Drug-Drug Cocrystal Alloy and Nanoformulation of Cytarabine: Optimized Biopharmaceutical Property and Synergistic Antitumor Efficacy.

An integrated strategy by combining cocrystallization with nanotechnology is developed to optimize in vitro/vivo performances of marine antitumor drug cytarabine (ARA) and further obtain innovative insights into the exploitation of cocrystal alloy nanoformulation. Therein, the optimization of properties and synergistic effects of ARA mainly depends on assembling with uracil (U) and antitumor drug 5-fluorouracil (FU) into the same crystal by cocrystallization technology, while the long-term efficacy is primarily maintained by playing the superiority of nanotechnology. Along this line, the first cocrystal alloy of ARA, viz., ARA-FU-U (0.6:0.4), is successfully obtained and then transformed into a nanocrystal. Single-crystal X-ray diffraction analysis demonstrates that this cocrystal alloy consists of two isomorphic cocrystals of ARA, namely, ARA-FU and ARA-U, in 0.6:0.4 ratio. An R22(8) hydrogen-bonding cyclic system formed by a cytosine fragment of ARA with U or FU can protect and stabilize the amine group on ARA, laying the foundation for regulating its properties. The in vitro/in vivo properties of the cocrystal alloy and its nanocrystals are investigated by theoretical and experimental means. It reveals that both the alloy and nanocrystal can improve physicochemical properties and promote drug absorption, thus bringing to optimized pharmacokinetic behaviors. The nanocrystal produces superior effects than the alloy that helps to extend therapeutic time and action. Particularly, relative to the corresponding binary cocrystal, the synergistic antitumor activity of ARA and FU in the cocrystal alloy is heightened obviously. It may be that U contributes to reducing the degradation of FU, specifically increasing its concentration in tumors to enhance the synergistic effects of FU and ARA. These findings provide new thoughts for the application of cocrystal alloys in the marine drug field and break fresh ground for cocrystal alloy formulations to optimize drug properties.

Cocrystallization-Driven Double-Optimized Stratagem toward Directional Self-Assembly for the First Ternary Salt Cocrystal of Cardiotonic Drug Milrinone with Different Phenolic Acids Exhibits Optimal In Vitro/Vivo Biopharmaceutical Peculiarities.

The current research leverages the structural features and property superiorities along with benefits in protecting cardiovascular system of gallic acid (GLC) and gentisic acid (HGA) to optimize in vitro/vivo peculiarities of cardiotonic drug milrinone (MIL) through developing a stratagem of cocrystallization-driven double-optimized ternary salt cocrystal. This strategy assembles MIL ternary salt cocrystal by shaping a cocrystallization moiety relying on noncovalent interplays with GLC to obtain permeability advancement and molding a salt segment via the salification of proton transfer between HGA and MIL molecules to facilitate solubility enhancement. While the ameliorative in vitro properties further modulate the in vivo pharmacokinetic behaviors, thus fulfilling a dual optimization of MIL's biopharmaceutical characteristics on both in vitro and in vivo aspects. Along this line, the first MIL ternary salt cocrystal, viz., [HMIL+-GA-]-MIL-GLC-H2O (denoted as MTSC hereinafter), has been satisfactorily constructed and precisely structurally identified by diversified techniques. The single-crystal X-ray diffraction experiment validates that a molecular salt [HMIL+-GA-] species cocrystallizes with one neutral MIL, two GLC, and five solvent water molecules, among which the organic constituents compose laminated hydrogen bond networks, and then are self-assembled by water molecules to a 3D supramolecular structure. The unique structural feature and stacking pattern of MTSC make both the permeability and solubility be respectively enhanced by 9.69 times and 5.17- to 6.03-fold compared with the parent drug per se. The experimental outcomes are powerfully supported by associated calculations based on density functional theory. Intriguingly, these optimal in vitro physicochemical natures of MTSC have been potently converted into strengths of in vivo pharmacokinetics, showcasing the elevated drug plasma concentration, elongated half-life, alongside advanced bioavailability. Consequently, this presentation not just contributes a brand-new crystalline form with utility values, but ushers in a new dimension of ternary salt cocrystals for improving in vitro/vivo limitations of poor drug bioavailability.

Bifonazole caffeate: The first molecular salt of bifonazole with enhanced biopharmaceutical property based on experiments and quantum chemistry research.

