Application of cocrystal separation technology in the separation and purification of genistein-puerarin-daidzein ternary system / 药学学报

Cocrystal separation technology is a technology that utilizes coformers to selectively form cocrystals with target compounds and separate them from mixed systems. Our study used puerarin (PUE), daidzein (DDZ), and genistein (GEN) as model drugs, which have similar structures and are the main isoflavones in Pueraria lobata root. The separation and purification processes in the modern traditional Chinese medicine (TCM) of these three components use conventional column chromatography, recrystallization, and other technologies, which have the issues of lengthy separation cycles, high solvent consumption, and inefficient preparation. Different with existing separation technology, our team used the early-found cocrystal separation method to design a step-by-step extraction and separation experiment of GEN-PUE-DDZ ternary mixture. Caffeine and L-proline were added to the mixed system in turn, GEN-caffeine cocrystal and PUE-proline cocrystal were prepared by suspension method. The cocrystals precipitated out of the solution. The purities of the GEN-caffeine cocrystal and the PUE-proline cocrystal could achieve 93% (the purity of GEN) and 99% (the purity of PUE). Besides, the purity of DDZ could also be increased by 6.76 times. This study proposed a simple operating, low cost and wide application range separation method different from the traditional separation method and realized the separation of structurally similar chemical components in TCM, laying a foundation for the application of cocrystal technology in the separation and refining of TCM.

Infrared spectral band screening based on partial least squares is used for the quantitative analysis of mannitol-calcium chloride cocrystal / 药学学报

Mannitol-calcium chloride metal organic framework (MOF) cocrystal significantly improved the tabletability of β-mannitol and could be developed as a new tablet filler. However, mannitol monomer was found in the product during the scale-up production of the excipient, which significantly affected the functional properties of the excipient. In this study, we intend to quantify the multi-component eutectic system of mannitol-calcium chloride. In this experiment, the MOF cocrystal excipient mannitol-calcium chloride cocrystal was used as the model compound, and infrared spectrum was collected. Based on partial least squares regression (PLSR) method, the abnormal bands were removed and the spectrum was preprocessed by normalization. The quantitative correction model of mannitol-calcium chloride MOF cocrystal content in cocrystal excipients was established and compared by two different variable screening methods, genetic algorithm (GA) and competitive adaptive reweighting algorithm (CARS). Two different variable screening methods, GA method and CARS method, were used to screen out 160 and 14 variables, respectively. The mannitol-calcium chloride cocrystal model established by CARS-PLSR method had the best performance, and the average relative error (MRE) and corrected root mean square error (RMSEC) of the model were 0.008 8 and 0.892 5, respectively, the determination coefficient (R2) of the model was increased from 0.978 3 to 0.994 4. The quantitative method of eutectic system established in this study has high prediction accuracy, fast detection speed and good stability, which is of great significance for optimizing the preparation process conditions and quality control methods of such eutectic excipients.

