Crystalline Form
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Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1494
Yan Yan ◽  
Tao Yu ◽  
Huan Zhang ◽  
Jiayu Song ◽  
Chengtun Qu ◽  

Co-precipitation of mineral-based salts during scaling remains poorly understood and thermodynamically undefined within the water industry. This study focuses on investigating calcium carbonate and calcium sulfate mixed precipitation in scaling. Scaling is often observed in the produced water supply as a result of treatment processes. Co-precipitation results were compared with experimental results of a single salt crystallization. Several parameters were carefully monitored, including the electrical conductivity, pH value, crystal morphology and crystal form. The existence of the calcium carbonate scale in the mixed system encourages the loose calcium sulfate scale to become more tightly packed. The mixed scale was firmly adhered to the beaker, and the adhesion of the co-deposition product was located between the pure calcium sulfate scale and the pure calcium carbonate scale. The crystalline form of calcium sulfate was gypsum in both pure material deposition and mixed deposition, while the calcium carbonate scale was stable in calcite form in the pure material deposition. In the co-deposition, apart from calcite form, some calcium carbonate scale crystals had metastable vaterite form. This indicated that the presence of SO42− ions reduced the energy barrier of the calcium carbonate scale and hindered its transformation from a vaterite form to a calcite one, and the increase in HCO3− content inhibited the formation of calcium sulfate scale.

2021 ◽  
Vol 13 (47) ◽  
pp. 141-142
Olga Zhdanova ◽  
Andrey Martusevich ◽  
Nadezhda Mazina ◽  
Fernando Artese ◽  
Micele Troiano ◽  

Introduction: Studying of features of various influences on biosubstrates is interesting to practice, especially in the field of high dilutions (HD) researches. Majority of work in this area include only different methods of spectrophotometry, but informative approaches to their estimation are usually ignored, in particular, a crystallographic analysis is one of them. The present work is aimed at revealing thorough knowledge in the different influences’. The attempts of the crystallogenesis phenomenon are used in pharmacology of 30s years of XX century. At that time the priority problem, in these field, was shown the identification of preparations composition that was founded on suggestion about special type of their crystals. Besides, crystallographic analysis can be useful as way of verification quality. At present the growth of assortment and efficiency of influences’ can be ranked to most significant trends of HD. As a rule, medical biological activity decreasing is accompanied by the parallel growing of electromagnetic, amega and another influence. This fact requires undertaking the careful test of proposed preparation for revision of all sides of its actions, for what the different biological models, first of all laboratory bestial, are often used. Methods: As analyzed samples of  NaCl solutions were taken. The concentration at the solution was 0,1%; 0,9% and 10%  with  the use of solutions of High Dilution of Arnica 6 before and after influence. We used some crystalloscopic methods of biofluids study, such as classical crystalloscopy, allowing install the particularities own crystallogenesis of biosubstrates, and differential teziography, visualizing biofluid initiation potential. Tezigraphic component was investigated by main and additional parameters, characterizing physical and chemical properties of biological fluids. The count of derived factors of the teziocrystalloscopy was realized for full mathematical description and modeling of biosubstratescrystallogenesis. The dehydration picture of solution of any component composition is resulting from multiple parameters. Statistical processing was executed in Microsoft Excel 2003 and program packages SPSS 11.0 and Primer of biostatistics 4.03.    The NaCltesigrafic activity was compared with its  crystalloscopy before and after influence (the estimation in vitro). Results: It was allowed to select the optimum concentration of Na Cl solutions, which had sufficient activity (0,9%  solution). In this connection investigation in vivo (on laboratory mice) was continued with 0,9% concentration only. It is stated that the clear dependency exists between exercised concentrations of solution and crystalloscopic picture, formed by them. In particular, it is revealed that most typical crystalline form (the morphotype) for investigated join is single-crystalline structure of "pyramid" type. The information about facets, formed after influence, can be used for identification of facility with provision for its solution concentration.

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7169
Zhe Yu ◽  
Haozhe Ren ◽  
Yu Zhang ◽  
Youbei Qiao ◽  
Chaoli Wang ◽  

