Within the Pharmaceutical industry it is a widely accepted fact that, finer the particle size of API used in formulation, better the dissolution which leads to faster absorption by the human body. Particle size plays a major role in designing different drug delivery systems e.g. Inhalers, Sustained Release (SR) Formulation etc.

The conventional way of particle size reduction was done with mechanical mills like Multi Mill, Pulverizer and Micro Pulverzier which could give particle size upto 40-50 microns. However these equipments have its limitations to go below certain particle size. Since there are moving parts inside the mills heat is evolved due to friction and several APIs being heat sensitive cannot be exposed to such processing methods. Therefore particle size reduction to micron level i.e. micronizing is best done using an Air Jet Mill.


ADVANTAGES OF MIRCONIZATION

The improvement in the physical properties of the APIs after Micronization leads to optimization of the drug delivery system of finished formulation. The broad spectrum of advantages are as under:

  • Uniformity of particle size
  • Better solubility
  • Improved bio-availability
  • Enhanced clinical efficacy
  • Improved appearance / brightness
  • Increased surface area


MESH-MICRON TABLE

Conversion table Mesh to Micron
 Mesh Mesh Micron Mesh Mesh Micron
 B.S.S. A.S.T.M. µ Size B.S.S. A.S.T.M. µ Size
 18 20 850 120 120 120
 22 25 710 150 140 105
 25 30 600 170 170 90
 30 35 500 200 200 75
 36 40 420 240 230 63
 44 45 355 300 270 53
 52 50 300 350 325 45
 60 60 250 400 400 37
 72 70 210 500 - 25
 85 80 180 - - 10
 100 100 150 - - 5