Drug Release from Oral Matrix Tablets Containing Hypromelose

Swellable-matrix tablets based on hydrophilic polymers are simple dosage forms with controlled release, which are currently used in pharmacotherapy of many diseases. The most commonly used polymer is (hydroxypropyl)methylcellulose (hypromelose). The drug release from these systems through a gel layer can be modified using additives changing the drug dissolution profile. These excipients can be divided into several groups such as indifferent fillers (soluble or insoluble), substances increasing drug solubility (P-cyclodextrins), excipients forming interactive products (polymers, ion-exchange resins, surfactants) and substances influencing pH in matrix microenvironment (acid and basic modifiers).