Study on preparation and in vivo safety of progesterone cocrystal / 中国药房

OBJECTIVE To prepare progesterone-2-chloro-4-nitroaniline cocrystal （CNA） so as to improve the solubility of progesterone and primarily evaluate the safety of the progesterone cocrystal in vivo. METHODS Using progesterone as the main body and CNA as the ligand， progesterone-CNA cocrystal was prepared with solvent evaporation method. The cocrystal was characterized by X-ray single crystal diffraction， X-ray powder diffraction （XRPD）， differential scanning calorimetry （DSC） and Fourier transform infrared spectroscopy （IR）. The dissolution rate of cocrystal was compared with those of progesterone and physical mixture. Forty-eight female KM mice were randomly divided into normal group （phosphate buffer containing 0.1% dimethyl sulfoxide）， progesterone group （16 mg/kg）， CNA group （9 mg/kg）， progesterone-CNA cocrystal low-dose， medium- dose and high-dose groups （6， 12.5， 25 mg/kg）， with 8 mice in each group. They were given relevant medicine/solvent intramuscularly， once a day， for consecutive 14 d. The safety of cocrystal was evaluated primarily by determining/observing the changes in body weight， organ index， tissue morphology， blood routine indicators， and liver and kidney function indicators. RESULTS The new crystal structure in the X-ray single crystal diffraction results， the new characteristic peak in the XRPD pattern， the change of melting point in the DSC results， and the change of the characteristic peak position in the range of 3 500- 2 750 cm－1 and 1 700-1 250 cm－1 in the infrared spectrum all Δ 基金项目国家重点研发计划项目（No.2022YFC3502100） indicated that progesterone-CNA cocrystal was successfully ＊第一作者 硕士研究生 。研究方向 ：药物制备技术与工艺 。 prepared， and the dissolution rate of cocrystal was more than E-mail：SWB_1221@163.com # 通信作者教授，硕士生导师，博士。研究方向：药物制备技术与 twice that of the progesterone raw material drug. The results of 工艺。E-mail：wuxx-415@126.com in vivo safety experiments showed that the mortality rate of all 中国药房 2023年第34卷第13期 China Pharmacy 2023 Vol. 34 No. 13 · 1567 · groups was zero. Compared with normal group， uterine indexes of mice in progesterone group and progesterone-CNA cocrystal groups were significantly increased （P＞0.05）， and endometrium was also thickened； there was no statistical difference in the changes of body mass， liver and kidney function， liver index， kidney index， the number of leukocyte， lymphocyte and neutrophil in routine blood test among those groups （P＞0.05）， and the morphology of liver and kidney tissue has also no significant difference. However， the number of plasma red blood cells in the progesterone group decreased significantly （P＜0.05）， and there was no statistical significance in the number difference of red blood cells among progesterone-CNA cocrystal groups （P＞0.05）. CONCLUSIONS The progesterone-CNA cocrystal is successfully prepared with good safety in vivo， which significantly improve the solubility of progesterone.

Pharmaceutical co-crystals of posaconazole for improvement of physicochemical properties

Abstract Posaconazole exerts an extended spectrum of antifungal activity against various strains of clinically relevant moulds and yeasts. In recent years, antifungal triazole posaconazole has become increasingly important for the prophylaxis and treatment of systemic mycoses. After oral administration of posaconazole, absolute bioavailability has been estimated to range from 8% to 47%. Pharmaceutical co-crystallization is a promising approach for improving dissolution rate or manipulating other physical properties of API. The objective of this study is to improve the dissolution rate of posaconazole by co-crystallization. A 1:1 stoichiometric co-crystals of adipic acid were prepared by solvent assisted grinding method. The prepared co-crystals were subjected to solid-state characterization by FTIR, PXRD and DSC studies. The physicochemical properties of posaconazole and co-crystals were assessed in terms of melting point, flowability and dissolution rate. The results indicated improvement in flow property and dissolution rate. In vitro dissolution profile of co-crystals showed a significant increased dissolution of posaconazole from initial period in 0.1 N hydrochloric acid solution. The dissolution efficiency for posaconazole-adipic acid co-crystal was 61.65 % against posaconazole, 46.58 %. Thus, co-crystallization can be a promising approach to prepare posaconazole-adipic acid co-crystals with improved physicochemical properties.

Effects of polyvinylpyrrolidone and poly (ethylene glycol) on preparation of ibuprofen pharmaceutical cocrystal

Abstract In this study, we investigated the effects of polymers on the pharmaceutical cocrystal formation process. Ibuprofen (IBU) was selected as the active pharmaceutical ingredient (API), nicotinamide (NIC) and saccharin (SAC) as the cocrystal coformer (CCF), ethanol/water as the solvent, polyvinylpyrrolidone (PVP) and poly (ethylene glycol) (PEG) as the representative polymers. We prepared IBU-NIC and IBU-SAC cocrystals in ethanol-water cosolvent in the absence or presence of polymers. Cocrystal screening products were characterized by FTIR, DSC, PXRD, and HPLC. The results showed that the mixture of IBU and IBU-NIC cocrystal can be prepared in ethanol-water cosolvent without polymers. The addition of PVP facilitates the formation of pure IBU-NIC cocrystal; however, no cocrystal was formed in PEG solutions. SAC could not cocrystallize with IBU in the ethanol-water solvent in the absence of polymers. Neither PVP nor PEG could facilitate the formation of the IBU-SAC cocrystal.