In order to make novel breakthroughs in molecular salt studies of BCS class-IV antifungal medication bifonazole (BIF), a salification-driven strategy towards ameliorating attributes and aiding augment efficiency is raised. This strategy fully harnesses structural characters together attributes and benefits of caffeic acid (CAF) to concurrently enhance dissolvability and permeability of BIF by introducing the two ingredients into the identical molecular salt lattice through the salification reaction, which, coupled with the aroused potential activity of CAF significantly amplifies the antifungal efficacy of BIF. Guided by this route, the first BIF-organic molecular salt, BIF-CAF, is directionally designed and synthesized with satisfactorily structural characterizations and integrated theoretical and experimental explorations on the pharmaceutical properties. Single-crystal X-ray diffraction resolving confirms that there is a lipid-water amphiphilic sandwich structure constructed by robust charge-assistant hydrogen bonds in the salt crystal, endowing the molecular salt with the potential to enhance both dissolvability and permeability relative to the parent drug, which is validated by experimental evaluations. Remarkably, the comprehensive DFT-based theoretical investigations covering frontier molecular orbital, molecular electrostatic potential, Hirshfeld surface analysis, reduced density gradient, topology, sphericity and planarity analysis strongly support these observations, thereby allowing some positive relationships between macroscopic properties and microstructures of the molecular salt can be made. Intriguingly, the optimal properties, together with the stimulated activity of CAF markedly augment in vitro antifungal ability of the molecular salt, with magnifying inhibition zones and reducing minimum inhibitory concentrations. These findings fill in the gaps on researches of BIF-organic molecular salt, and adequately exemplify the feasibility and validity by integrating theoretical and experimental approaches to resolve BIF's problems via the salification-driven tactic.

The first nano-cocrystal formulation of marine drug cytarabine with uracil based on cocrystal nanonization strategy for long-acting injection exhibiting enhanced antitumor activity.

To emphasize the superiority of uracil (UR) in ameliorating biopharmaceutical characteristics of marine antitumor medicine cytarabine (ARA), thus gaining some innovative opinions for the exploitation of nanococrystal formulation, a cocrystal nanonization strategy is proposed by integrating cocrystallization and nanosize preparation techniques. For one thing, based on UR's unique structural features and natures together with advantages of preferential uptake by tumor cells, cocrystallizing ARA with UR is expected to improve the in vitro/vivo performances. For another, the nanonization procedure is oriented towards maintaining the long-term effective drug level. Along this route, a cocrystal of ARA with UR, viz., ARA-UR, is successfully synthesized and then transformed into nano-cocrystal. The cocrystal structure is precisely confirmed by various methods, demonstrating that a 1:1 ARA and UR in the crystal forms cytosine-UR hydrogen-bonding interactions, thus constructing supramolecular frameworks by strong π-π stacking interplays; while the nano-cocrystal is block-shaped particles of 562.70 nm with zeta potential -33.40 mV. The properties of cocrystal ARA-UR and its nano-cocrystal in vitro/vivo are comparatively explored by theoretical calculations and experimental analyses, revealing that permeability of both is significantly increased than ARA per se. Notably, the meliorative natures of both the cocrystal and nano-cocrystal in vitro bring excellent antitumor activity, but the latter has greater strengths over the former. More notably, the nano-cocrystal can sustain effective concentration for a relatively longer time, causing lengthened retention time and better absorption in vivo. The contribution offers a fire-new dosage form of ARA for long-lasting delivery, thus filling the vacancy in nanococrystal studies about marine drugs.

The first marine dual-drug cocrystal of cytarabine with 5-fluorouracil having synergistic antitumor effects shows superior biopharmaceutical peculiarities by oral administration.

