Stoichiometry and Thermodynamic of Inclusion Complexation Between Zaleplon and Hydrophilic Cyclodextrin Derivatives

摘要: The objective of this paper was to determine the thermodynamic parameter zaleplon (ZAL) complexation with a series cyclodextrins (CDs) aimed improve solubility and bioavailability poorly soluble hypnotic agent. This knowledge is important since it would allow determination critical parameters affecting drug affinity obtain more general understanding driving forces behind such inclusion phenomena. essential for further method development complex preparation in solid state could help develop novel CD derivatives superior properties specific class drugs. list CDs used comprised natural s-cyclodextrin (sCD) its hydrophilic (HPsCD, RAMEB SBEsCD). To system studied, fluorescence nuclear magnetic resonance (1H-NMR) used. stoichiometry complexes formed obtained from 1H-NMR data using continuous variation (Job’s plot) by statistical analysis spectrofluorimetric titration data. results confirmed formation equimolar all cases, excluding possibility higher order formation. Thermodynamic both methods gave similar negative values ∆G^0 complexes, indicating spontaneous ZAL into CDs. From point view, two types inclusions were determined. One enthalpy driven sCD, HPsCD RAMEB, while other entropy observed case SBEsCD. mechanisms each type discussed details.