Microcrystalline cellulose in pharmaceutical products

Microcrystalline cellulose is the most widely used excipient in pharmaceutical industries to manufacture tablets.

Microcrystalline cellulose is also known as MCC or Avicel.

Role of Microcrystalline cellulose

Microcrystalline cellulose is a unique excipient that has many properties such as

• Diluent
• Disintegrant
• Dry binder
• Glident 
• Lubricant

Microcrystalline cellulose as Diluent

• Microcrystalline cellulose is used as a diluent in wet granulation, dry granulation and direct compression.

Microcrystalline cellulose as Disintegrant

• Microcrystalline cellulose is also used as a disintegrant in the granulation of tablets and capsules.

Microcrystalline cellulose as Binder

• MCC is also known as a dry binder because it gives strength to the tablet.

Microcrystalline cellulose as Glident and lubricant

• MCC improve flow and is also used as a glidant and lubricant

Concentration of Microcrystalline cellulose

 Avicel or MCC is used in different concentrations as

•  Diluent and binder for tablet and capsule= 20% to 90%
•  Disintegrant= 5% to 15%
• Anti-Adherent=5% to 20%

Grades of Microcrystalline cellulose

• Microcrystalline cellulose is available in different grades.
• Grades are based on moisture content and particle size.
• Following are common grades,
• Avicel PH 101
• Avicel PH 102
• Avicel PH 103
• Avicel PH 105
• Avicel PH 112
• Avicel PH 113
• Avicel PH 200
• Avicel PH 301
• Avicel PH 302

PH stands for pharmaceutical grade.

MCC is used in following manufacturing processes,

• Wet granulation
• Dry granulation
• Direct compression

MCC in wet granulation

• MCC or microcrystalline cellulose is used in wet granulation as a diluent.
• It is also used as a dry binder in wet granulation.
• It is also used as a disintegrant.
• When MC is used in wet granulation, two grades are usually used.
• One is Avicel PH 101 and the second is Avicel PH 102.
• When we have to use Avicel intra- granular we should use Avicel 101 because it is fine and its cost is also low as compared to Avicel 102.
• When we have to use Avicel extra granular in final blending then Avicel 102 is used
• 102 in the extra granular stage improves the flow properties.
• If we add Avicel 101 in, extra granular stage flow properties are affected.
• Avicel in wet granulation retains some moisture after drying and helps to prevent capping.
  

Microcrystalline cellulose in Dry granulation

• MCC in dry granulation is used as diluent.
• It is also used as a disintegrant.
• It improves compaction properties.
• MCC in dry granulation is also used as a dry binder.

Microcrystalline cellulose in Direct Compression 

• Microcrystalline cellulose is used in simple mixing or direct compression as a diluent.
• Coarse grades of MCC in direct compression improve flow properties.
• Microcrystalline cellulose in direct compression is used as a dry binder.
• It is also used as a disintegrant.
• It is used to give strength to tablet edges.

Avicel PH 101

• Avicel 101 is a fine grade of MCC.
• It is usually used in wet granulation.
• It is used in the intra-granular stage.
• Its use in final blending is not recommended because its flow is poor.
• Due to poor flow weight variation may occur.
• Its particle size is 50 microns.
• It has ≤ 5% moisture contents.

Avicel PH 102

• It is coarse grade than Avicel PH 101 so it improves flow properties.
• It is used in wet granulation as a diluent and disintegrates.
• It is also used in dry granulation.
• In direct compression, acts as a dry binder and improves flow properties.
• Its particle size is 100 microns.
• It has ≤ 5% moisture content.

Avicel PH 103

• It has low moisture content.
• Its moisture level is 3%
• It is used for moisture-sensitive products.
• Its particle size is 50 microns.

Avicel PH 105

• Its particle size is 20 microns
• Its particle size is smaller than all other grades of Avicel.
• Despite having the smallest particle size it gives maximum compaction.
• It is used in dry granulation, wet granulation and direct compression
• It is also used in combination with Avicel 101 and Avicel 102.
• Moisture content is ≤5%

Avicel PH 112

• Its particle size is 100 microns.
• It has a low moisture content
• Its moisture content is 1.5%.
• It is used for moisture-sensitive products.

Avicel PH 113

• Its particle size is 50 microns.
• Its moisture content is 1.5%.
• Because of the low moisture level, it is used for moisture-sensitive products.

Avicel PH 200

• It is a coarse grade of Microcrystalline cellulose.
• Its particle size is 180 microns.
• It has the largest particle size of all Avicel grades.
• It has high flow properties.
• It is used in dry granulation.
• It is also used in wet granulation.
• Its moisture content is ≤ 5%.

Avicel PH 301

• Its particle size is 50 microns.
• Its density is high.
• It has a good flow.
• It is used for small tablets.
• Moisture content is ≤ 5%.

Avicel PH 302 

• Its particle size is 100 microns.
• Its moisture content is ≤ 5 %.

Advantages of Avicel

Avicel has many advantages some of which are given as follows,

• Coarse grades improve flow properties.
• Reduce weight variation.
• Prevent colour migration.
• Retain moisture after drying and prevent tablet capping.
• Tablet hardness is increased without affecting disintegration and dissolution profile.
• If tablet edges are weak, Avicel gives strength to the edges.