Antipyrine–gamma cyclodextrin inclusion complex: Molecular modeling, preparation, characterization and cytotoxicity studies

Intestinal-Targeted Digestion of Heme Chloride by Forming Inclusion Complexes In Vitro

Hemin, a heme-like compound with significant biological activity, shows promise as an iron supplement for humans. Nonetheless, its poor solubility in water greatly impedes its absorption and utilization. To surmount this obstacle, researchers have chosen various cyclodextrins with distinct cavity sizes and derivative groups to act as hosts, forming inclusion complexes with hemin chloride. Among these, γ-cyclodextrin has been identified as the optimal carrier, based on a thorough evaluation of its encapsulation efficiency, solubility, and molecular docking. Multiple characterization techniques further confirmed the formation of these inclusion complexes. Results from IEC-6 cell experiments indicated that the cytotoxicity of the inclusion complexes was lower than that of FeSO4. Static and dynamic gastrointestinal simulation digestion systems were established, and the results showed that the bioavailability of the inclusion complex was significantly higher than that of raw hemin. Additionally, only about 0.29% of hemin chloride is digested by gastric enzymes, whereas 9.52% is digested by pancreatic enzymes in the static gastrointestinal simulation digestion system, with similar outcomes observed in the dynamic system. These findings suggest that targeted digestion in the intestine significantly enhances the bioavailability of hemin chloride by forming inclusion complexes in vitro.

Drug-Facilitated Crystallization of Spray-Dried CD-MOFs with Tunable Morphology, Porosity, And Dissolution Profile

Metal-organic frameworks (MOFs) with versatile functionalities have applications in environmental science, sensor separation, catalysis, and drug delivery. In particular, MOFs used in drug delivery should be biodegradable and easy to control. In this study, spray-dried cyclodextrin-based MOFs (CD-MOFs) with tunable crystallinity, porosity, and dissolution properties were fabricated. The spray-drying precursor properties, such as ethanol volume ratio, incubation time, and precursor concentration, were optimized for controlled crystallization. On the basis of the morphology, X-ray diffraction peak intensity, and specific surface areas of the spray-dried CD-MOF products, they were categorized as amorphous, partially crystalline, and highly crystalline. An active pharmaceutical ingredient ketoconazole (KCZ) was introduced into the precursor to prepare KCZ-containing CD-MOFs. The surface areas of these products were greater by 3-fold (292 m2/g) than that of the plain CD-MOF (94.1 m2/g) prepared using the same parameters. The presence of KCZ in the hydrophobic cavity between the two γ-CD molecules was correlated to the CD-MOF crystal growth. Additionally, CD-MOF particles exhibited different dissolution behaviors on the basis of the position of KCZ in the MOF. These spray-dried CD-MOFs with tunable morphology, specific surface area, and dissolution could have potential applications in various fields.

Application of Molecular Dynamics Simulations in the Analysis of Cyclodextrin Complexes

Cyclodextrins (CDs) are highly respected for their ability to form inclusion complexes via host-guest noncovalent interactions and, thus, ensofance other molecular properties. Various molecular modeling methods have found their applications in the analysis of those complexes. However, as showed in this review, molecular dynamics (MD) simulations could provide the information unobtainable by any other means. It is therefore not surprising that published works on MD simulations used in this field have rapidly increased since the early 2010s. This review provides an overview of the successful applications of MD simulations in the studies on CD complexes. Information that is crucial for MD simulations, such as application of force fields, the length of the simulation, or solvent treatment method, are thoroughly discussed. Therefore, this work can serve as a guide to properly set up such calculations and analyze their results.

Spray dried nanospheres for inclusion complexes of cefpodoxime proxetil with β-cyclodextrin, 2-hydroxypropyl-β-cyclodextrin and methyl-β-cyclodextrin: improved dissolution and enhanced antibacterial activity

OBJECTIVE

The aim of the current research was the development hard cellulose capsules containing cefpodoxime proxetil (CEF) (BCS-Class II) encapsulated nanospheres of inclusion complexes with β-CD, HP-β-CD and M-β-CD for efficient antibacterial therapy.

