TY - JOUR
T1 - Self‐association of dexverapamil in aqueous solution
AU - Surakitbanharn, Yosyong
AU - McCandless, Richard
AU - Krzyzaniak, Joseph F.
AU - Dannenfelser, Rose‐Marie ‐M
AU - Yalkowsky, Samuel H.
N1 - Funding Information:
Chemistry, University of Arizona, and Professor Bradley Anderson from the Department of Pharmaceutics and Pharmaceutical Chemistry, University of Utah, for their valuable comments and suggestions. We also thank Knoll Pharmaceutical Company and Glaxo Inc. for their financial support.
PY - 1995/6
Y1 - 1995/6
N2 - 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.
AB - 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.
UR - https://www.scopus.com/pages/publications/0028998019
UR - https://www.scopus.com/pages/publications/0028998019#tab=citedBy
U2 - 10.1002/jps.2600840611
DO - 10.1002/jps.2600840611
M3 - Article
C2 - 7562411
AN - SCOPUS:0028998019
SN - 0022-3549
VL - 84
SP - 720
EP - 723
JO - Journal of pharmaceutical sciences
JF - Journal of pharmaceutical sciences
IS - 6
ER -