Pharmaceutical cocrystals: A review of preparations, physicochemical properties and applications

Pharmaceutical cocrystals are multicomponent systems in which at least one component is an active pharmaceutical ingredient and the others are pharmaceutically acceptable ingredients. Cocrystallization of a drug substance with a coformer is a promising and emerging approach to improve the performance of pharmaceuticals, such as solubility, dissolution profile, pharmacokinetics and stability. This review article presents a comprehensive overview of pharmaceutical cocrystals, including preparation methods, physicochemical properties, and applications. Furthermore, some examples of drug cocrystals are highlighted to illustrate the effect of crystal structures on the various aspects of active pharmaceutical ingredients, such as physical stability, chemical stability, mechanical properties, optical properties, bioavailability, sustained release and therapeutic effect. This review will provide guidance for more efficient design and manufacture of pharmaceutical cocrystals with desired physicochemical properties and applications.

Establishment of a cocrystal characterization method for sacubitril valsartan sodium / 药学学报

Sacubitril valsartan sodium (LCZ696) is an ionic cocrystal drug. The purpose of this study was to explore the cocrystal features of LC696 by establishing a variety of characterization methods, and thus provide basic research data for effective quality control. The cocrystal characteristics of LCZ696 and its tablets were identified by applying analytical means including powder X-ray diffraction (PXRD), fourier transform infrared spectroscopy (FTIR), Raman spectra (RM), differential scanning calorimetry (DSC) and solid-state nuclear magnetic resonance spectroscopy (ssNMR). The crystalline water and hygroscopicity of LCZ696 were analyzed by thermogravimetric analysis (TGA), dynamic vapor sorption (DVS), hygroscopicity test and Karl Fischer reaction method. The results show that PXRD, FTIR, DSC and ssNMR can effectively distinguish the features of LCZ696 cocrystal, sacubitril monomer, valsartan monomer, and sacubitril-valsartan (1∶1) mixture. RM can be used as a supplementary approach. Combined with the analysis by TGA, DVS, hygroscopicity test and Karl Fischer reaction method results, LCZ696 contains 2.5 crystalline water molecules and is very hygroscopic; we recommend that LCZ696 be stored in an environment with a relative humidity below 60%. By characterizing the crystal features we can establish quality control measure and evaluate the stability of the drug tablets. This study provides data in support for the establishment of the LCZ696 quality standard.

Druggability enhancement by modification of physicochemical properties of drugs via crystal engineering / 药学学报

The solubility/dissolution, hygroscopicity and mechanical properties of drug candidates have a profound effect on oral bioavailability, processability and stability. The physicochemical properties of crystalline drug are closely related to inner crystal structure. Crystal engineering technologies, as strategies of altering the crystal structure and tailoring physicochemical properties at molecular level, possess the potential of enhancing the pharmaceutical performance of product. The current article reviewed the modification of drug solubility/dissolution, hygroscopicity and mechanical properties by crystal engineering technologies through polymorphic selection, amorphization/co-amorphization, as well as co-crystallization, which provided a reference for the applications of pharmaceutical crystallography in improving physicochemical properties and druggability.

Advances in drug-drug complexes based on the crystal engineering design / 药学学报

Drug-drug complexes play important roles in improving the physicochemical properties of drugs including the solubility, dissolution rate and stability of the active pharmaceutical ingredients (APIs). In this paper, the design, synthesis, characterization, changes in physicochemical and pharmacologic properties, structural polymorphisms and the research and development pipelines of a variety of drug-drug cocrystals/salts synthesized based on the crystal engineering design are reviewed. This may provide theoretical support for the development of the new solid-state combinational drugs.

Preparation and Characterization of Naringenin Nicotinamide Co-crystal / 中国药学杂志

OBJECTIVE: To prepare a novel naringenin co-crystal to improve the poor water solubility of the compound. METHODS: Solvent volatilization method was used to prepare naringenin nicotinamide co-crystal, with ethyl acetate as solvent. It is characterized by the technology of infrared spectroscopy (IR), differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD), scanning electron microscopy (SEM) and other techniques. RESULTS: By measuring the equilibrium solubility of different pH solutions, it was found that the naringenin nicotinamide co-crystal has a significantly improved equilibrium solubility compared with naringenin. CONCLUSION: This method can improve the solubility of naringenin, which is simple and easy, and lays the foundation for further study of naringenin co-crystal.

