Overview
Hypromellose
Hydroxypropyl methylcellulose is a nonionic, water-soluble cellulose ether derived from short cotton linters (wood pulp). The cellulose is hydrolyzed with sodium hydroxide to produce alkaline cellulose, which is then etherified at high temperature with a mixture of methyl chloride and propylene oxide. Cellulose is insoluble in water because of the strong intermolecular hydrogen bonding between the hydroxyl groups in its crystal structure. When some of the hydroxyl hydrogen atoms are replaced by methyl or hydroxypropyl groups, the resulting methoxy and hydroxypropoxy groups interfere with the intermolecular hydrogen bonding, thereby reducing the bonding strength between the polymer chains and making the polymer water-soluble.
This product is made by treating refined cotton (cotton linter, cotton pulp) or wood pulp (wood pulp) with caustic soda, reacting with methyl chloride and propylene oxide in succession, refining and crushing to obtain cellulose ether with a molecular weight range of 10,000 - 150,000.
Chemical name: 2-Hydroxypropyl ether methyl cellulose
Structural formula:
Where R=H、CH
3 or CH
3CH(OH)CH
2
Properties
It is a white or off-white fibrous or granular powder. It is almost insoluble in anhydrous ethanol, ether or acetone; it swells into a clear or slightly turbid colloidal solution in cold water.
pH: The pH value of 2% aqueous solution at 20°C±2°C is 5.0~8.0.
Auto-ignition temperature: 360°C.
Melting point: Brown at 190-200°C; charred at 225-230°C.
Controlled release products
Sustained-release preparations control drug release through a gel layer, which is formed by the hydration of HPMC. The formulation is simple and basically consists of the drug and HPMC. Therefore, the dissolution profile can be controlled by selecting a specific type of HPMC. Compared with polymer-coated controlled release, the dissolution of matrix tablets is very stable because it can be controlled by the formulation. However, the selection and quality of HPMC are very important. The solubility of HPMC particles in the tablet is also an important aspect of gel formation, and the hardness of the tablet directly affects the appearance of the product and the formation of the gel layer. If the gel layer is hydrated for too long, local disintegration will occur, resulting in deviations in dissolution. Therefore, the specific gravity and particle size of the product can further control swelling and disintegration.
Coating products
Film-coated tablets were introduced in the 1970s. Since then, a large number of studies have been conducted to improve the productivity of film-coated tablets, save costs, improve pharmaceutical production efficiency and drug bioavailability. Today, film coating has become a mature and efficient technology. It is crucial for film coating to select the appropriate viscosity and concentration according to the requirements of use to prepare the viscosity of the coating. At the same time, it is necessary to add a certain amount of plasticizer to offset the effect of some covering agents, lubricants, etc. on the strength of the coating. Coating has a positive effect on product stability, appearance recognition, taste masking and coloring, and preventing the finished product from reacting with other functional layers.
Vegetable capsules
The hollow capsules prepared with hydroxypropyl methylcellulose as the main raw material have the advantages of stable properties, not being brittle under low humidity conditions, being able to maintain the stability of the capsule shell under high humidity conditions, having wide storage conditions, and not requiring the addition of any preservatives during the production process.
Gel
Hydroxypropyl methylcellulose can be used as an aqueous gel matrix, and products of different viscosities can be selected to adjust the consistency of the product according to different requirements of gel production.
Specifications
Divided into type 2910 and type 2208.
|
Replacement Type
|
Images
|
Methoxy content (%)
|
Hydroxypropoxy content (%)
|
Screening rate
|
Typical Applications
|
|
2910
|
|
28.0-30.0
|
7.0-12.0
|
100 mesh ≥99.5%
|
Coating, bonding, thickening
|
|
|
27.0-30.0
|
Vegetable capsules
|
|
2208
|
|
19.0-24.0
|
4.0-12.0
|
Thickening, sustained-release matrix
|
|
21.0-24.0
|
8.0-12.0
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Customized according to the target
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Customized sustained release skeleton
|
Indicators
Conforming to Standards: ChP (Chinese Pharmacopoeia), USP (United States Pharmacopoeia),
EP (European Pharmacopoeia)
|
Item
|
Specification
|
|
Model 2910
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Model 2906
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Model 2208
|
|
Methoxy(%)
|
28.0-30.0%
|
27.0-30.0%
|
19.0-24.0%
|
|
Hydroxypropoxy(%)
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7.0-12.0%
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4.0-7.5%
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4.0-12.0%
|
|
PH
|
5.0-8.0
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|
Insoluble Matter in Water
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≤5mg(0.5%)
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Loss on Drying(%)
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≤5.0%
|
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Residue(%)
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≤1.5%
|
|
Heavy Metals(ppm)
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≤10ppm
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Arsenic (ppm)
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≤0.0002%
|
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Microbiological Limit
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Total microbe count≤1000cfu/g
Total mold and yeast≤100cfu/g
Escherichia coli not detected
|
Conform to the standard: National Food Safety Standard, Food Additive, Hypromellose (HPMC) GB1886.109
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Item
|
Index
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Test Method
|
|
Methoxy（-OCH₃）Content，w/%
|
19.0-30.0
|
Appendix A, A.4
|
|
Hydroxypropoxy（-OCH₂CHOHCH₃）Content，w/%
|
3.0-12.0
|
Appendix A, A.4
|
|
Loss on drying，w/%
|
≤5.0%
|
GB5009.3adirect drying method
|
|
Residue，w/%
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Viscosity≥50mPa.s
|
≤1.5
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GB/T 9741
|
|
Viscosity＜50mPa.s
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≤3.0
|
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Viscosity / (mPa.s)
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Viscosity≤100mPa.s
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80.0%~120.0% of the declared value
|
AppendixA, A.5
|
|
Viscosity＞100mPa.s
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75.0%~140.0% of the declared value
|
|
Lead（Pb）/(mg/kg)
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≤3.0
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GB5009.12
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Drying temperature is 105℃±2℃, and drying time is 2h
Indicated viscosity and range
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Indicated Viscosity
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Range（mPa.s）
|
|
3
|
2.5-3.5
|
|
4
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3.6-4.5
|
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5
|
4.6-5.5
|
|
6
|
5.6-7.2
|
|
10
|
8.0-12.0
|
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15
|
12.1-18.0
|
|
30
|
24.0-36.0
|
|
50
|
40.0-60.0
|
|
100
|
80.0-120.0
|
|
4000
|
3000-5600
|
|
15000
|
11250-21000
|
|
100000
|
75000-140000
|
|
200000
|
150000-280000
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