Credo Life Science
Posted on 27th January 2022
Enteric Coated Pellets Manufacturer: How Enteric Coating Protects Drugs and Patients
Many drugs cannot survive the harsh acid of the stomach, while others irritate the stomach lining if released there. Enteric coating solves both problems by delaying release until the dosage form reaches the small intestine. When applied to pellets, enteric coating also offers the benefits of multiparticulate delivery. For formulators seeking an enteric coated pellets manufacturer, understanding the science and the quality checks involved makes it easier to choose a reliable partner.
What Is Enteric Coating?
An enteric coating is a polymer layer that stays intact in the acidic environment of the stomach and dissolves at the higher pH of the small intestine. The coating therefore prevents drug release in the stomach and allows release in the intestine, where conditions suit absorption.
Applications Beyond Proton Pump Inhibitors
Enteric-coated pellets are used for drugs that irritate the stomach, drugs that are degraded by acid and products intended to act in the intestine. Examples include certain anti-inflammatory agents, enzymes, antibiotics and bile acid preparations.
Regulatory and Pharmacopoeial Expectations
Enteric-coated products are expected to meet pharmacopoeial tests for delayed release. A typical test involves an acid stage followed by a buffer stage, with limits on drug release in each. Suppliers should be familiar with these requirements and the documentation they require.
Why Enteric-Coated Pellets?
Key advantages of multiparticulate enteric coating include:
- Protect acid-labile drugs such as proton pump inhibitors from degradation
- Reduce gastric irritation from drugs such as certain anti-inflammatory agents
- Target release to the small intestine
- Provide more uniform gastric emptying than single-unit enteric tablets
- Allow capsule filling or compression into multiple-unit tablets
- Enable combination of different release profiles in one dosage form
Common Enteric Polymers
Methacrylic Acid Copolymers & Cellulose-Based Polymers
Methacrylic Acid Copolymers: Polymers such as methacrylic acid–ethyl acrylate copolymers dissolve above specific pH values and are widely used as aqueous dispersions. Different grades dissolve at different pH levels, allowing targeting of regions of the intestine.
Cellulose-Based Polymers: Hydroxypropyl methylcellulose phthalate, hydroxypropyl methylcellulose acetate succinate and cellulose acetate phthalate are established enteric polymers with different dissolution pH thresholds and processing needs.
Plasticisers and Anti-Tacking Agents: Plasticisers such as triethyl citrate improve film flexibility, while talc or glyceryl monostearate reduces sticking during coating, especially for small pellets.
The Enteric Coating Process for Pellets
Core Quality and Sub-Coating for Acid-Labile Drugs
Starting With Quality Cores: Uniform, spherical, low-friability drug-loaded pellets are essential. Poor core quality leads to uneven coating and unpredictable release.
Sub-Coating for Acid-Labile Drugs: Many acid-labile drugs, especially proton pump inhibitors, are destabilised by the acidic groups of enteric polymers. A neutral sub-coat, also known as a barrier or seal coat, separates the drug from the enteric layer, protecting stability during manufacture and shelf life.
Fluid Bed Coating, Curing and Drying
Fluid Bed Coating: Pellets are fluidised in a bottom-spray fluid bed processor and sprayed with the coating dispersion. Parameters such as inlet air temperature, spray rate, atomisation pressure and product temperature are tightly controlled to achieve a smooth, continuous film.
Curing and Drying: After coating, the pellets are dried or cured to remove moisture and allow film formation. This step affects the integrity and release of the coating.
Quality Tests for Enteric-Coated Pellets
Standard analytical and pharmacopoeial release tests include:
- Assay and content uniformity
- Acid-resistance test, typically in acidic medium for a set period
- Buffer-stage dissolution to confirm timely release at intestinal pH
- Particle size distribution and sphericity
- Coating weight gain and film thickness
- Residual solvents and moisture content
- Accelerated and long-term stability
Failure in the acid stage is a critical defect, since it means the drug is released where it should not be, so consistent acid resistance is a key indicator of a reliable manufacturer.
Challenges in Enteric Coating
Critical technical challenges to avoid during production:
- Film cracking or defects from poor plasticisation or mechanical stress
- Pellet agglomeration during coating
- Drug–polymer incompatibility, especially with acid-sensitive APIs
- Variation in coating level across the batch
- Changes in coating performance during storage in hot, humid conditions
Selecting an Enteric Coated Pellets Manufacturer
Formulators should look for suppliers offering:
- Demonstrated experience with enteric systems and acid-labile drugs
- Fluid bed equipment suited to pellet coating
- Strong in-process controls and analytical capability
- Quality systems aligned with good manufacturing practices
- Stability data in relevant climatic conditions
- Support for technology transfer and regulatory documentation
Why Choose Credo Life Sciences?
Credo Life Sciences focuses on pharmaceutical pellets and granules for formulation companies that need consistent quality, dependable supply and clear technical communication. We understand that a multiparticulate ingredient is only as good as its reproducibility from batch to batch, so our approach centres on controlled processes, thorough documentation and responsive support for your development and commercial needs. We work as a long-term partner to our customers, not just a vendor.
Enteric-coated pellets combine intelligent coating science with multiparticulate benefits. Quality depends on core quality, the right polymers, careful process control and rigorous testing. If you are looking for an enteric coated pellets manufacturer, talk to us about your product and specifications.
Partner with Credo Life Sciences for your pellet and granule requirements. Contact our team to discuss specifications and quotations.