Improving Solubility of Famotidine by Cocrystal Synthesis with Nicotinic Acid / 中国药学杂志

OBJECTIVE: This study was focused on obtaining and characterizing cocrystal of famotidine to improve its solubility. METHODS: A new cocrystal of famotidine with nicotinic acid(FAM-NIC) was obtained by solution evaporation. And the FAM-NIC cocrystal was characterized by single crystal X-ray diffraction, powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR). In addition, the solubility and stability of cocrystal were studied. RESULTS: The asymmetric unit of FAM-NIC consisted of one molecule of famotidine, nicotinic acid, and water, and they were connected through hydrogen bonds. FAM-NIC had unique thermal, spectroscopic, X-ray diffraction, and solubility properties that differed from famotidine. Dissolution studies of the cocrystal showed a 4.2-fold increase of famotidine solubility, and FAM-NIC didn′t change the stability of famotidine in artificial gastric juice, at high humidity, at high temperature, and under illumination. CONCLUSION: The new cocrystal of famotidine with nicotinic acid obviously enhanced the solubility of famotidine.And the RESULTS can be useful for improving solubility of drugs by cocrystal synthesis.

Preparation of indomethacin-nicotinamide cocrystal by hot melt extrusion and its release in vitro / 中国药科大学学报

@#Abstract The indomethacin-nicotinamide cocrystal was prepared by hot melt extrusion(HME)to improve the dissolution of indomethacin in vitro. The optimum preparation conditions were investigated using temperature and rotate speed as variables. Thermogravimetric analysis(TGA), determination of content and determination of related substances were performed to evaluate the thermal stability of indomethacin during the process. Cocrystal was also prepared by solution crystallization from acetonitrile. The products obtained by the two methods were characterized by differential scanning calorimetry(DSC), Fourier transform infrared(FTIR)and powder X-ray diffraction(PXRD). The solubility and dissolution advantages of cocrystal were evaluated. The results showed that the HME method could successfully prepare the indomethacin-nicotinamide cocrystal at 115 °C and eutectic mixture was formed during the process. The cocrystal significantly improved the solubility and dissolution of indomethacin in deionized water, with pH 5. 5 and pH 6. 8 phosphate buffer. The preparation of poorly soluble drug cocrystal by HME can significantly improve its solubility, providing new idea for the development of poorly soluble drugs and HME technology.

Research Progresses on Pharmaceutical Co-crystals of the Cardiovascular and Cerebrovascular Diseases Treatment Drugs / 医药导报

The pharmaceutical co-crystal has attracted a lot of attention in recent years as a new direction in the research of polymorphism drugs. The research on pharmaceutical co-crystal has scientific significance for improving the solubility, bioavailability and physical or chemical stability of drugs. In this paper, from the perspective of drugs for the treatment of cardiovascular diseases(including five major types: heart failure, hypertension, coronary heart disease and arrhythmia, stroke) , the latest research results of pharmaceutical co-crystal reported in recent years are reviewed, hope to provide reference for the follow-up research and promote the development of pharmaceutical co-crystal in China.

The effects of pH, surfactant, ion concentration, coformer, and molecular arrangement on the solubility behavior of myricetin cocrystals

Pharmaceutical cocrystals are a promising technology that can be used to improve the solubility of poor aqueous compounds. The objective of this study was to systematically investigate the solubility of myricetin (MYR) cocrystals, including their kinetic solubility, thermodynamic solubility, and intrinsic dissolution rate (IDR). The effects of pH, surfactant, ion concentration, and coformers on the cocrystal solubility were evaluated. Furthermore, single crystal structures of MYR, myricetin-isonicotinamide (MYR-INM) and myricetin-caffeine (MYR-CAF) cocrystals were analyzed to discuss the possible reasons for the enhancement of cocrystal solubility from the perspective of the spatial structure. The results indicated that the kinetic solubility of MYR cocrystals was modulated by pH and cocrystal coformer (CCF) ionization in buffer solution, while it primarily depended on the CCF solubility in pure water. In addition, the solubility of MYR cocrystals was increased in a concentration dependent fashion by the surfactant or ion concentration. The thermodynamic solubility of MYR-INM (1:3) cocrystals decreased with the increases of the pH value of the dissolution media. The IDR of MYR cocrystals was faster than that of MYR in the same medium and extremely fast in pH 4.5 buffer. The improved solubility of MYR cocrystals was probably related to the alternate arrangements of MYR and INM/CAF molecules and increased intermolecular distance. The present study provides some references to investigate the solubility behavior of pharmaceutical cocrystals.

