CAS No: 9004-65-3
EINECS No.: 220-971-6
H.S CODE:: 391290000
Hydroxypropyl methylcellulose (HPMC) is a semisynthetic, viscoelastic polymer, it is a cellulose ether.Hydroxypropylmethyl cellulose (HPMC) can be dissolved into some organic solvents and also in water-organic solvent mixed solvents. it does not have a gelation property when heated. HPMC is a is non-toxic to humans the raw material from cotton and wood.
Hydroxypropyl methylcellulose (HPMC) is hygroscopic after drying but stable. Its solution is stable at pH 3-11. As the temperature increases, the viscosity of the solution decreases. Heating-cooling can reversibly convert HPMC from a solution state to a gel state. According to different grades and concentrations, the gelation temperature is 50 ～ 90 ℃. HPMC aqueous solution has anti-enzyme effect and maintains good viscosity stability during long-term storage. However, its aqueous solution is susceptible to attack by microorganisms, so preservatives should be added during storage. When HPMC is used as a thickener in ophthalmic eye drops, benzalkonium chloride is usually added as a preservative.
|Methoxyl Content (wt%)||28-30|27-30|19-24||
|Hydrooxypropoxyl Content (wt%)||4-12|
|Gelling Temperature (°C)||58-90|
|Loss on drying (wt%)||5 max|
|Ash||1% max (by weight)|
|PH (25 °C)||4-8|
|Chloride (NaCl))||0.2% max|
|Arsenic (ppm)||2 max|
|Heavy metal (ppm)||20 ppm max|
|Apparent Viscosity (2% solution, 20°C , mpa.s)||5-100000|
1) in 25KG net weight fiber drums lined with PE bags
2) in 25KG paper bags.
1. Dissoving in hot water: This method takes advantage of the insolubility of HPMC in hot water.
a). Place the required volume of hot water heated to 70℃ or above into a vessel. Gradually add the HPMC while stirring. At first HPMC floats on the surface of the hot water, but it will gradually disperse to form uniform slurry. Cool down the resultant mixture while stirring until it becomes transparent.
b). Place about 1/3 to 2/3 of the required volume of water into a vessel and heat to about 70℃. Then disperse the HPMC and prepare the hot water slurry according to method a). Add the remainder of the water as cold water or ice water while stirring to lower the temperature of the dispersion. Cool down the resultant mixture while stirring until it becomes transparent.
2. Powder mixing method： This method can be applied when water-insoluble ingredients are used with HPMC. Mix both the HPMC powder and water insoluble ingredients together in advance at the ratio of 1: more than 3 (volume) and blend the dry components thoroughly. Add water to the dry mixture and mix it by agitation. Atthis time HPMC can be dissolved without lumping.
3. Organic solvent wetting method： Disperse or wet the HPMC powder in alcohol or glycol in advance, and then add water to the dispersion while stirring until it dissolves completely