Freeze dried multicomponent inclusion complexes of quercetin: Physicochemical evaluation and pharmacodynamic study

Abstract

The present study was undertaken to investigate the effect of cyclodextrin (CD) complexation in presence of hydrophilic polymer on physicochemical properties as well as anti- inflammatory activity of quercetin (QUN). The initial phase solubility studies were carried out in presence and absence of hydrophilic polymers (hydroxypropylmethylcellulose, polyvinylpyrrolidone K30 and poloxamer 188) to study their effect on the stability and complexation efficiency of CDs. The binary (QUN-βCD and QUN-HPβCD) and multicomponent (QUN-βCD-POLO and QUN-HPβCD-POLO) inclusion complexes of QUN prepared using lyophilization technique. The complexes were subjected to DSC, ATR-FTIR, XRPD and SEM analysis, and evaluated for drug content and saturation solubility. The phase solubility studies revealed the formation of QUN-βCD and QUN-HPβCD complexes with 1:1 stoichiometry. The incorporation of POLO increased the stability as well as complexation efficiency of CDs. FTIR and DSC analysis indicated hydrogen bonding interaction POLO with QUN and CDs. XRD and SEM analysis revealed greater amorphization in case of multicomponent inclusion complexes. All complexes showed uniform drug content. QUN-HPβCD-POLO exhibited maximum solubility than the physical mixtures and other complexes. The pure QUN and QUN-HPβCD-POLO were tested for in vivo anti-inflammatory activity by Carrageenan induced rat paw edema method. QUN-HPβCD-POLO exhibited significant increase in anti-inflammatory activity as compared to pure QUN.