Drug release from MCC- and carrageenan-based pellets: experiment and theory

Area of Science:

• Pharmaceutical Technology
• Drug Delivery Systems
• Materials Science

Background:

• Microcrystalline cellulose (MCC) is a common pelletisation aid but leads to prolonged drug release, particularly for poorly soluble drugs.
• This characteristic limits its use for immediate-release formulations.

Purpose of the Study:

• To modify prolonged drug release from MCC pellets using disintegrants (croscarmellose Na) or pore formers (PEG 6000).
• To assess carrageenan as an alternative pelletisation aid for high-dose, immediate-release pellets.
• To elucidate drug release mechanisms from these pellet formulations.

Main Methods:

• Pellets containing 77-90% drug (vatalanib succinate, SAG/ZK, or theophylline) were prepared via extrusion-spheronisation.
• Drug release kinetics were analyzed using Fick's law.
• Physical properties like yield, aspect ratio, tensile strength, and porosity were evaluated.

Main Results:

• MCC pellets exhibited release controlled by diffusion and drug solubility, quantifiable by Fick's law.
• Addition of disintegrants or pore formers effectively modulated drug diffusivity and release times (minutes to hours).
• Carrageenan pellets rapidly disintegrated, releasing high drug doses quickly.

Conclusions:

• Drug release from MCC pellets can be precisely controlled by incorporating disintegrants or pore formers.
• Carrageenan is a viable alternative for developing rapid disintegration, immediate-release pellets for poorly soluble drugs.
• Understanding diffusion mechanisms is key to optimizing drug release profiles.