Hirshfeld Surface and Structure Analysis of Two Co-crystal of Isonicotinic Acid Hydrazide / 医药导报

Objective Two co-crystals of isonicotinic acid hydrazide(INH)-malonic acid and INH-glutaric acid were prepared.The formation mechanism and intermolecular interaction were studied. Methods Three-dimensional structure of 2 co-crystals were obtained though single crystal X-ray diffraction(SXRD), and intermolecular interaction was analyzed using Hirshfeld surface method. Results INH-malonic acid crystalized in stoichiometric ratio of 1:0.5,while INH-glutaric acid in 1:1.Two co-crystals maintain their stable arrangement in space by hydrogen bond and van der Waals force. Conclusion With the existence of pyridine ring and carbohydrazide group in INH,which mainter-molecular interaction in co-crystal can be directly and clearly revealed by Hirshfeld surface analysis.

Enhanced dissolution and oral bioavailability of baicalein by cocrystallization / 中国药科大学学报

@#Baicalein(BE), a natural flavonoid mainly extracted from Radix Scutellaria, has comprehensive pharmacological actions such as anti-inflammation, anti-virus and anti-cancer activities. It belongs to BCS class II compound with relatively low oral bioavailability. The current study aims to improve its aqueous solubility and dissolution and hence to enhance its oral absorption by cocrystallization technique. Slurry crystallization method was employed to prepare baicalein cocrystal with co-former caffeine(CA), followed by physicochemical characterizations with DSC, XRPD and FTIR. Compared to BE and physical mixture of BE and CA, BE-CA cocrystal had a significantly higher dissolution of BE. In addition, in comparison to BE, this cocrystal achieved reduced time to peak(tmax)as well as significantly higher peak plasma concentrations(cmax)and area under the curve(AUCs)for both BE and its active metabolite baicalin(BI)in rats, suggesting enhanced the oral bioavailability of BE.

Anti-inflammatory Effect of the Luteolin-4, 4' -dipyridy Co-crystal on Macrophage RAW264.7 in Mice / 中国药房

OBJECTIVE: To study anti-inflammatory effect and mechanism of the luteolin · 4, 4' -dipyridy co-crystal.METHODS: Using macrophage RAW264. 7 of normal mice as control, the inflammation model was established with lipopolysaccharide (LPS) -induced RAW264. 7 cells. MTT assay was used to detect cells activity 2 h after treatment of different concentrations of luteolin (10, 20, 40, 80 μmol/L), 4, 4' -dipyridy (10,20, 40,80 μmol/L) and luteolin·4, 4' -dipyridy co-crystal (10, 20, 40, 80 μmol/L). The mRNA expression of iNOS and COX-2 in RAW264. 7 cells at 40 μmol/L were determined by qRT-PCR. The protein expression of TNF-α and IL-6 in RAW264. 7 cells at 40 μmol/L were determined by ELISA. The protein expression of NF-κB p65 in RAW264. 7 cells at 40 μmol/L were determined by Western bolt. RESULTS: Compared with normal cells, the activity of RAW264. 7 cells was decreased significantly after induced by LPS (P<0. 01); mRNA expression of iNOS and COX-2, protein expression of TNF-α, IL-6 and NF-κB p65 were increased significantly (P<0. 01). Both luteolin and luteolin · 4, 4' -dipyridy co-crystal could enhance the activity of RAW264. 7 cells after induced by LPS (P<0. 05 or P<0. 01) in concentration-dependent manner. 4, 4' -dipyridy had no significant effect on the activity of RAW264. 7 cells after induced by LPS. After luteolin and luteolin· 4, 4' -dipyridy co-crystal at 40 μmol/L, mRNA expression of iNOS and COX-2, protein expression of TNF-α, IL-6 and NF-κB p65 in RAW264. 7 cells after induced by LPS were decreased significantly (P<0. 05 or P<0. 01); the luteolin · 4, 4' -dipyridy co-crystal was better than luteolin (P<0. 05 or P<0. 01). CONCLUSIONS: The luteolin·4, 4' -dipyridy co-crystal can inhibit the generation of inflammatory factors by down-regulating NF-κB signal, and its anti-i nflammatory effect is better than luteolin.

