What material is used to make HPMC hollow capsules?

HPMC hollow capsules are made of hydroxypropyl methylcellulose (HPMC) with appropriate excipients, and their core materials and process characteristics are as follows:

1, Core materials

Hydroxypropyl methylcellulose (HPMC)

Source: Made from natural plant fibers (such as short cotton and wood pulp) through etherification modification, it belongs to cellulose derivatives.

Characteristics:

Chemical inertness: does not undergo cross-linking or Maillard reactions with drugs, avoiding drug spoilage.

High stability: Under normal conditions, it will not decompose or deteriorate after being stored for a long time. It has low moisture requirements for the filling material and is suitable for filling drugs with strong moisture properties.

Good biocompatibility: Listed as a safe material (GRAS certified) by FDA, EU, and Chinese Pharmacopoeia, with no daily dosage limit, suitable for vegetarians and special faith populations.

accessories

Plasticizers such as glycerol and polyethylene glycol 400 enhance the flexibility of capsules and prevent brittle cracking.

Sunscreen agent: such as titanium dioxide (0.5% -2%), enhances the capsule's protection against photosensitive drugs.

Pigments: Natural or synthetic pigments (compliant with food grade standards) used to distinguish specifications or brands.

Lubricant: such as magnesium stearate (0.1% -0.5%), reduces mold friction and ensures smooth molding.

2, Material ratio and process control

Basic formula

HPMC accounts for 85% -95%, plasticizer 3% -10%, and the balance is water.

Dissolve by high-speed shearing emulsifier or colloid mill, with temperature controlled at 60-80 ℃ and time of 2-4 hours, to ensure the transparency and absence of particles in the gel solution.

The viscosity target value is 5000-15000mPa · s (25 ℃), monitored by a Brookfield viscometer.

forming process

Dip molding: Preheat the mold to 40-50 ℃, immerse it in the glue solution and slowly remove it to form a uniform glue film.

Rotary drying: Dry in hot air at 30-40 ℃ for 10-15 minutes, repeat 2-3 times to control wall thickness (0.08-0.15mm) and weight (e.g. 0 # capsule about 0.12g/capsule).

Demoulding and cutting: Demoulding is carried out through high-pressure gas or mechanical devices, and cut into standard lengths (such as 23.3mm ± 0.3mm).

critical control point

Gel temperature: Too high can cause poor fluidity, while too low can easily generate bubbles.

Dry environment: The humidity should be controlled at 30% -40% to avoid moisture absorption and deformation of the capsules.

Impurity residue: Dry weight loss ≤ 8%, transparent residue on ignition ≤ 3%, semi transparent residue ≤ 5%, opaque residue ≤ 9%, heavy metal content ≤ 20ppm.

3, Material advantages

safety

No animal derived ingredients, avoiding the risk of animal diseases such as mad cow disease, and complying with vegetarian, halal, and Jewish dietary standards.

Strict microbial limits (total aerobic bacteria ≤ 10 ³ CFU/g, mold/yeast ≤ 10 ² CFU/g) ensure the hygiene and quality of drugs.

functionality

Low humidity stability: moisture-proof and mold proof, reducing the risk of drug mold and deterioration.

Controllable drug release performance: rough surface, high affinity with enteric coating materials, better coating uniformity than gelatin capsules, lower gastric permeability, and more precise intestinal release.

Strong adaptability: It can be filled with wet drugs, hygroscopic powders or liquids to avoid capsule rupture or drug degradation.

environmental friendliness

The raw materials are renewable, and there are no organic solvent emissions during the production process, which is in line with the trend of green manufacturing.

Some products use biodegradable HPMC derivatives to further enhance their environmental performance.