Formation of Rutin–β-Cyclodextrin Inclusion Complexes by Supercritical Antisolvent Precipitation

Abstract

In this work, rutin (RUT)–β-cyclodextrin (β-CD) inclusion complexes are prepared by Supercritical AntiSolvent (SAS) precipitation. Well-defined composite microparticles are obtained at guest:host ratios equal to 1:2 and 1:1 mol:mol. The dimensions of composite particles range between 1.45 ± 0.88 µm and 7.94 ± 2.12 µm. The formation of RUT–β-CD inclusion complexes has been proved by different analyses, including Fourier transform infrared spectroscopy, Differential Scanning Calorimetry, X-ray diffraction, and UV-vis spectroscopy. The dissolution tests reveal a significant improvement in the release rate of RUT from inclusion complexes. Indeed, compared to the unprocessed RUT, the dissolution rate is about 3.9 and 2.4 times faster in the case of the complexes RUT–β-CD 1:2 and 1:1 mol:mol, respectively. From a pharmaceutical/nutraceutical point of view, CD-based inclusion complexes allow the reduction of the polymer amount in the SAS composite formulations.

Determining the Optimal Conditions for the Production by Supercritical CO2 of Biodegradable PLGA Foams for the Controlled Release of Rutin as a Medical Treatment

“…It is a low molecular weight polyphenolic compound that has been extensively used in the treatment of different diseases because of its varied pharmacological properties, which includes antiallergic, anti-inflammatory, antibacterial, and antiviral activities [ 24 ]. Some authors have used supercritical antisolvent processes to precipitate or encapsulate rutin, either by itself or trapped inside another material [ 25 , 26 ]. However, supercritical solvent impregnation (SSI) has never been used for this purpose.…”

Production of carrier/antioxidant particles by Supercritical Assisted Atomization as an adjuvant treatment of the CoVID-19 pathology

“…The spectrum of unprocessed rutin is characterized by a shoulder at 3424 cm -1 due to the -OH group stretching [39] , an absorption peak at 1654-1600 cm -1 attributable to the carbonyl group C=O stretching, and a peak at a wave number equal to 1504 cm -1 associated with the aromatic C=C double bond; the bands at 1362-1294 cm -1 are attributable instead to the C–O group, while those at 1204-1043 cm -1 to the C–O–C groups [34] , [40] . The reduction in intensity (black vertical lines) or the disappearance (blue vertical line) of some characteristic bands of rutin in the spectrum of SAA powders indicate the probable complexation between CD and rutin, which seems to be at least partially incorporated in the cyclodextrin cavity [34] . It is reasonable to hypothesize a partial complexation in the case of rutin due to its molecular size which is greater than that of the other two flavonoids.…”

“…The characteristic bands of cyclodextrin dominate the spectra of SAA powders; in particular, some distinctive bands of luteolin (blue vertical lines) are visible in the spectrum of the physical mixture but they are absent in the spectrum related to SAA powders. The reduction in intensity or even the partial or total disappearance of bands which are typical of the active compound spectrum indicates the formation of an inclusion complex, as the guest molecule (luteolin) is incorporated into the cavity of the host molecule (CD) and, therefore, its characteristic bands are hidden [34] . The presence of a few characteristic bands of luteolin in SAA coprecipitated powders (green lines) suggests, in particular, the formation of partial complexes, i.e., a small part of the luteolin is located outside the cavity, recording some characteristic peaks.…”

“…Dissolution tests were performed using the identical UV/vis spectrophotometer in the following conditions: in the case of LUT and RUT, phosphate-buffered saline (PBS) at pH 7.4 was used as the liquid medium, which simulates colon environment, in agreement with the literature [18] , [34] , whereas, in the case of NAR, PBS at 6.8 was prepared, to simulate the intestinal condition [35] . Calibration curves were evaluated using diluted standards at five different concentrations of the active principle in PBS to convert the absorbance into concentration.…”

Preparation, Characterization and Molecular Dynamics Simulation of Rutin–Cyclodextrin Inclusion Complexes

“…Various methods can be used to prepare cyclodextrin inclusion complexes, such as the freeze-drying method, the saturated aqueous solution method, the co-precipitation method [ 17 ], the anti-solvent method [ 18 ] and the grinding method. For example, Liu et al prepared a dihydromyricetin/β-cyclodextrin inclusion complex using the freeze-drying method [ 19 ].…”