SIGNIFICANCE

The reason for this phenomenon is to bring an innovative approach to effective oral antimicrobial therapy with hard cellulose capsules containing spray dried nanospheres of CEF with β-CD, HP-β-CD and M-β-CD by means of increased solubility, dissolution rate and improved antibacterial efficiency with lower oral dose.

METHODS

Phase solubility analyses was performed to evaluate the drug/CD interaction, involving the stoichiometry and apparent stability constant. Following the preparation of inclusion complexes by spray-drying method, complexes were characterized for physical, solid-state and microbiological analyses. In vitro dissolution from hard cellulose capsules containing CEF and CEF/β-CD, CEF/HP-β-CD and CEF/M-β-CD complexes were performed.

RESULTS

According to AL type phase solubility curves, complexes were formulated as 1:1 molar ratio. The solubility of pure CEF was determined as 0.241 ± 0.002 mg mL-1, the solubility of inclusion complexes increased solubility from 3 to 5 times. The strong host-guest interaction was confirmed for CEF/HP-β-CD and CEF/M-β-CD complexes with SEM, DSC, FT-IR and 1H-NMR analyses. Inclusion complexes were more efficient on bacterial cells (2-4 fold) than pure CEF both Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae. Hard-cellulose capsules filled with inclusion complexes exhibited significantly faster release than unprocessed CEF.

CONCLUSION

Hard-cellulose capsules containing CEF/HP-β-CD and CEF/M-β-CD complexes appear to be superior alternative to commercially available CEF tablets for effective antibacterial therapy.

Physicochemical investigations on non-covalent interactions between Padimate O and cyclodextrin receptors in both solution and solid states

Ultraviolet B (UV-B) radiation is very harmful to human body. It can cause serious health problem mainly skin cancer, sunburn and photo-aging. Padimate O (PMO) is a sunscreen agent. The aim of this work is to form inclusion complexes with α-cyd and β-cyd in both aqueous environment and solid state that established by UV-Vis, FTIR spectroscopy, mass spectra, powder X-ray diffraction pattern and as α-cyd and β-cyd are known to us as good drug vehicles, hence, the experimental results suggest that they can be used as good sunscreen agent carrier and photostabilizer additive for increasing the photostability and other properties of PMO. In solution phase, UV-Vis spectroscopy demonstrated that the entire process of formation of complexes is observed with 1:1 stoichiometry which is further justified by mass spectra. Thermodynamic parameters support the whole process in both cases and it is revealed that β-cyd forms more firmly inclusion complex than α-cyd with PMO. Successful formation of solid inclusion complexes is supported by FTIR spectroscopy and powder-XRD. The enhancement of the thermal stability of the α-cyd/PMO and β-cyd/PMO complexes is demonstrated by TGA study.

Cyclodextrin-based telmisartan ophthalmic suspension: Formulation development for water-insoluble drugs

In this study, cyclodextrin-based aqueous eye drop suspension of the water insoluble drug telmisartan was developed. Formation of a drug/γ-cyclodextrin complex was enabled by preventing formation of a poorly water-soluble zwitterion using a volatile base that was removed upon drying of the complex powder. Hydroxypropyl methylcellulose was shown to have the overall best effect, stabilizing the complexes without hampering the drug release from the formulation. Two strategies for preparing cyclodextrin-based aqueous eye drop suspensions of telmisartan were investigated, one where hydroxypropyl methylcellulose was added to the medium during preparation of the drug/γ-cyclodextrin complex powder (ternary complex) and the other where hydroxypropyl methylcellulose was added to the complex powder after preparation of the complex (binary complex). The complexation was characterized by DSC, FT-IR and (1)H NMR and the eye drop suspensions formed were examined regarding their stability and in vitro mucoadhesion property. The ternary complex exhibited inferior mucoadhesive property compared to the binary complex. However, the ternary complex was more stable as no notable change in particle size and particle size distribution was observed during storage at 4°C over 6 months (p<0.05) with the mean particle size determined between 2.0 and 2.5μm.