Effect of 2-Hydroxypropyl-β-cyclodextrin on Solubility of Sparingly Soluble Drug Derivatives of Anthranilic Acid

Abstract

Guest-host complex formation of three drug derivatives of anthranilic acid, mefenamic acid, niflumic acid, and flufenamic acid with 2-hydroxypropyl-β-cyclodextrin (2HP-β-CD) in aqueous solutions was investigated using “Phase solubility study” with UV-vis spectrophotometry. Solubility of sparingly soluble drugs has been improved by addition of 2HP-β-CD at two temperatures 298.15 K and 310.15 K and two pH values 2 and 7. The influence of different 2HP-β-CD concentration on solubility of drugs at different pH and temperatures has been investigated. The 2HP-β-CD-drug complex stability constants (Ks), and dissociations constants (Kd), as well as the thermodynamic parameters of reaction, i.e., the free energy change (ΔG), the enthalpy change (ΔH) and the entropy change (ΔS), were determined. The experimental data indicated formation of 1:1 inclusion complexes, which were found effective binders increasing the solubility of drugs.

Synthesis and Characterization of Nano‐Encapsulated Black Pepper Oleoresin using Hydroxypropyl Beta‐Cyclodextrin for Antioxidant and Antimicrobial Applications

“…For the thermodynamic properties (Table ), the negative enthalpy values indicate that the interaction processes between BPO and HPBCD are exothermic reaction and its relatively small value (–9.9 kJ/mol) is typical of low‐energy interactions, such as hydrophobic interactions due to the displacement of water molecules from the cyclodextrin cavity, increase of van der Walls interactions between the molecules, hydrogen bonds formation, among others (Mourtzinos and others ). The positive value of entropy (53 J/mol K) indicates that van der Waal's interaction played a more important role to complex formation with HPBCD and BPO as observed by Domanska and others () and Chadha and others () with different compounds. Moreover, a relatively high Δ H value in comparison to low positive Δ S value indicates that favorable enthalpy brought about by structural tightening is only partially compensated for by a more unfavorable entropy (Chadha and others ).…”

Formulation Development to Enhance the Solubility of Metoclopramide Base Drug by Solid Dispersion and Evaluation of Transdermal Film

“…Stability constant is lowered with the decreased of pH in (pH 7.4>pH 5.5) each system. The degree of dissociation of MET increases with the decrease of pH so the Kc value decreases in acidic pH due to less interaction between ligand and guest molecules 9 .…”

Poly(ethylene glycol) brush-b-poly(N-vinylpyrrolidone)-based double hydrophilic block copolymer particles crosslinked via crystalline α-cyclodextrin domains

“…For this reason, the a-CD crosslinked linear-brush PVP 24k -b-POEGMA 13k particles were treated with anthranilic acid (AA) as a competitive guest compound for a-CD. AA shows a high affinity towards a-CD, 60 while it is a natural product and sometimes referred to as vitamin L 1 . However, aer adding AA to a 2.0 wt% DHBC solution containing 4.0 wt% of a-CD, decrosslinking can be observed ( Fig.…”