title: External electrostatic interaction versus internal encapsulation between cationic dendrimers and negatively charged drugs: which contributes more to solubility enhancement of the drugs?
abstract: Relationships of electrostatic interaction and encapsulation between poly(amidoamine) (PAMAM) dendrimers and negatively charged drug molecules have been investigated by aqueous solubility and NMR ( (1)H NMR and two-dimensional nuclear Overhauser effect spectroscopy (2D-NOESY)) studies. PAMAM dendrimers significantly increased the solubilities of phenobarbital and sulfamethoxazole, but scarcely influenced those of primidone and trimethoprim. Moreover, (1)H NMR and 2D-NOESY measurements indicated that few phenobarbital or sulfamethoxazole molecules were entrapped in the cavities of low-generation dendrimers (generation 3, G3). These results suggest that external electrostatic interaction contributes more to the solubility enhancement of drugs than internal encapsulation.
authors.affiliation: Laboratory of Functional Membranes, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, China. yycheng@mail.ustc.edu.cn
authors.forename: Yiyun
authors.initials: Y
authors.lastname: Cheng
authors.forename: Qinglin
authors.initials: Q
authors.lastname: Wu
authors.forename: Yiwen
authors.initials: Y
authors.lastname: Li
authors.forename: Tongwen
authors.initials: T
authors.lastname: Xu
mesh_terms: D050091:Dendrimers / Q000737:chemistry*; D006860:Hydrogen Bonding; D057927:Hydrophobic and Hydrophilic Interactions; D009682:Magnetic Resonance Spectroscopy; D004364:Pharmaceutical Preparations / Q000737:chemistry*; D011073:Polyamines / Q000737:chemistry; D012995:Solubility; D055672:Static Electricity; D014867:Water / Q000737:chemistry
chemical_list: D050091:Dendrimers; D004364:Pharmaceutical Preparations; D011073:Polyamines; D014867:Water