Performance of multilayered particles: influence of a thin cushioning layer

Area of Science:

• Pharmaceutical Technology
• Materials Science
• Drug Delivery Systems

Background:

• Controlled release oral dosage forms are increasingly important.
• Polymer coating of drug particles is a common method for controlling drug release.
• Coating integrity is often compromised during tablet compression, altering drug release.

Purpose of the Study:

• To investigate the impact of a HydroxyPropylMethyl Cellulose (HPMC) cushioning layer on coated theophylline particles.
• To assess the effects on particle characteristics, tablet properties, and dissolution performance.
• To understand how HPMC cushioning influences coating integrity and drug release during compression.

Main Methods:

• Coating theophylline particles with a polymer.
• Applying a thin HydroxyPropylMethyl Cellulose (HPMC) cushioning layer.
• Compressing coated particles into tablets.
• Evaluating particle characteristics, tablet properties (e.g., cohesiveness), and drug release profiles.

Main Results:

• The HPMC cushioning layer did not significantly affect particle characteristics.
• Tablet cohesiveness was reduced due to the cushioning effect of HPMC.
• The theophylline release rate increased, attributed to HPMC's water-solubility and channel formation.
• The cushioning layer protected polymer coats from fracture during compression.

Conclusions:

• A thin HPMC cushioning layer effectively protects polymer coats from damage during tablet compression.
• While protecting coats, the HPMC layer can increase drug release rates due to its properties.
• Both the protective effect on coating integrity and the impact on drug release must be evaluated for such drug delivery systems.