Shin-Etsu Chemical Co., Ltd. began to produce water soluble cellulose ethers in 1962, with the trade name METOLOSE®.
METOLOSE® can be used as a binder for solid dosage forms such as tablets and granules. It also provides a variety of functions such as water retention, thickening, protective colloid, surface activity, sustained release, etc. It is also regarded as a non-digestive fiber. METOLOSE® consists of Methylcellulose (Methylcellulose USP) and three substitution types of Hydroxypropylmethylcellulose (Hypromellose USP) each available in several grades differing in viscosity.
Characteristics of METOLOSE®
Odorless and tasteless
METOLOSE® is a fibrous or granular powder, white to slightly off-white in color, and practically odorless and tasteless.
Low ash content
As METOLOSE® is a nonionic organic compound; it can be completely combusted under appropriate burning conditions. It can also be effectively purified by washing, so its ash content is very low.
Although METOLOSE® is insoluble in hot water, it is soluble in cold water, giving a transparent viscous solution.
An aqueous solution of METOLOSE® gels or forms a precipitate when heated to a certain temperature, but it reverts to the clear solution state on subsequent cooling. The thermal gelation/precipitation temperature depends onthe substitution type, concentration, and heating rate.
Resistant to salting out
METOLOSE® is non-ionic and is not a polyelectrolyte. An aqueous solution of METOLOSE® is relatively stable in the presence of inorganic salts or organic electrolytes. However, when the concentration of electrolyte exceeds a certain limit, gelation or precipitation may occur.
Stable over a wide pH range
The viscosity of METOLOSE® solution is hardly affected by acid or alkali, and is stable at pH 3-11. However, the viscosity tends to decrease during prolonged storage of a solution under acidic or alkaline conditions.
Soluble in some organic solvents
Owning to the presence of relatively hydrophobic met Methoxy hydroxypropoxy groups, METOLOSE® is soluble in some organic solvents and also in water-organic solvent mixtures.
An aqueous solution of METOLOSE® has a high surface activity and functions as a protective colloid agent and a stabilizer for emulsions, suspensions, or foam.
METOLOSE® provides strong, flexible and transparent films with a good barrier property against oils.