Enhanced dissolution and intestinal absorption of adefovir dipivoxil by cocrystal formation with acetaminophen / 药学学报

In current study, adefovir dipivoxil (AD)-acetaminophen (AP) cocrystal (molar ratio, 1:1) was prepared by slow evaporation from acetonitrile, followed by physicochemical characterizations using differential scanning calorimetry, powder X-Ray diffraction and Fourier transform infrared spectroscopy. Molecular modeling showed that the phosphoester group of AD was connected with the amide group of AP through hydrogen bonds. In comparison to crystalline AD, the solubility and dissolution rate of AD from AD-AP cocrystal were significantly enhanced by 1.5-fold and 1.6-fold, respectively. In addition, based on the rat single-pass intestinal perfusion study, the permeabilities of AD in various intestinal sections (i.e., duodenum, jejunum, ileum and colon) were significantly improved (e.g., about 3-fold enhancement in duodenum) after cocrystallization with AP by inhibiting P-glyprotein mediated efflux of AD, which will benefit absorption in vivo and subsequent oral bioavailability of poorly permeable drug AD.

Thermodynamic studies of naringenin-isonicotinamide cocrystals / 药学学报

The purpose of this study was to investigate the thermodynamics of naringenin (NAR)-isonicotinamide (INT) cocrystal (stoichiometric ratio, 1∶2) formed in different solvents. The dissolution behavior of cocrystal was explored in the water. Solubility of NAR-INT cocrystals under various temperatures were measured, followed by fitting the complexation model to calculate the thermodynamic parameters solubility products (Ksp), complexation constants (K12) and Gibbs energy change (ΔG) of cocrystal during formation progress. Ternary phase diagrams (TPDs) of the NAR-INT-solvent systems under various temperatures were plotted. Based on the non-linear simulation, 1∶2 complexation model was well fitted to the NAR-INT cocrystal formation in ethanol, isopropanol and ethyl acetate, while no complexation model was more suitable for that in methanol. The cocrystallization reaction was exothermic and spontaneous (ΔG H S Ksp increased while K12 decreased when increasing temperature, suggesting that the two components could cocrystallize more easily at the lower temperature. In comparison to TPDs in other solvents, the area of homogeneous liquid phase in ethyl acetate was the smallest, indicating the easiest formation of NAR-INT cocrystal in ethyl acetate. The current study provides a theoretical foundation for preparation and optimization of scale-up NAR-INT cocrystals.

Design, synthesis and structure-activity relationship studies of human dihydroorotate dehydrogenase inhibitors / 药学学报

In this study, 1-(3-(4-chlorophenyl)-5-methylthio-1H-1,2,4-triazol-1-yl)-butan-1-one discovered previously in our lab was selected as a inhibitor of human dihydroorotate dehydrogenase (HsDHODH) for structural optimization. The co-crystal of HsDHODH with the hit was obtained and analyzed for guiding the subsequent structural optimization. As a result, a series of novel triazole derivatives were designed and synthesized as potent HsDHODH inhibitors. Among them, compound (3-(4-chlorophenyl)-5-ethylthio-1H-1,2,4-triazol-1-yl)-furan-2-yl-methanone displayed high potency in the inhibition of HsDHODH with an IC50 value of 1.50 μmol·L-1. Meanwhile, the structure-activity relationships were analyzed based on the biological data and the co-crystal structure. These results provide a valuable reference for optimization of 1H-1,2,4-triazole derivatives as HsDHODH inhibitors in the future.