In order to highlight the advantages of cocrystallization technique in perfecting in vitro/vivo natures of marine drug cytarabine (ARC), and fill the gap of the research of marine pharmaceutical cocrystals with synergistic antitumor effects, the first dual-drug cocrystal simultaneously containing ARC and antitumor drug 5-fluorouracil (FU), viz. ARC-FU, is successfully designed and assembled. The accurate structure is perfectly resolved by single-crystal X-ray diffraction and other approaches. The analytical outcomes demonstrate that the codrug cocrystal consists of ARC and FU with a molar ratio of 1:1, in which FU molecule plays an important role by participating in the formation of both "pyrimidine-pyrimidine" and "pyrimidine-sugar" cyclic hydrogen-bonding systems with ARC molecules. In the cocrystal, there are twofold hydrogen-bonding helixes of ARC molecules and a whole three-dimensional hydrogen-bonding network which also contains the aromatic stacking interaction between pyrimidine rings of both components. Such structural feature and aggregation model have crucial influences on the improvements of in vitro/vivo properties, which is methodically verified by the combination of theoretical analyses and experimental measurements. The in vitro studies exhibit the suitably reduced solubility and obviously increased permeability for the cocrystal that is in accord with the theoretical prediction. Importantly, the ameliorated in vitro peculiarities realize in vivo pharmacokinetic optimization including the extended residence time and enhanced relative bioavailability. Of greater significance, ARC exerts synergistic antitumor effects in association with FU that brings about potentiation of cell growth inhibition with lower IC50. Thus, this research not only provides a novel crystalline form for ARC with forward-looking development value, but also breaks new ground for the development of synergistic antitumor pharmaceutical cocrystals with marine characteristics.

5-fluorouracil-caffeic acid cocrystal delivery agent with long-term and synergistic high-performance antitumor effects.

Aim: To explore how to transform cocrystals of the anticancer drug 5-fluorouracil (FL) with caffeic acid (CF; FL-CF-2H2O) into a nanoformulation, a self-assembly strategy of cocrystal-loaded micelles is proposed. Methods: Nanomicelles were assembled to deliver cocrystal FL-CF-2H2O with synergistic activity, and their in vitro/vivo properties were evaluated by combining theoretical and experimental methods. Result: More cocrystal was packed into the polymers due to the stronger interaction energy during micellar assembly, producing excellent cytotoxicity and pharmacokinetic behavior, especially synergistic abilities and long-term therapy. Conclusion: This case exemplifies the particular benefits of the self-assembly strategy of cocrystal-loaded micelles in keeping a delicate balance between long-term effects and high efficiency for FL, and offers a feasible technical scheme for cocrystal delivery agents for antitumor drugs.

To exemplify the feasibility of the cocrystal conversion of anticancer drug 5-fluorouracil (FL) with phenolic acid nutrient caffeic acid (CF) into a nanomicelle formulation, and further provide new options for the development of slowed-release cocrystal formulations with long-acting and synergistic antitumor effects, in this study, a cocrystalline complex of FL and CF (cocrystal FL-CF-2H₂O) was loaded into polymer PEG-PCL to successfully assemble the cocrystal nanomicelles by a self-assembly strategy. The morphology of the cocrystal nanomicelles was characterized, and in vitro/vivo properties were evaluated by combining theoretical with experimental methods. The results showed that the cocrystal nanomicelles with regular sphericity and homogeneous particle size had greater drug loading and entrapment efficiency than FL nanomicelles, which is also supported by theoretical predictions of the interaction energy between the cocrystal FL-CF-2H₂O and polymer PEG-PCL. The excellent encapsulation effects give rise to more potent cytotoxicity, better absorption and prolonged retention time in vivo. Relative to FL nanomicelles, the present cocrystal nanomicelles with synergistic antitumor abilities exhibited prominent slowed-release behavior that was more conducive to the long-term maintenance of therapeutic concentrations in vivo. The present case offers a feasible technical scheme for successful nanoformulation research on synergistic antitumor pharmaceutical cocrystals.

A novice cocrystal nanomicelle formulation of 5-fluorouracil with proline: The design, self-assembly and in vitro/vivo biopharmaceutical characteristics.

