Characterization of Thymoquinone-Sulfobutylether-β-Cyclodextrin Inclusion Complex for Anticancer Applications

Febuxostat ternary inclusion complex using SBE7-βCD in presence of a water-soluble polymer: physicochemical characterization, in vitro dissolution, and in vivo evaluation

Febuxostat (FBX), a potent xanthine oxidase inhibitor, is widely used as a blood uric acid-reducing agent and has recently shown a promising repurposing outcome as an anti-cancer. FBX is known for its poor water solubility, which is the main cause of its weak oral bioavailability. In a previous study, we developed a binary system complex between FBX and sulfobutylether-β-cyclodextrin (SBE7-βCD) with improved dissolution behavior. The aim of the current study was to investigate the effect of incorporating a water-soluble polymer with a binary system forming a ternary one, on further enhancement of FBX solubility and dissolution rate. In vivo oral bioavailability was also studied using LC-MS/MS chromatography. The polymer screening study revealed a marked increment in the solubility of FBX with SBE7-βCD in the presence of 5% w/v polyethylene glycol (PEG 6000). In vitro release profile showed a significant increase in the dissolution rate of FBX from FBX ternary complex (FTC). Oral in vivo bioavailability of prepared FTC showed more than threefold enhancement in Cmax value (17.05 ± 2.6 µg/mL) compared to pure FBX Cmax value (5.013 ± 0.417 µg/mL) with 257% rise in bioavailability. In conclusion, the association of water-soluble polymers with FBX and SBE7-βCD system could significantly improve therapeutic applications of the drug.

Thymoquinone oxime synthesis and its effects on melanoma cells: cytotoxic, genotoxic, and apoptotic evaluation

Strong evidence supports the anticancer properties of natural plant product isolates. The cytotoxic, genotoxic, and apoptotic properties of an oxime derivative of thymoquinone (TQ) in melanoma cancer cells were investigated. The structure of TQ-Oxime was elucidated through nuclear magnetic resonance, and its effect on B16F10 and L929 cell lines was assessed using a luminometric adenosine triphosphate assay. Intracellular reactive oxygen species (iROS) were quantified via fluorometry, mitochondrial membrane potential (MMP) was assessed using flow cytometry, glutathione (GSH) levels were measured using a luminometric GSH/oxidized glutathione assay, DNA damage via comet assay, and apoptosis was detected using acridine orange/ethidium bromide staining. Concentrations (0.5-20 μM) of TQ-Oxime significantly increased cytotoxicity, DNA damage, apoptosis, and iROS, in a concentration-dependent manner compared (p < 0.001). In addition, MMP and GSH levels decreased significantly with increasing concentrations compared with the control (p < 0.001). Overall, these findings contribute to our understanding of the therapeutic potential of TQ and its derivatives in cancer treatment.

Inclusion Complexes of Ethanamizuril with β- and Hydroxypropyl-β-Cyclodextrin in Aqueous Solution and in Solid State: A Comparison Study

Ethanamizuril (EZL) is a new anticoccidial drug developed by our Shanghai Veterinary Research Institute. Since EZL is almost insoluble in water, we conducted a study to improve the solubility of EZL by forming inclusion complexes with β-cyclodextrin (β-CD) and hydroxypropyl-β-cyclodextrin (HP-β-CD). In this study, we performed molecular docking and then systematically compared the interactions of EZL with β-CD and HP-β-CD in both aqueous solution and the solid state, aiming to elucidate the solubilization effect and mechanism of cyclodextrins (CDs). The interactions were also examined in the solid state using DSC, PXRD, and FT-IR. The interactions of EZL with CDs in an aqueous solution were investigated using PSA, UV-vis spectroscopy, MS, 1H NMR, and 2D ROESY. The results of phase solubility experiments revealed that both β-CD and HP-β-CD formed inclusion complexes with EZL in a 1:1 molar ratio. Among them, HP-β-CD exhibited higher Kf (stability constant) and CE (complexation efficiency) values as well as a stronger solubilization effect. Furthermore, the two cyclodextrins were found to interact with EZL in a similar manner. The results of our FT-IR and 2D ROESY experiments are in agreement with the theoretical results derived from molecular simulations. These results indicated that intermolecular hydrogen bonds existing between the C=O group on the triazine ring of EZL and the O-H group of CDs, as well as the hydrophobic interactions between the hydrogen on the benzene ring of EZL and the hydrogen of CDs, played crucial roles in the formation of EZL/CD inclusion complexes. The results of this study can lay the foundation for the future development of high-concentration drinking water delivery formulations for EZL.

