Effect of hydroxypropyl-beta-cyclodextrin and pH on the solubility of levemopamil HCl.
Levemopamil was solubilized by varying the concentration of hydroxypropyl-beta-cyclodextrin (HPbetaCD) and by the alteration of pH. The drug molecule has two sites for possible complexation with HPbetaCD, creating the possibility of either 1:1 or 1:2 complexation. The solubility as a function of HPbetaCD concentration of the charged and uncharged forms of the drug follows the A(L) and Ap complexation models, respectively. This suggests that the charged drug forms a 1:1 complex, whereas the neutral drug forms both 1:1 and 1:2 complexes.
McCandless
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Department of Pharmaceutical Sciences, University of Arizona, College of Pharmacy, Tucson 85721, USA.
Yalkowsky
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D000073738:2-Hydroxypropyl-beta-cyclodextrin; D002121:Calcium Channel Blockers / Q000737:chemistry*; D003505:Cyclodextrins / Q000494:pharmacology*; D004355:Drug Stability; D006863:Hydrogen-Ion Concentration; D015394:Molecular Structure; D012995:Solubility; D014700:Verapamil / Q000031:analogs & derivatives* / Q000737:chemistry; D047392:beta-Cyclodextrins
D002121:Calcium Channel Blockers; D003505:Cyclodextrins; D047392:beta-Cyclodextrins; D000073738:2-Hydroxypropyl-beta-cyclodextrin; D014700:Verapamil; C052752:emopamil