Hot melt extruded HPC based formulations to control drug release

Over the last five years there has been a growing interest in the capabilities of Hot Melt Extrusion (HME) for the rapid production of solid oral dosage forms to provide sustained or controlled release (1). Many of the polymers used in production form hydrogels some of which respond to temperature. At the Low Critical Solution Temperature (LCST), there is an abrupt phase transition as the hydrophobic groups align and cause the gel to collapse and shrink(2). LCST materials can force out the drug as the gel shrinks.
This study details the application of HME formulations containing Hydroxypropylcellulose (HPC) as a base polymer using a combination of Methylcellulose (MC) and Hydroxypropylmethylcellulose (HPMC). The limit to which formulation controlled drug release under varying hydrodynamic effects, high alcohol environments and high and low drug loads were investigated using.