Assessment of tailor-made HPMC-based matrix minitablets comprising a weakly basic drug compound.

Tailor-made, pH-controlled matrix minitablets based on different HPMC types were developed comprising the weakly basic drug dipyridamole. The incorporation of pH modifiers, i.e., fumaric and succinic acid, enhanced the drug release at pH 6.8. Assessing the drug release, acid release, and the microenvironmental pH (pHM) provided detailed understanding of pH-controlled mini-matrices. The extent and duration of pHM alteration was more pronounced in presence of fumaric acid. Minitablets based on the fast dissolving Methocel K100LV (< or = 100 cps) showed simultaneous release rates of dipyridamole and fumaric acid with a constant low average pHM.