Self‐association of dexverapamil in aqueous solution

Yosyong Surakitbanharn, Richard McCandless, Joseph F. Krzyzaniak, Rose‐Marie ‐M Dannenfelser, Samuel H. Yalkowsky

Research output: Contribution to journalArticlepeer-review

23 Scopus citations


The pKa and intrinsic solubility of monomeric dexverapamil were determined from its pH–solubility profile to be 8.90 and 6.6 × 10−5 M, respectively. The solubility of dexverapamil below pH 7.0 was higher than expected on the basis of the aforementioned values. This unusually high solubility is believed to be due to the self‐association of cationic dexverapamil. The apparent pKa of the self‐associated drug is estimated to be ∼7.99. The self‐association of dexverapamil hydrochloride is supported by the fact that it is surface active and that it increases the solubility of both naphthalene and anthracene in aqueous solutions. The dependence of the drug solubility on pH and the solubilization of naphthalene and anthracene as a function of ionized drug concentration suggest that the self‐associated dexverapamil is a cationic dimer.

Original languageEnglish (US)
Pages (from-to)720-723
Number of pages4
JournalJournal of pharmaceutical sciences
Issue number6
StatePublished - Jun 1995

ASJC Scopus subject areas

  • Pharmaceutical Science


Dive into the research topics of 'Self‐association of dexverapamil in aqueous solution'. Together they form a unique fingerprint.

Cite this