Physicochemical characterization and in vitro dissolution performance of ibuprofen-Captisol® (sulfobutylether sodium salt of β-CD) inclusion complexes

Abstract

The aim of the present research work was to explore the impact of ibuprofen-captisol® (sulfobutylether sodium salt of β-CD) inclusion complexes on in vitro dissolution performance. Phase solubility studies of ibuprofen using the carrier captisol® had generated AL-type profiles which indicated the formation of 1:1 stoichiometric inclusion complexes. The study revealed that more stable complexes of ibuprofen-captisol® were formed in double distilled water compared to phosphate buffer (pH7.2) as more fraction of the drug is in un-ionized form. Ibuprofen-captisol® complexes were prepared by (i) kneading and (ii) freeze-drying technique with the various drug-carrier ratio (1:1, 1:3 and 1:5w/w). Complex formation was explained on the basis of physical mixtures (PMs) of identical compositions. Fourier transform infrared spectroscopy (FT-IR), Differential scanning calorimetry (DSC), X-ray powder diffractometry (XRPD), Scanning electron microscope (SEM) and Molecular docking studies were carried out to establish the inclusion complexation. Molecular docking confirmed the possibility of forming a complex between drug and polymer, and it was evident from the energy-minimized structure of the drug-polymer complex. Minimization of energy suggested the formation of a stable drug-polymer complex with binding energy of (−) 3.6kcalmol−1. The negative docking energy of the complex formation justifies the reason of its solubility enhancement. The complexes prepared by freeze-drying technique were found to be superior in the enhancement of in vitro dissolution rate of ibuprofen when compared to that of complexes prepared by kneading technique.