Pellet-based systems provide a robust and flexible platform for addressing the formulation challenges of modern APIs. When combined with a well-controlled functional coating system, they enable reliable performance from development to commercial manufacturing.
Oral Solid Dosage Forms (OSDFs), such as tablets and capsules, are a standard in pharmaceutical delivery due to their robustness, scalability, and patient acceptance. However, the increasing prevalence of complex New Chemical Entities (NCEs) including highly potent APIs (HPAPIs), moisture-sensitive compounds, and poorly soluble molecules continues to challenge conventional formulation approaches.
In response, Multi-Unit Pellet Systems (MUPS) have become an established platform in advanced oral dosage design. Pellets are small, free-flowing particles (typically 100–1500 μm), produced via techniques such as extrusion–spheronization. Their uniformity and modular structure enable precise control of drug release and dosing performance.
Formulating for modern API challenges
Many contemporary APIs present formulation constraints such as:
• Limited aqueous solubility affecting bioavailability
• Sensitivity to moisture, light, or oxidation
• Narrow therapeutic windows requiring high dose precision
• Need for taste masking or modified release profiles
Pellet-based systems provide a structured approach to managing these challenges through controlled particle engineering and functional coating strategies.
Key advantages of pellet technology
From a formulation and manufacturing perspective, pellets offer several well-established benefits:
• Predictable pharmacokinetics through uniform particle distribution and reliable gastrointestinal transit
• High dose accuracy, supported by narrow size distribution and consistent coating behaviour
• Flexible release design, enabling immediate, delayed, or sustained release profiles
• Improved stability, where core design can help protect sensitive APIs from environmental stress factors
Practical relevance in formulation design
Pellet systems are particularly relevant in applications such as acid-sensitive APIs requiring gastro-resistant protection and in low-dose, high-potency compounds where uniformity is critical. They are also well-suited for formulations requiring taste masking, including paediatric applications and modified-release systems requiring precise kinetic control.
Downstream processing considerations
While pellets offer strong formulation advantages, downstream processing such as encapsulation or compression into MUPS tablets, introduces mechanical and physical stresses that can affect product performance. Key parameters such as pellet size, shape, and density play a central role in flowability and dosing accuracy, resistance to mechanical stress during tableting and prevention of segregation and content variability.
Maintaining pellet integrity throughout processing is therefore essential for consistent final product quality. This can be achieved with a functional coating that provides both stability and process reliability such as SEPIFILM LP.
SEPIFILM™: Functional coating for pellet protection
SEPIFILM™ ready-to-use coating system is designed to support both manufacturing efficiency and functional performance in pellet-based dosage forms. It contributes to process stability, mechanical protection, and consistent product quality which are all key parameters in the development of advanced oral solid dosage forms.
Process and handling benefits:
• Simplified preparation and reduces batch variability
• Uniform film formation across fluid bed and pan coating systems
• Improved flow properties through reduced surface friction and electrostatic effects
• Consistent visual appearance and controlled colour masking
Protection of pellet integrity
• Mechanical protection during handling, blending, and compression
• Barrier against moisture and chemical interaction
• Preservation of functional release profiles in modified-release systems
Validated process conditions demonstrate consistent performance across pellet sizes and formulation viscosities when spray parameters are appropriately controlled.
SEPIFILM performance in MUPS formulations
Seppic has conducted an R&I study assessing SEPIFILM LP performance in MUPS formulations, focusing on parameters like enhanced flow, mechanical shield and process reliability.
