Effect of formulation composition on the properties of controlled release tablets prepared by roller compaction.

This study discusses the effect of formulation composition on the physical characteristics and drug release behavior of controlled-release formulations made by roller compaction. The authors used mixture experimental design to study the effect of formulation components using diclofenac sodium as the model drug substance and varying relative amounts of microcrystalline cellulose (Avicel), hydroxypropyl methylcellulose (HPMC), and glyceryl behenate (Compritol). Dissolution studies revealed very little variability in drug release.

The use of mixer torque rheometry to study the effect of formulation variables on the properties of wet granulations.

Mixer torque rheometry was used to investigate the rheological behavior of wet granulations with different concentrations of drug, binder, and water. An experimental design was employed to systematically study the effects of the three formulation variables on the torque profiles of the wet masses over time. Under comparable conditions, increasing binder and water concentrations tended to produce higher wet mass consistencies.

Investigation of potential ionic interactions between anionic and cationic polymethacrylates of multiple coatings of novel colonic delivery system.

The objective of this work was to investigate potential interactions between anionic (Eudragit FS) and cationic (Eudragit RL) polymethacrylates of multiple coatings of a novel colonic drug delivery system. Aqueous films of pure polymers Eudragit FS (FS) and Eudragit RL (RL) and their superimposedfilm (FS-RL) were cast on glass slabs. The potential ionic interactions were studied by analysing the dried films using differential scanning calorimetry (DSC), Fourier transform-infrared spectroscopy (FT-IR), and nuclear magnetic resonance (NMR).