Characterization of silk fibroin based films loaded with rutin–β-cyclodextrin inclusion complexes

Abstract

In this study, cyclodextrin inclusion complexes with rutin were prepared via co-precipitation method. Stability constant and solubility energy of beta-cyclodextrin complex were calculated as 262 M -1 and 1,737 kJ mol -1 , respectively. Aqueous solubility of rutin was increased with inclusion complex of beta-cyclodextrin. The effect of temperature on both aqueous solubility of free rutin, and its inclusion complex was also studied. Characterization of cyclodextrin complexes were conducted with UV-Vis spectrophotometry, Fourier transform infrared spectroscopy, X-ray diffractometry, differential scanning calorimetry, thermal gravimetric analysis, nuclear magnetic resonance spectroscopy and scanning electron microscopy techniques. Characterization results supported formation of inclusion complexes. Dissolution profiles of rutin, physical mixture and inclusion complex of rutin were observed at 37°C. Dissolution results proved the effect of cyclodextrin addition on solubility rate of rutin. After loading rutin and its complexes into silk fibroin based films, release tests were performed at 37°C in neutral pH conditions for 24 h. Most of the rutin were released from silk fibroin films within the first 5 h and the rest of it was released slowly (sustained release). Electron microscope analyses showed that films had homogenous and dense morphologies. These results revealed that silk fibroin is useful for preparing bioactive films loaded with natural compounds and for modifying their release behaviour at physiological conditions.

Physico-Chemical and Pharmaco-Technical Characterization of Inclusion Complexes Formed by Rutoside with β-Cyclodextrin and Hydroxypropyl-β-Cyclodextrin Used to Develop Solid Dosage Forms

“…The SEM images show only both crystalline structures of the individual components. The same morphologies were found in the literature for similar compounds [36,38,39]. Analyzing the SEM images for RUT-β-CD (Figure 2A) and RUT-HP-β-CD (Figure 2B) inclusion complexes, it can be noticed the presence of some homogeneous slightly amorphous powders with fine and regular crystals.…”

Effects of addition of condensed tannin on the structure and properties of silk fibroin film

“…(data summarized in Table ), the pure SF film displays two endothermic phase transition at about 110 °C ( T w ) and 155 °C ( T g ) as well as an exothermic phase transition at 218 °C ( T c ). They are related to water evaporation from the sample during the DSC heating, to the glass transition of SF chains and to the conformational transition from random coil to β ‐sheet during the heating . The tannin addition does not result in significant change of T w of blend films.…”

“…On the other hand, there has been an increase of importance for SF films possessing bioactivities in order to meet specific requirements in use. Varieties of bioactive SF films for use in the biomedical field have been fabricated by incorporating SF with natural bioactive compounds, such as heparin, biotin, curcumin and modified rutin . In other research, SF films have been endowed with antimicrobial properties by addition of grape seed polyphenols for use in edible packing to prolong the shelf time of muscle foods…”

Silk fibroin‐based films in food packaging applications: A review

“…Evaporating water vapor and transforming SF from random coil to β‐sheet networks produce endothermic peaks in the regenerated SF from 40 to 140°C. These peaks could be detected by the DSC curve (Fan et al., 2013; Peña et al., 2010; Şamlı et al., 2014). DSC is the most popular method for determining the glass transition temperature.…”

“…Meanwhile, DSC is a thermal analysis tool that measures the heat flow of the sample over time and its temperaturerelated alterations (Bierhalz et al, 2020;Haynie, 2001;Usmani et al, 2017). Evaporating water vapor and transforming SF from random coil to β-sheet networks produce endothermic peaks in the regenerated SF from 40 to 140 • C. These peaks could be detected by the DSC curve (Fan et al, 2013;Peña et al, 2010;Şamlı et al, 2014). DSC is the most popular method for determining the glass transition temperature.…”