Formulation and evaluation of mefenamic acid sustained release matrix pellets

Area of Science:

• Pharmaceutical Technology
• Drug Delivery Systems
• Materials Science

Background:

• Sustained release formulations aim to prolong drug action and improve patient compliance.
• Mefenamic acid (MA) is a nonsteroidal anti-inflammatory drug (NSAID) commonly used for pain and inflammation.
• Developing effective sustained-release matrix pellets requires careful control over formulation parameters.

Purpose of the Study:

• To prepare mefenamic acid (MA) sustained-release matrix pellets.
• To investigate how formulation parameters influence pellet attributes and in vitro drug release.
• To correlate wet mass rheology with pellet characteristics and drug release performance.

Main Methods:

• Mefenamic acid pellets were prepared using extrusion/spheronization with microcrystalline cellulose (MCC) and lactose.
• A mixer torque rheometer (MTR) characterized the wet mass rheological properties.
• Pellet particle size and in vitro drug dissolution were evaluated.
• The effect of varying lactose:MCC ratios and polyvinyl pyrrolidone (PVP) addition was studied.

Main Results:

• Increased lactose ratio to MCC reduced maximum torque and binder requirements.
• Polyvinyl pyrrolidone (PVP) addition affected mean torque but not wetting liquid amount.
• Pellet particle size ranged from 945-1089 µm with small span values (0.56-0.67).
• Higher mefenamic acid loading (2.5-10%) decreased dissolution rates.
• A significant inverse relationship was found between wet mass peak torque and in vitro release rate.

Conclusions:

• Mefenamic acid (MA) sustained-release matrix pellets can be successfully prepared.
• Controlling wet mass characteristics, measured by torque, allows effective monitoring of pellet properties.
• Rheological properties of the wet mass are critical determinants of pellet quality and drug release performance.