A Novel Cocrystal Explosive of HNIW with Good Comprehensive Properties

In order to improve the safety of the high explosive 2,4,6,8,10,12‐hexanitrohexaazaisowurtzitane (HNIW), we cocrystallized HNIW with the insensitive explosive DNB (1,3‐dinitrobenzene) in a molar ratio 1 : 1 to form a novel cocrystal explosive. Structure determination showed that it belongs to the orthorhombic system with space group Pbca. Therein, layers of DNB alternate with bilayers of HNIW. Analysis of interactions in the cocrystal indicated that the cocrystal is mainly formed by hydrogen bonds and nitro‐aromatic interactions. Moreover, the thermal behavior, sensitivity, and detonation properties of the cocrystal were evaluated. The results implied that the melting point of the cocrystal is 136.6 °C, which means an increase of 45 °C relative that of pure DNB. The predicted detonation velocity and detonation pressure of the cocrystal are 8434 m s⁻¹ and 34 GPa, respectively, which are similar to that of the reported HNIW/TNT cocrystal, but its reduced sensitivity (H₅₀=55 cm) makes it an attractive ingredient in HNIW propellant formulations.     

Preparation and Performance of a BTF/DNB Cocrystal Explosive

An energetic cocrystal containing benzotrifuroxan (BTF) and 1,3‐dinitrobenzene (DNB) in 1 : 1 molar ratio was prepared by slow evaporation of solvent. The structure of the cocrystal was determined by single crystal X‐ray diffraction (XRD). It belongs to the monoclinic crystal system with space group P2₁/c. The performance of the cocrystal was evaluated on the basis of thermolysis, impact sensitivity, and detonation properties. Differential scanning calorimetry (DSC) revealed that the cocrystal has a melting point of 130 °C, which is an increase of 38 °C compared to pure DNB; the decomposition temperature is similar to that of pure BTF. The cocrystal exhibits an impact height with 50 % ignition probability of 88 cm, suggesting a substantial reduction in impact sensitivity compared to pure BTF. Furthermore, the cocrystal is predicted to have a detonation velocity of about 7373 m s⁻¹ and a detonation pressure of about 24 GPa, respectively, indicating excellent detonation performance.     

The development of carbamazepine-succinic acid cocrystal tablet formulations with improved in vitro and in vivo performance

Abstract

The use of soluble cocrystal for delivering drugs with low solubility, although a potentially effective approach, often suffers the problem of rapid disproportionation during dissolution, which negates the solubility advantages offered by the cocrystal. This necessitates their robust stabilization in order for successful use in a tablet dosage form. The cocrystal between carbamezepine and succinic acid (CBZ-SUC) exhibits a higher aqueous solubility than its dihydrate, which is the stable form of CBZ in water. Using this model system, we demonstrate an efficient and material-sparing tablet formulation screening approach enabled by intrinsic dissolution rate measurements. Three tablet formulations capable of stabilizing the cocrystal both under accelerated condition of 40?°C and 75% RH and during dissolution were developed using three different polymers, Soluplus® (F₁), Kollidon VA/64 (F₂) and Hydroxypropyl methyl cellulose acetate succinate (F₃). When compared to a marketed product, Epitol® 200?mg tablets (F₀), drug release after 60?min from formulations F₁ (～82%), F₂ (～95%) and F₃ (～95%) was all higher than that from Epitol® (79%) in a modified simulated intestinal fluid. Studies in albino rabbits show correspondingly better bioavailability of F₁–F₃ than Epitol.     

A DFT-D Study on Structural,Electronic, Thermodynamic,and Mechanical Properties of HMX/MPNO Cocrystal under High Pressure

An investigation on the structural, electronic, thermodynamic, and mechanical properties of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX)/2-methylpyridine-N-oxide (MPNO) cocrystal was carried out from 0 to 100 GPa by using a dispersion-corrected density functional theory (DFT-D) method. Our calculated crystal structure is in excellent agreement with experimental results at ambient pressure. Based on the analysis of lattice parameters, lattice angles, bond lengths, bond angles, and dihedral angles under high pressure, we observe that HMX molecules in the cocrystal bulk are seriously distorted but MPNO molecules remain relatively unchanged. Hydrogen bond lengths are greatly shortened under high pressure. In addition, with the increase in pressure, the bandgap decreases gradually. However, it increases suddenly at 70 GPa. Some important hydrogen bonds between HMX and MPNO are also observed in the density of states spectrum. According to the thermodynamic analysis, this cocrystal is more easily prepared under low pressure. Finally, we characterized its mechanical properties and the results show that this cocrystal is malleable in nature. We expect that this research can provide a fundamental basis for further HMX cocrystal design and preparation.     

Preparation of an Energetic‐Energetic Cocrystal using Resonant Acoustic Mixing

Resonant acoustic mixing (RAM) was applied to the preparation of an energetic‐energetic cocrystal comprised of CL‐20 and HMX in a 2 : 1 mol ratio. We have prepared the cocrystal using the RAM technology in a resource‐efficient manner providing near quantitative yield. The cocrystalline product from the RAM preparation is consistent with the product from solution crystallization.