An Investigation on the Effect of Polyethylene Oxide Concentration and Particle Size in Modulating Theophylline Release from Tablet Matrices.

Polyethylene oxide has been researched extensively as an alternative polymer to hydroxypropyl methylcellulose (HPMC) in controlled drug delivery due to its desirable swelling properties and its availability in a number of different viscosity grades. Previous studies on HPMC have pointed out the importance of particle size on drug release, but as of yet, no studies have investigated the effect of particle size of polyethylene oxide (polyox) on drug release. The present study explored the relationship between polymer level and particle size to sustain the drug release.

Psyllium: a promising polymer for sustained release formulations in combination with HPMC polymers.

Psyllium has a mucilaginous property that makes it a good candidate to be utilized as an excipient in the preparation of controlled release systems. Various formulations were prepared using theophylline as a model drug and investigated with a view to achieve an ideal slow drug release profile. The addition of hydroxypropyl methylcellulose (HPMC) to psyllium significantly reduced the burst release; however, the percentage of drug release within a 12 h period was too slow and thereby inadequate.