Preparation and Characterization of a Hybrid Complex of Cyclodextrin-Based Metal—Organic Frameworks-1 and Ascorbic Acid Derivatives

Abstract

Cyclodextrin-based metal–organic frameworks-1 (CD-MOF-1) prepared using potassium hydroxide, ethanol, and γ-cyclodextrin (γ-CD) has been reported as a new type of MOF for the development of pharmaceutical formulations. The present study aimed to investigate the physicochemical properties of ascorbic acid derivatives (L-ascorbyl 6-palmitate (ASCP); L-ascorbyl 2,6-palmitate (ASCDP)) complexed with CD-MOF-1 by a solvent evaporation method. Powder X-ray diffraction revealed that the crystal diffraction pattern of CD-MOF-1 changed from α-type to β-type when prepared by a solvent evaporation method. For ASCP/CD-MOF-1 = 1/2 and ASCDP/CD-MOF-1 = 1/4 evaporated samples, the crystal diffraction peaks derived from ASCP and ASCDP disappeared, indicating a β-like behavior. Differential scanning calorimetry results revealed that the endothermic peaks of evaporated samples (ASCP/CD-MOF-1 = 1/2 and ASCDP/CD-MOF-1 = 1/4) were not detected due to melting. Furthermore, intermolecular interactions were observed in the hydrogen bonds between the CH groups of the side chains of ASCP and ASCDP and the OH group of CD-MOF-1 in (ASCP/CD-MOF-1 = 1/2) and EVP (ASCDP/CD-MOF-1 = 1/4), based on the near-infrared absorption spectroscopy analysis. CD-MOF-1 did not form inclusion complexes with the lactone rings of ASCP and ASCDP, but with the lipophilic side chains. These results suggested that CD-MOF-1 may be useful in preparing novel drug carriers for ASCP and ASCDP.

Regularities of Encapsulation of Tolfenamic Acid and Some Other Non-Steroidal Anti-Inflammatory Drugs in Metal-Organic Framework Based on γ-Cyclodextrin

“…Metal-organic frameworks based on cyclodextrins (CD-MOF) are biocompatible crystalline structures with a highly developed specific surface area. Due to the presence of pores of different diameter, CD-MOFs are able to accommodate various substances, acting not only as carriers, but also as an effective solubilizers [ 11 , 12 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ]. For example, it has been demonstrated that γ-CD-based MOFs (γCD-MOF) can serve as superior carriers for curcumin [ 17 , 18 ], ascorbic acid derivatives [ 19 ], hexanal [ 20 ], methotrexate [ 21 ], and leflunomide [ 22 ].…”

Synergistic applications of cyclodextrin-based systems and metal–organic frameworks in transdermal drug delivery for skin cancer therapy

“…The articles catalogued in Table 3 primarily center on MOF-based transdermal systems as a potential remedy for melanoma and an array of wounds such as diabetic, chronic, and infected wounds. CD-MOFs have shown to be able to encapsulate various drugs and active compounds, including doxorubicin, 176,177 resveratrol, 140,178 epigallocatechin gallate, 179 vitamin A palmitate, 180 ascorbic acid derivatives, 181 myricetin, 182 ketoconazole, 183 salicylic acid, 140 ferulic acid, 140,163 different NSAIDs, 184 emodin and quercetin. 128…”

CD-MOF-1 Growth on Polysaccharide Gels through Only C2–OH/C3–OH or C5–O/C6–OH Group Formed Four-Coordinated K+ Ions for Developing Porous Biogels

“…The 1 H CPMAS NMR and 13 C CPMAS NMR were employed to further investigate the host−guest interaction sites between eugenol and CD-MOF-1 by using an AVANCE NEO 600 MHz SS NMR instrument (Bruker AXS GmbH, Karlsruhe, Germany).…”

“…The primary change of γ-CD unit cavity before and after introducing eugenol is due to potential host−guest attractions. The 1 H liquid-state (LS) NMR and 13 C solid-state (SS) NMR spectra were employed to further investigate intermolecular interactions of eugenol and CD-MOF-1. Based on the 1 H LS NMR result, each γ-CD unit carried 0.87 eugenol calculated by the integration ratio of the peak at 5.03 ppm (−C1−H, doublet) from the γ-CD unit of CD-MOF-1 and the chemical shift at 5.94 ppm (�CH−, multiplet) from eugenol (Figure S22).…”

“…However, the encapsulated eugenol molecules in pores are not easy to escape because the short side of eugenol (0.92 × 0.70 nm) is very similar to the window pore of CD-MOF-1 (0.78 nm). Furthermore, 13 C CPMAS nuclear magnetic resonance ( 13 C CP/MAS NMR) suggested that carbon chemical shifts of C2, C3, and C5 were distinctly shifted to high field with Δδ of −1.37 ppm and low field with Δδ of 0.23 ppm (Figure S24 and Table S4), which suggested that eugenol in CD-MOF-1 was closer to C2, C3, and C5 of pyranoid rings. Moreover, 13 C resonances corresponding to C6 from the γ-CD unit of CD-MOF-1 dramatically shifted to low fields with Δδ of 0.16 ppm.…”