A pharmaceutical dosage form such as a capsule, a conventional or orallydisintegrating tabletcapable of delivering a nitrogen (N)-containing therapeutic agent having a pKain the range offrom about 5 to 14 into the body in a sustained- released fashion, in order tobe suitable for atwice- or once-daily dosing regimen, comprises at least one organic acid,which solubilizes thetherapeutic agent prior to releasing it into the hostile intestinalenvironment wherein said weaklybasic drug is practically insoluble. The unit dosage form is composed of amultitude ofmulticoated particulates (i.e., immediate-release beads, sustained- releasebeads and/or one ormore timed, pulsatile-release bead populations) and is designed in such a waythat said weaklybasic drug and said organic acid do not come into close contact duringprocessing and/or storagefor in-situ formation of acid addition compounds while ensuring that the acidis not depletedprior to completion of the drug release.