To fully play the advantages of cocrystallization and nano-preparation techniques in regulating in vitro/vivo biopharmaceutical properties of anticancer drug 5-fluorouracil (FU), and further exploit new avenues in its formulation development, a recombination strategy of cocrystallization and nano-micellar self-assembly techniques is proposed. Thereinto, the cocrystallization technique is aiming at augmenting antitumor ability by ameliorating physicochemical performances of FU, while the nano-micellar self-assembly technique is mainly employed to achieve slowed release and long-term efficacy. Guided by this strategy, a new zwitterionic cocrystal of FU with L-proline (PL), FU-PL, is successfully synthesized, and then incorporated into carriers PEG-PCL to gain cocrystal micelles. The structure of FU-PL cocrystal and morphology of the cocrystal micelles are respectively characterized via various analytical means. The comparative studies of in vivo/vitro properties are systematacially conducted by theoretical and experimental methods. The results showcase that the cocrystal's solubility and permeability are 4.60 and 3.89 folds higher than those of pristine drug FU at pH 6.8, separately; and the drug loading and entrapment efficiency of the obtained cocrystal micelles with spherical particles of 146 nm are 2.39 and 1.74 times than those of FU micelles itself, respectively. Particularly, both the cocrystal and its micelles eventually bring about the excellent antitumor activity, but the cocrystal micelles improve even more significantly in comparison with the cocrystal. These in vitro advantages have promoted the in vivo absorption with increased relative bioavailability (FREL) of 2.72 relative to FU-PL cocrystal. More particularly, the cocrystal micelles have preferable sustained-release action relative to FU micelles, thus more efficaciously prolonging the half-life and therapy duration. All these findings not only supply a novice slow-release dosage form for FU with greater efficiency, but also fill the blank of the micelle researches for antitumor pharmaceutical cocrystals.

A novel crystalline molecular salt of sulfamethoxazole and amantadine hybridizing antiviral-antibacterial dual drugs with optimal in vitro/vivo pharmaceutical properties.

In order to exploit the advantages to the full of multidrug salification strategy in amending the pharmaceutical properties of drugs both in vitro and in vivo, and further to open up a new way for its applications in bacteria-virus mixed cross-infection drugs, a novel dual-drug crystalline molecular salt hybridizing antibacterial drug sulfamethoxazole (SFM) with antiviral ingredient amantadine (ATE), namely SFM-ATE, is successfully designed and synthesized via multidrug salification strategy oriented by proton exchange reaction. The crystal structure of the firstly obtained molecular salt is precisely identified by employing single-crystal X-ray diffraction and multiple other techniques. The results show that, in the crystal lattice of molecular salt SFM-ATE, the classical hydrogen bonds together with charge-assisted hydrogen bonds contribute to two- dimensional networks, between which the hydrophobic interaction plays an important role. The relevant in vitro/vivo pharmaceutical properties of the dual-drug molecular salt are carried out through a comparative investigation of theoretical and experimental methods. It has been found that SFM displays concurrent improvements over the bulk drug in its permeability and dissolution after forming the molecular salt, which is supported by the molecular electrostatic potential calculation and Hirshfeld surface analysis. Encouragingly, the perfected in vitro biopharmaceutical properties can effectually turn into the in vivo pharmacokinetic preponderances with the expedited peak plasma concentration, lengthened half-life and enhanced bioavailability. Better yet, the antibacterial activities of SFM from the molecular salt get stronger with enlargement in inhibition areas and reduction in values of minimum inhibitory concentrations against the tested bacterial strains. Consequently, the present contribution not only supplies an opportunity for widening applications for classical sulfa drugs via dual-drug salification strategy, but also offers an alternative approach in dealing with viral-bacterial coinfection even other complex diseases by drugs' hybridization at the molecular level.

Design, synthesis, crystal structure and in vitro cytotoxic properties of a novel Schiff base derived from indole and biphenyl.

A novel and potentially active dihydroorotate dehydrogenase (DHODH) inhibitor, namely 3-({(E)-[(E)-1-(biphenyl-4-yl)ethylidene]hydrazinylidene}methyl)-1H-indole (BEHI) acetonitrile disolvate, C23H19N3·2CH3CN, has been designed and synthesized. The structure of BEHI was characterized by elemental analysis, Q-TOF (quadrupole time-of-flight) MS, NMR, UV-Vis and single-crystal X-ray diffraction. The antitumour activity of the target molecule was evaluated by the MTT method. Results indicated that BEHI exhibited rather potent cytotoxic activity against human A549 (IC50 = 20.5 µM) and mouse breast 4T1 (IC50 = 18.5 µM) cancer cell lines. Meanwhile, to rationalize its potencies in the target, BEHI was docked into DHODH and the interactions with the active site residues were analyzed. Single-crystal structure analysis indicated that hydrogen bonds are present only between BEHI and acetonitrile solvent molecules in the asymmetric unit. The interplay of weak π-π stacking and weak C(N)-H...π interactions between neighbouring BEHI molecules play crucial roles in the formation of the final supramolecular frameworks.