Sodium Sulfobutylether-β-cyclodextrin (SBE-β-CD) is a derivative of β-cyclodextrin, characterized by its stereo structure, which closely resembles a truncated cone with a hydrophobic internal cavity. The solubility of insoluble substances within the hydrophobic cavity is significantly enhanced, reducing contact between the guest and the environment. Consequently, SBE-β-CD is frequently employed as a co-solvent and stabilizer. As the research progresses, it has been observed that the inclusion of SBE-β-CD is reversible and competitive. Besides, some inclusion complexes undergo distinct physicochemical property alterations compared to the guests. Additionally, certain guests exhibit varying inclusions with SBE-β-CD at different concentrations. These features have contributed to the expanding applications. SBE-β-CD finds widespread application in pharmaceutics as a protective agent and pK_a regulator, in pharmaceutical analysis as a chiral substance separator, and in biomedical engineering for encapsulating dyes and modifying sensors. The article will elaborate in detail on the physicochemical properties of SBE-β-CD, encapsulation principles, and factors influencing the formation of inclusion complexes. Furthermore, the review focuses on the application of SBE-β-CD through encapsulation in pharmaceutics, pharmaceutical analysis, and biomedical engineering. Finally, the prospects and potential applications of SBE-β-CD are discussed.

The diversity of cyclodextrins and their derivatives is increasing with continuous research. In addition to monomolecular cyclodextrins with different branched chains, cyclodextrin-based polymers have emerged. The aim of this review is to summarize these innovations, with a special focus on the study of applications of cyclodextrins and their derivatives in nano-delivery systems. The areas covered include nanospheres, nano-sponges, nanogels, cyclodextrin metal–organic frameworks, liposomes, and emulsions, providing a comprehensive and in-depth understanding of the design and development of nano-delivery systems.

Nasal drug delivery efficiency is highly dependent on the position in which the drug is deposited in the nasal cavity. However, no reliable method is currently available to assess its impact on delivery performance. In this study, a biomimetic nasal model based on three-dimensional (3D) reconstruction and three-dimensional printing (3DP) technology was developed for visualizing the deposition of drug powders in the nasal cavity. The results showed significant differences in cavity area and volume and powder distribution in the anterior part of the biomimetic nasal model of Chinese males and females. The nasal cavity model was modified with dimethicone and validated to be suitable for the deposition test. The experimental device produced the most satisfactory results with five spray times. Furthermore, particle sizes and spray angles were found to significantly affect the experimental device's performance and alter drug distribution, respectively. Additionally, mometasone furoate (MF) nasal spray (NS) distribution patterns were investigated in a goat nasal cavity model and three male goat noses, confirming the in vitro and in vivo correlation. In conclusion, the developed human nasal structure biomimetic device has the potential to be a valuable tool for assessing nasal drug delivery system deposition and distribution.

Permeability has an important effect on drug absorption. In this study, the effect of different concentrations of sodium sulfobutyl ether-β-cyclodextrin (SBE-β-CD) on the absorption of ranitidine was investigated to examine the mechanism of permeability changes. The results of a parallel artificial membrane permeability assay (PAMPA) showed that increasing the concentration of sodium sulfobutyl ether-β-cyclodextrin, 0, 0.12% (w/v), 0.36% (w/v) and 3.6% (w/v), respectively, caused the apparent permeability coefficient of ranitidine to decrease to 4.62 × 10⁻⁵, 4.5 × 10⁻⁵, 3.61 × 10⁻⁵ and 1.08 × 10⁻⁵ in Caco-2 cells, respectively. The same results were obtained from an oral pharmacokinetic study in rats. Further studies indicated that SBE-β-CD significantly increased the zeta potential of ranitidine. SBE-β-CD interacted with ranitidine charges to form a complex that reduced ranitidine permeability, and SBE-β-CD should be chosen with caution for drugs with poor permeability.

The encapsulation of sodium sulfobutylether-β-cyclodextrin (SBE-β-CD) is influenced not only by the degree of substitution (DS) but also by the presence of strong-bonded water (SBW). Guests compete with SBW for positions within the cavity of SBE-β-CD. However, the correlation between DS and SBW was not clear. This study revealed a positive correlation between DS and SBW utilizing Karl Fischer titration. The mechanism may be attributed to molecular polarizability. To explore the impact of SBW inside SBE-β-CD with different DS on encapsulation, density functional theory was employed. Throughout the release process, an increase in enthalpy is unfavorable, while an increase in entropy favors spontaneous reaction occurrence. For SBE-β-CD (DS = 2, 3), enthalpy increase is the primary factor, leading to the retention of SBW within the cavities and consequently hindering guest entry. In contrast, for SBE-β-CD (DS = 4, 7), the situation differs. For SBE₁₀-β-CD, the influence of SBW is minimal. This study aims to elucidate the relationship between DS and SBW, as well as the effect of SBW inside SBE-β-CD with different DS on encapsulation. It is crucial for a comprehensive understanding of the factors affecting the encapsulation of SBE-β-CD, thereby promoting quality control and functional development of SBE-β-CD.

Background: Baicalein (BA) is a poorly soluble flavonoid with limited oral bioavailability. This study aimed to enhance the solubility and nasal absorption of the compound using a dual-carrier system that combines cyclodextrin inclusion complexes and thermosensitive hydrogels. Methods: The inclusion complexes of BA with hydroxypropyl-β-cyclodextrin (HP-β-CD) or sulfobutyl-β-cyclodextrin (SBE-β-CD), namely BA-HP-β-CD and BA-SBE-β-CD, were prepared via solution stirring and characterized by solubility, dissolution, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis-differential scanning calorimetry (TG-DSC), and Madin-Darby canine kidney (MDCK) cell permeation. The optimal complexes were incorporated into chitosan/β-glycerophosphate thermosensitive hydrogels (BA/HP-Gel and BA/SBE-Gel), followed by evaluations of gelation properties, in vitro release, and in vivo pharmacokinetics in rats. Results: The water solubility of BA-HP-β-CD and BA-SBE-β-CD increased 572 and 582 times, with MDCK permeability enhanced by 5.3 and 2.9 times, respectively. Both hydrogels showed rapid solution-gel transition at nasal temperature and sustained release. Following intranasal administration, BA/HP-Gel and BA/SBE-Gel achieved relative bioavailabilities of 623.5% and 697.8%, respectively, compared with BA-Gel. Conclusions: The dual-carrier platform effectively improved BA solubility, permeability, and nasal bioavailability, offering a promising strategy for nasal delivery of poorly soluble drugs.