Mechanical properties of single pellets containing acrylic polymers

Area of Science:

• Pharmaceutical Technology
• Materials Science

Background:

• Acrylic latex dispersions are used as binders in pellet formulations.
• Understanding pellet mechanical properties is crucial for drug delivery.

Purpose of the Study:

• To investigate the influence of aqueous-based acrylic latex binders on the mechanical properties of microcrystalline cellulose and anhydrous lactose pellets.
• To determine the effect of polymer type, concentration, plasticizer, and particle size on pellet strength.

Main Methods:

• Pellets were prepared using extrusion-spheronization with Eudragit L 30 D, NE 30 D, and RS 30 D as binders.
• Mechanical properties (tensile strength, Young's modulus) were measured using a tension/compression tester.
• Influence of particle size and plasticizer on Eudragit RS 30 D pellets was assessed.

Main Results:

• Pellets exhibited brittle fracture under compression.
• Mechanical strength was governed by polymer-particle adhesion, not polymer cohesion.
• Polymer type, concentration, plasticizer, and particle size significantly impacted Young's modulus and tensile strength.
• Binder properties and plasticizer affected granule processability during spheronization.

Conclusions:

• Pellet mechanical strength is primarily dependent on the adhesive bond between the acrylic binder and powder particles.
• Formulation parameters like polymer choice, plasticizer addition, and particle size are critical for controlling pellet mechanical properties and manufacturing behavior.