ABSTRACT
Methotrexate (MTX) injection has a short half-life and significant toxic side effects. In order to overcome the demerits of MTX injection, MTX@COF was prepared for subcutaneous injection by loading MTX in crosslinked cyclodextrin metal-organic framework (COF) in this study. The cationic lipid material (2, 3-dioleoyl-propyl)-trimethylamine (DOTAP) was then coated on the MTX@COF surface by solvent evaporation. Different surface charge characteristics were observed in the coated MTX@COF@DOTAP with no significant change in particle morphology. The in vitro release behaviors of sustained-release particles were investigated in water and phosphate buffer (pH 7.4), and the in vivo release characteristics were evaluated for pharmacokinetics in rats. The in vitro release results showed that the cumulative release of MTX, MTX@COF and MTX@COF@DOTAP within 6 h was 92.70%, 36.31% and 18.19% in water, respectively; the cumulative release of MTX, MTX@COF and MTX@COF@DOTAP within 4 h was 90.82%, 79.37% and 58.30% in phosphate buffer, respectively; the results showed that MTX@COF can significantly delay the release of MTX, the modification to MTX@COF by DOTAP can further delay the release of MTX. Pharmacokinetic studies in rats showed that the mean retention time [MRT(0-t)] and the time to peak (Tmax) of the subcutaneous injection of MTX@COF@DOTAP group were significantly prolonged compared with the MTX@COF group and the MTX group. The area under the concentration-time curve [AUC(0-t)] of the MTX@COF@DOTAP subcutaneous injection group was 1.8 times high as that of the MTX group. In this study, MTX@COF@DOTAP particles had a certain sustained-release effect, and could prolong the bioavailability of MTX by subcutaneous injection, which provided a new idea for the development of new MTX dosage forms.
ABSTRACT
Cyclodextrin metal-organic framework (CD-MOF) as a highly porous supramolecular carrier could be one of the solutions to the insolubility of isosteviol (STV). The solubility of STV was lower than 20.00 ng/mL at pH 1.0 and pH 4.5, whilst its solubility increased to 20,074.30 ng/mL at pH 6.8 and 129.58 ng/mL in water with a significant pH-dependence. The
ABSTRACT
Tremendous efforts have been devoted to the enhancement of drug solubility using nanotechnologies, but few of them are capable to produce drug particles with sizes less than a few nanometers. This challenge has been addressed here by using biocompatible versatile -cyclodextrin (-CD) metal-organic framework (CD-MOF) large molecular cages in which azilsartan (AZL) was successfully confined producing clusters in the nanometer range. This strategy allowed to improve the bioavailability of AZL in Sprague-Dawley rats by 9.7-fold after loading into CD-MOF. The apparent solubility of AZL/CD-MOF was enhanced by 340-fold when compared to the pure drug. Based on molecular modeling, a dual molecular mechanism of nanoclusterization and complexation of AZL inside the CD-MOF cages was proposed, which was confirmed by small angle X-ray scattering (SAXS) and synchrotron radiation-Fourier transform infrared spectroscopy (SR-FTIR) techniques. In a typical cage-like unit of CD-MOF, three molecules of AZL were included by the -CD pairs, whilst other three AZL molecules formed a nanocluster inside the 1.7 nm sized cavity surrounded by six -CDs. This research demonstrates a dual molecular mechanism of complexation and nanoclusterization in CD-MOF leading to significant improvement in the bioavailability of insoluble drugs.
ABSTRACT
OBJECTIVE:To prepare Ferulic acid/K/β-CD/metal organic framework (FA/K/β-CD/MOF) inclusion,and to opti-mize its preparation technology. METHODS:K/β-CD/MOF was synthesized by solvothermal method as inclusion material. Using FA as main component,FA/K/β-CD/MOF was prepared by grinding method. The preparation technology was optimized by orthogo-nal test using mole ratio of main component-inclusion material,grinding time,dropping time and inclusion temperature as factors, inclusion rate as index. Prepared FA/K/β-CD/MOF was indentified by IR spectrum and DSC,and inclusion rate and dissolution rate were determined. RESULTS:Optimized preparation technology was as follows as mole ratio of main main component to inclusion material 3∶1,dropping time 60 min,inclusion temperature 40 ℃,inclusion time 60 min. Prepared FA/K/β-CD-MOF had already formed a new kind of phase,and its average inclusion rate was(18.0±1.6)%(RSD=0.9%,n=6);its solubility was 15 times as much as FA(9.582 mg/ml vs. 0.647 mg/ml). CONCLUSIONS:FA/K/β-CD/MOF is prepared successfully;and the preparation tech-nology is reasonable and feasible.