Platensimycin-berberine chloride co-amorphous drug system: Sustained release and prolonged half-life

Insight into Formation, Synchronized Release and Stability of Co-Amorphous Curcumin-Piperine by Integrating Experimental-Modeling Techniques

Intermolecular interactions between drug and co-former are crucial in the formation, release and physical stability of co-amorphous system. However, the interactions remain difficult to investigate with only experimental tools. In this study, intermolecular interactions of co-amorphous curcumin-piperine (i.e., CUR-PIP CM) during formation, dissolution and storage were explored by integrating experimental and modeling techniques. The formed CUR-PIP CM exhibited the strong hydrogen bond interaction between the phenolic OH group of CUR and the CO group of PIP as confirmed by FTIR, ss 13C NMR and molecular dynamics (MD) simulation. In comparison to crystalline CUR, crystalline PIP and their physical mixture, CUR-PIP CM performed significantly increased dissolution accompanied by the synchronized release of CUR and PIP, which arose from the greater interaction energy of H2O-CUR molecules and H2O-PIP molecules than CUR-PIP molecules, breaking the hydrogen bond between CUR and PIP molecules, and then causing a pair-wise solvation of CUR-PIP CM at the molecular level. Furthermore, the stronger intermolecular interaction between CUR and PIP was revealed by higher binding energy of CUR-PIP molecules, which contributed to the excellent physical stability of CUR-PIP CM over amorphous CUR or PIP. The study provides a unique insight into the formation, release and stability of co-amorphous system from MD perspective. Meanwhile, this integrated technique can be used as a practical methodology for the future design of co-amorphous formulations.

Drug-drug co-amorphous systems: An emerging formulation strategy for poorly water-soluble drugs

Overcoming the poor water solubility of small-molecule drugs is a major challenge in the development of clinical pharmaceuticals. Amorphization of crystalline drugs is a highly effective strategy to improve their aqueous solubility. However, amorphous drugs are thermodynamically unstable and likely to crystallize during manufacturing and storage. Recently, drug-drug co-amorphous systems have emerged as a novel strategy to not only enable enhanced dissolution and physical stability of the individual drugs within the system but also to provide a strategy for combination therapy of the same or different clinical indications. This review serves to highlight advances in the methods used to manufacture and characterize drug-drug co-amorphous systems, summarize drug-drug co-amorphous applications reported in recent decades, and provide an outlook on future possibilities and perspectives.

Inhibiting Osteolytic Breast Cancer Bone Metastasis by Bone-Targeted Nanoagent via Remodeling the Bone Tumor Microenvironment Combined with NIR-II Photothermal Therapy

Bone is one of the prone metastatic sites of patients with advanced breast cancer. The "vicious cycle" between osteoclasts and breast cancer cells plays an essential role in osteolytic bone metastasis from breast cancer. In order to inhibit bone metastasis from breast cancer, NIR-II photoresponsive bone-targeting nanosystems (CuP@PPy-ZOL NPs) are designed and synthesized. CuP@PPy-ZOL NPs can trigger the photothermal-enhanced Fenton response and photodynamic effect to enhance the photothermal treatment (PTT) effect and thus achieve synergistic anti-tumor effect. Meanwhile, they exhibit a photothermal enhanced ability to inhibit osteoclast differentiation and promote osteoblast differentiation, which reshaped the bone microenvironment. CuP@PPy-ZOL NPs effectively inhibited the proliferation of tumor cells and bone resorption in the in vitro 3D bone metastases model of breast cancer. In a mouse model of breast cancer bone metastasis, CuP@PPy-ZOL NPs combined with PTT with NIR-II significantly inhibited the tumor growth of breast cancer bone metastases and osteolysis while promoting bone repair to achieve the reversal of osteolytic breast cancer bone metastases. Furthermore, the potential biological mechanisms of synergistic treatment are identified by conditioned culture experiments and mRNA transcriptome analysis. The design of this nanosystem provides a promising strategy for treating osteolytic bone metastases.

Maleic Acid as a Co-Former for Pharmaceutically Active GABA Derivatives: Mechanochemistry or Solvent Crystallization?

In this study, we compare the mechanochemical and classical solvent crystallization methods for forming maleates of GABA and its pharmaceutically active derivatives: Pregabalin, Gabapentin, Phenibut, and Baclofen. Common characterization techniques, like powder and single crystal X-ray diffraction, IR-spectroscopy, differential scanning calorimetry, thermogravimetric analysis and ¹H-NMR spectroscopy, are used for the evaluation of structural and physicochemical properties. Our work shows that maleate formation is possible with all investigated target compounds. Large increases in solubility can be achieved, especially for Pregabalin, where up to twentyfold higher solubility in its maleate compared to the pure form can be reached. We furthermore compare the mechanochemical and solvent crystallization regarding quickness, reliability of phase production, and overall product quality. A synthetic route is shown to have an impact on certain properties such as melting point or solubility of the same obtained products, e.g., for Gabapentin and Pregabalin, or lead to the formation of hydrates vs. anhydrous forms. For the GABA and Baclofen maleates, the method of crystallization is not important, and similarly, good results can be obtained by either route. In contrast, Phenibut maleate cannot be obtained pure and single-phase by either method. Our work aims to elucidate promising candidates for the multicomponent crystal formation of blockbuster GABA pharmaceuticals and highlight the usefulness of mechanochemical production routes.

Co-amorphous formulation of dipyridamole with p-hydroxybenzoic acid: Underlying molecular mechanisms, physical stability, dissolution behavior and pharmacokinetic study

Coamorphization has been proven to be an effective approach to improve bioavailability of poorly soluble active pharmaceutical ingredients (APIs) by virtue of solubilization, and also contributes to overcome limitation of physical stability associated with amorphous drug alone. In current work, a co-amorphous formulation of dipyridamole (DPM), a poor solubility drug, with p-hydroxybenzoic acid (HBA) was prepared and investigated. At a molar ratio of 1:2, DPM and HBA were melted result in the formation of a binary co-amorphous system. The DPM-HBA co-amorphous was structurally characterized by powder X-ray diffraction (PXRD), temperature modulated differential scanning calorimetry (mDSC), high performance liquid chromatography (HPLC) and solution state ¹H nuclear magnetic resonance (¹H NMR). The molecular mechanisms in the co-amorphous were further analysed via Fourier-transform infrared (FTIR) and Raman spectroscopies, as well as density functional theory (DFT) calculation. All the results consistently revealed the presence of hydrogen bonding interactions between -OH of DPM and -COOH on HBA. Accelerated test and glass transition kinetics showed excellent physical stability of DPM-HBA co-amorphous compared with amorphous DPM along with glass transition temperatures (T_g). The phase-solubility study indicated that complexation occurred between DPM and HBA in solution, which contributed to the solubility and dissolution enhancement of DPM in co-amorphous system. Pharmacokinetic study of co-amorphous DPM-HBA in mouse plasma revealed that the DPM exhibited 1.78-fold and 2.64-fold improvement in AUC_0‑∞ value compared with crystalline and amorphous DPM, respectively. This current study revealed coamorphization is an effective approach for DPM to improve the solubility and biopharmaceutical performance.