Microcrystalline cellulose or MCC is a pure-type crystalline cellulosic polysaccharide molecule bound by β-1,4-glucosidic bonds synthesized from the α-cellulose precursor. MCC is obtained from fibrous plant material, acid hydrolysis of cellulose using 2M hydrochloric acid at 105 °C for 15-20 minutes to reduce the degree of polymerization. It is a white crystalline and free-flowing powdery material. MCC is chemically inert and does not degrade during digestion.
This compound has good compressibility properties and is used in solid dose forms. This biocompatible material is used in food products and can be used as an anti-caking agent, stabilizer, texture modifier, or suspending agent. This compound was first invented in 1955 by Battista and Smith.
Structure of Microcrystalline Cellulose
The chemical formula of MCC is (C6H10O5)n which is also called refined wood pulp. MCC is formed by glucose subunits connected by a 1-4 beta glycosidic bond. These chains are attached together as microfibril spiraled together in plant cell walls. Each microfibril shows a high degree of three-dimensional internal bonding to produce a crystalline structure that is insoluble in water and resistant to various chemical compounds.
The weak microfibril segments among these are attached together with weaker internal bonding and create amorphous regions due to having the single-phase structure of microfibrils. The crystalline region is isolated for getting MCC.
Synthesis of Microcrystalline Cellulose
This compound is a partially depolymerized cellulosic molecule synthesized from α-cellulose precursor. It can be synthesized by a reactive extrusion process, enzyme-mediated process, mechanical grinding process, ultrasonication process, steam explosion process, and acid hydrolysis process.
In the acid hydrolysis process, mineral acids such as H2SO4, HCl, and HBr are used to destroy the amorphous regions leaving the crystalline domains.
The size of the MCC particles lower than 5 μm must not be more than 10% and the DP (degree of polymerization) is typically less than 400.
The properties of MCC can be justified by the Thermogravimetric analysis technique (TGA), differential scanning calorimetry (DSC), and differential thermal analysis (DTA) technique.
Solubility of Microcrystalline cellulose
It is insoluble in water but swells. It forms a gel-like state and is soluble in dilute Sodium hydroxide solution. MCC is insoluble in dilute acids, in acetone, in ethanol, and in toluene. MCC can be dissolved in with 8–10% of aqueous NaOH at -5 to -6°C.
Properties of Microcrystalline Cellulose
MCC is an odorless and tasteless powder prepared from pure cellulose.
MCC can be processed to different micrometer sizes for having its microcrystalline structure.
This compound has good porosity and moisture retention powers.
This biopolymer has good binding properties and cohesiveness.
It has the ability to create a dense and smooth surface that’s extremely nonfriable.
MCC can be deformed under compression but forms powerful hydrogen bonds.
MCC has higher temperature stability.
Acidic hydrolysis is used to remove the cellulose amorphous region until the microcrystalline form remains.
The melting point of microcrystalline cellulose ranges from 247-250°C and the flash point is 164 °C.
Applications of Microcrystalline Cellulose
MCC is used as a thickener, stabilizer, or emulsifier.
It is used in cosmetics as an abrasive, absorbent, anti-caking agent, and aqueous viscosity-increasing agent.
It acts as a binder, bulking agent, emulsion stabilizer, slip modifier, and texturizer
MCC can be found in various hair and skin care products as well as makeup.
It has been used as an important base material in functional foods.
It is also used to produce water-based coatings.
It is used with filler material and has a very good emulsifying capacity for oily substances.
This biopolymer is used to make bio-composites ideal for 3D printing when combined with reinforced PLA (polylactic acid).
References
Nada, A. M. A., El-Kady, M. Y., El-Sayed, E. S. A., & Amine, F. M. (2009). Preparation and characterization of microcrystalline cellulose (MCC). BioResources, 4(4), 1359-1371.
Trache, D., Hussin, M. H., Chuin, C. T. H., Sabar, S., Fazita, M. N., Taiwo, O. F., … & Haafiz, M. M. (2016). Microcrystalline cellulose: Isolation, characterization and bio-composites application—A review. International Journal of Biological Macromolecules, 93, 789-804.
Frequently Asked Questions (FAQs) about MCC
What is microcrystalline cellulose?
It is formed by glucose subunits connected by a beta 1-4 glycosidic linkage. These chains are attached together as microfibril spiraled together in plant cell walls.
What are the solvents of microcrystalline cellulose?
MCC is soluble in dilute Sodium hydroxide solution. MCC can be dissolved in with 8–10% of aqueous NaOH at -5 to -6°C.
What is the melting point of microcrystalline cellulose (MCC) powder?
The melting point of MCC ranges from 247-250°C and the flash point is 164 °C.
Is microcrystalline cellulose (MCC) soluble in water?
MCC is completely insoluble in water but swells.
What is microcrystalline cellulose used for in the pharmaceutical industry?
It is used as a good thickener, stabilizer, or emulsifier material. It is used in cosmetics as an abrasive, anti-caking agent, absorbent, aqueous viscosity-increasing material.
