Water soluble cellulose ethers produced in Japan since 1962
Water soluble cellulose ethers
Hydroxy propyl methyl cellulose (Hypromellose) and methyl cellulose are produced by Shin-Etsu Chemical Co., Ltd. since 1960s under the trade name METOLOSE®. For methyl cellulose, several grades are available, and they differ in viscosity.
For hydroxy propyl methyl cellulose they differ in viscosity and substitution as well such as named in the pharmacopeias 2906, 2910, 2208. They are compliant with the three pharmacopeias USP (USA), JP (Japan) and EP (Europe) respectively.
The METOLOSE® product range is based on non-ionic cellulose derivatives. This property confers a good stability with a wide range of active ingredients. Furthermore, hydroxy propyl methyl cellulose (hypromellose) is a water-soluble polymer. Thus, the METOLOSE® grades available generate clear solutions once dissolved into water. Those solutions will have different viscosities depending on the amount and grade of METOLOSE® used.
Adding the METOLOSE® powder directly into cold water can be challenging, as lumps can easily be formed due to the incomplete wetting of the powder.
One method to avoid the lump formation is to take the advantage of the insolubility of hydroxyl propyl methyl cellulose in hot water (>70 °C). After cooling down, the hydroxyl propyl methyl cellulose hydrates and dissolve fully. The hydration temperature depends on the substitution grade of hypromellose. For the METOLOSE® SM types, this temperature should be below 20 °C, preferably less than 5 °C, to guaranty the full dissolution of the particles. For the METOLOSE® 60SH, 65 SH and 90SH the temperature should be below 40 °C and ideally less than 10 °C. Thus, a cooling bath is recommended for the preparation of the hypromellose solutions generally.
METOLOSE® can be dissolved in organic solvents as well. Typical examples are a combination of ethanol and water or isopropanol and water.
Properties of solutions
Hypromellose solutions are stable over a wide pH range, going from pH 3 to pH 11.
METOLOSE® consists of hydrophilic and hydrophobic groups, and thus can be considered as well as a non-ionic surfactant. This attribute provides function such as protective colloid to stabilize emulsions, suspensions or foams. The surface activity will depend on the substitution type. The lowest surface activity is obtained with the METOLOSE® grade 60SH, which makes it a good candidate for artificial tears formulations, for example.
Grades and applications
Application
Tablets & Pellets
Pellet coating
Taste masking by coating with enteric polymer and pore former
Sugar coating binder
Sustained release (matrix tablets)
Binder solution for wet granulation (WG)
Capsules
Capsule Shell
Liquid and Others
Thickening
Eye drops
Suspending
Dry syrup
Plaster/ Dermal Patch
Oral films
Continuous Manufacturing (CM) for Oral Solid Dosage Form (OSD)
The Shin-Etsu team is supporting all technical, quality and regulatory related questions. Our team of sales and technical sales manager supports you to develop your products, or during issues at your manufacturing process. Shin-Etsu has long year experience in cellulose ether business and is aiming to give you the best possible guidance and high quality products manufactured in Japan and Germany.
