Host–guest inclusion complex of mesalazine and β‐cyclodextrin and spectrofluorometric determination of mesalazine

Abstract

The supramolecular interaction of mesalazine (MSZ) and β-cyclodextrin (β-CD) has been examined by ultraviolet-visible (UV-vis) light, infra-red (IR) light and fluorescence spectroscopy. The formation of an inclusion complex has been confirmed based on the changes of the spectral properties. MSZ-β-CD host-guest complex was formed in (1:1) stoichiometry and the inclusion constant (K = 1.359 × 10(2) L mol(-1) ) was ascertained by typical double reciprocal plots. Furthermore, the thermodynamic parameters (ΔG°, ΔH° and ΔS°) of (MSZ-β-CD) were obtained. Based on the remarkable enhancement of the fluorescence intensity of MSZ produced through complex formation, a simple, accurate, rapid and highly sensitive spectrofluorometric method for the determination of MSZ in aqueous solution in the presence of β-CD was developed. The measurement of relative fluorescence intensity was carried with excitation at 330 nm and emission 493 nm. All variables affecting the reactions were studied and optimized. Beer's law was obeyed in the concentration range 0.1-0.45 µg/mL. Absorbance was found to increase linearly with increasing concentration of MSZ, which is corroborated by the calculated correlation coefficient values of 0.99989. The molar absorptivity, Sandell's sensitivity, detection and quantification limits were calculated. The validity of the described methods was assessed, and the method was successfully applied to the determination of MSZ in its pharmaceutical formulation. In addition, a solid inclusion complex was synthesized by co-precipitation method.

Mechanism and optimization of supramolecular complexation‐enhanced fluorescence spectroscopy for the determination of SN‐38 in plasma and cells

“…The inclusion reaction was a spontaneous exothermic process due to negative free energy Δ G and negative enthalpy change Δ H . [ 40 ] Main interaction forces were van der Waals force and hydrogen bonding, therefore the inclusion process would proceed to the dissociation direction. Equilibrium constant K decreased with increasing temperature, suggesting that the lower temperature was favourable for the inclusion reaction, which was consistent with the effect of temperature on fluorescence enhancement, and which was a process of entropy reduction with negative entropy change.…”

Supramolecular interaction of gemifloxacin and hydroxyl propyl β-cyclodextrin spectroscopic characterization, molecular modeling and analytical application

“…From an analytical point of view the formation of inclusion complexes allows, to improve fluorescence intensity [7][8][9][10][11][12] and induce chiral separation in capillary electrophoresis (CE) [13][14][15]. Analysts have used this property of CDs, and many methods based on the enhanced fluorescence of the inclusion complexes with CDs were used for the determination of several pharmaceutical drugs [16][17][18][19]. Applications of supramolecular chemistry involving cyclodextrins in assay of analytes have recently been reviewed [20].…”

Luminescent properties of 4‐aminobenzo‐15‐crown‐5 after preferential binding of ferric ions in aqueous solutions

“…A combined spectroscopic approach was introduced to study the interactions of the complexes using the fluorescence quenching technique . The host–guest interactions of crown ether compounds have led to their introduction in a variety of applications, including drug inclusion . A water‐soluble fluorescent probe was applied to cell imaging .…”

“…[3] The host-guest interactions of crown ether compounds have led to their introduction in a variety of applications, including drug inclusion. [4] A water-soluble fluorescent probe was applied to cell imaging. [5] 4-Aminobenzo-15-crown-5 (4AB15C5) is known to bind metal cations such as K + , Hg 2+ , and Zn 2+ .…”