Enhancement of the solubility and oral bioavailability of altrenogest through complexation with hydroxypropyl-β-cyclodextrin

Altrenogest (ALT), a synthetic progestogen, serves a critical role in estrus synchronization among animals like gilts and mares. However, its practical application in animal husbandry is hampered due to its poor solubility and limited oral bioavailability. To address this challenge, a solvent evaporation method was employed to create an inclusion complex of ALT with hydroxypropyl-β-cyclodextrin (ALT/HP-β-CD). The formation of this inclusion complex was confirmed by scanning electron microscopy, power X-ray diffraction, differential scanning calorimetry, Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, and docking calculations. In addition, we further conducted pharmacokinetic investigation involving gilts, comparing ALT/HP-β-CD inclusion complex to an ALT oral solution. The physicochemical characterization results unveiled a transformation of ALT's crystal morphology into an amorphous state, with ALT effectively entering the cavity of HP-β-CD. Compared with ALT, the solubility of ALT/HP-β-CD inclusion complex increased by 1026.51-fold, and its dissolution rate demonstrated significant improvement. Pharmacokinetic assessments further revealed that the oral bioavailability of ALT/HP-β-CD inclusion complex surpassed that of the ALT oral solution, with a relative bioavailability of 114.08 %. In conclusion, complexation with HP-β-CD represents a highly effective approach to improve both the solubility and oral bioavailability of ALT.

Decreased Penetration Mechanism of Ranitidine Due to Application of Sodium Sulfobutyl Ether-β-Cyclodextrin

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.

Formulation of Silymarin-β Cyclodextrin-TPGS Inclusion Complex: Physicochemical Characterization, Molecular Docking, and Cell Viability Assessment against Breast Cancer Cell Lines

Silymarin (SIL) is a poorly water-soluble flavonoid reported for different pharmacological properties. Its therapeutic applications are limited due to poor water solubility. In this study, the solubility of silymarin has been enhanced by preparing freeze-dried binary and ternary complexes using beta cyclodextrin (βCD) and d-α-tocopherol polyethylene glycol 1000 succinate (TPGS). The stoichiometry of the drug and the carrier was selected from the phase solubility study. The dissolution study was performed to assess the effect of complexation on the release pattern of SIL. The formation of inclusion complexes was confirmed by different physicochemical studies. Finally, a cell viability assay (MCF 7; breast cancer cell line) was performed to compare the activity with free SIL. The phase solubilization results revealed the formation of a stable complex (binary) with a stability constant and complexation efficiency (CE) value of 288 mol L-1 and 0.045%. The ternary sample depicted a significantly enhanced stability constant and CE value (890 mol L-1 and 0.14%). The release study results showed a marked increase in the release pattern after addition of βCD (alone) in the binary mixture (49.4 ± 3.1%) as well as inclusion complex (66.2 ± 3.2%) compared to free SIL (32.7 ± 1.85%). Furthermore, with the addition of TPGS in SIL-βCD (ternary), the SIL release was found to be significantly enhanced from the SIL ternary mixture (79.2 ± 2.13%) in 120 min. However, fast SIL release was achieved with 99.2 ± 1.7% in 45 min for the SIL ternary complex. IR and NMR spectral analysis results revealed the formation of a stable complex with no drug-polymer interaction. The formation of complexes was also confirmed by the molecular docking study (docking scores of 4.1 and -6.4 kcal/mol). The in vitro cell viability result showed a concentration-dependent activity. The IC50 value of the SIL ternary complex was found to be significantly lower than that of free SIL. The findings of the study concluded that the prepared SIL inclusion complex can be used as an alternative oral delivery system to enhance solubility, dissolution, and biological activity against the tested cancer cell line.

Enhancing the Anti-Leukemic Potential of Thymoquinone/Sulfobutylether-β-cyclodextrin (SBE-β-CD) Inclusion Complexes

Leukemia, a condition characterized by the abnormal proliferation of blood cells, poses significant challenges in cancer treatment. Thymoquinone (TQ), a bioactive compound derived from black seed, has demonstrated anticancer properties, including telomerase inhibition and the induction of apoptosis. However, TQ's poor solubility and limited bioavailability hinder its clinical application. This study explored the use of Sulfobutylether-β-cyclodextrin (SBE-β-CD), a cyclodextrin derivative, to enhance the solubility and stability of TQ for leukemia treatment. SBE-β-CD offers low hemolytic activity and has been successfully employed in controlled drug release systems. The study investigated the formation of inclusion complexes between TQ and SBE-β-CD and evaluated their effects on leukemia cell growth and telomerase activity. The results indicated that the TQ/SBE-β-CD complex exhibited improved solubility and enhanced cytotoxic effects against K-562 leukemia cells compared to TQ alone, suggesting the potential of SBE-β-CD as a drug delivery system for TQ. The annexin V-FITC assay demonstrated increased apoptosis, while the qPCR quantification assay revealed reduced telomerase activity in leukemia cells treated with TQ/SBE-β-CD, supporting its anti-leukemic potential. The molecular docking analysis indicated a strong binding affinity between TQ and telomerase. However, further research is needed to optimize the apoptotic effects and minimize necrosis induction. In conclusion, TQ/SBE-β-CD shows promise as a novel strategy for leukemia treatment by inhibiting telomerase and enhancing the cytotoxic effects of TQ, offering a potential solution to overcome the limitations of TQ's poor solubility and bioavailability.