Poly(benzyl malate) (PBM), together with its derivatives, have been studied as nanocarriers for biomedical applications due to their superior biocompatibility and biodegradability. The acquisition of PBM is primarily from chemical routes, which could offer polymer-controlled molecular weight and a unique controllable morphology. Nowadays, the frequently used synthesis from L-aspartic acid gives an overall yield of 4.5%. In this work, a novel synthesis route with malic acid as the initiator was successfully designed and optimized, increasing the reaction yield up to 31.2%. Furthermore, a crystalline form of PBM (PBM-2) that polymerized from high optical purity benzyl-β-malolactonate (MLABn) was discovered during the optimization process. X-ray diffraction (XRD) patterns revealed that the crystalline PBM-2 had obvious diffraction peaks, demonstrating that its internal atoms were arranged in a more orderly manner and were different from the amorphous PBM-1 prepared from the racemic MLABn. The differential scanning calorimetry (DSC) curves and thermogravimetric curves elucidated the diverse thermal behaviors between PBM-1 and PBM-2. The degradation curves and scanning electron microscopy (SEM) images further demonstrated the biodegradability of PBM, which have different crystal structures. The hardness of PBM-2 implied the potential application in bone regeneration, while it resulted in the reduction of solubility when compared with PBM-1, which made it difficult to be dissolved and hydrogenated. The solution was therefore heated up to 75 °C to achieve benzyl deprotection, and a series of partially hydrogenated PBM was sequent prepared. Their optimal hydrogenation rates were screened to determine the optimal conditions for the formation of micelles suitable for drug-carrier applications. In summary, the synthesis route from malic acid facilitated the production of PBM for a shorter time and with a higher yield. The biodegradability, biosafety, mechanical properties, and adjustable hydrogenation widen the application of PBM with tunable properties as drug carriers.

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1440
Yanan Wang ◽  
Yong Wang ◽  
Jin Cheng ◽  
Haibiao Chen ◽  
Jia Xu ◽  

The amorphous form of a drug usually exhibits higher solubility, faster dissolution rate, and improved oral bioavailability in comparison to its crystalline forms. However, the amorphous forms are thermodynamically unstable and tend to transform into a more stable crystalline form, thus losing their advantages. In order to investigate and suppress the crystallization, it is vital to closely monitor the drug solids during the preparation, storage, and application processes. A list of advanced techniques—including optical microscopy, surface grating decay, solid-state nuclear magnetic resonance, broadband dielectric spectroscopy—have been applied to characterize the physicochemical properties of amorphous pharmaceutical solids, to provide in-depth understanding on the crystallization mechanism. This review briefly summarizes these characterization techniques and highlights their recent advances, so as to provide an up-to-date reference to the available tools in the development of amorphous drugs.

B. Zakirov ◽  
M. Zhumanova ◽  
D. Isabaev ◽  
S. Zhumadullaeva

Solubility in the ternary system manganese sulfate - monoethanolamine - water at 25°C was studied by isothermal method. The equilibrium in the system was controlled by liquid phase analysis. True equilibrium in the system was established within 7 hours. The new compound was isolated in crystalline form and identified by the methods of chemical, graphic, X-ray and thermal analyses. It was found that the new compound is a crystalline substance with an individual set of interplanar distances and line intensities. The formation of the new compound NH2C2H4ON-MnSO4-3H2O which was identified by the methods of chemical, graphic and X-ray analyses has been established. Preliminary agrochemical tests of aqueous solution of the new compound showed its positive properties as a stimulant.

2021 ◽  
Vol 22 (22) ◽  
pp. 12406
Emilia Jakubowska ◽  
Bartłomiej Milanowski ◽  
Janina Lulek

Nanosizing is an approach to improve the dissolution rate of poorly soluble drugs. The first aim of this work was to develop nanosuspension of cilostazol with liquid antisolvent precipitation (LASP) and its combination with ultrasound. Second, to systematically study the effect of bottom-up processing factors on precipitated particles’ size and identify the optimal settings for the best reduction. After solvent and stabilizer screening, in-depth process characterization and optimization was performed using Design of Experiments. The work discusses the influence of critical factors found with statistical analysis: feed concentration, stabilizer amount, stirring speed and ultrasound energy governed by time and amplitude. LASP alone only generated particle size of a few microns, but combination with ultrasound was successful in nanosizing (d10 = 0.06, d50 = 0.33, d90 = 1.45 µm). Micro- and nanosuspension’s stability, particle morphology and solid state were studied. Nanosuspension displayed higher apparent solubility than equilibrium and superior dissolution rate over coarse cilostazol and microsuspension. A bottom-up method of precipitation-sonication was demonstrated to be a successful approach to improve the dissolution characteristics of poorly soluble, BCS class II drug cilostazol by reducing its particle size below micron scale, while retaining nanosuspension stability and unchanged crystalline form.

2021 ◽  
Vol 58 (08) ◽  
pp. 54-60
Sanjay S. Pekamwar ◽  
Deepak A. Kulkarni ◽  

This research work was intended to improve the solubility and dissolution of aceclofenac by the development of bicomponent cocrystals. Bicomponent cocrystals of aceclofenac were prepared with ten different cocrystal formers (CCF) by neat grinding techniques. Solubility analysis of cocrystals showed that aceclofenac-salicylic acid cocrystals have comparatively better solubility than the other cocrystals. The solubility of pure aceclofenac (309.23 µg/mL) was found to be improved by seven folds (2424.61 µg/mL) due to the formation of bicomponent crystalline form with salicylic acid. In vitro dissolution also revealed that the immediate release tablet of aceclofenac showed a release of 58.87±1.39 %, while aceclofenacsalicylic acid cocrystal tablet showed drug release of 92.65±1.21 % after 60 minutes. Results of Differential Scanning Colorimetry (DSC), Powdered X-Ray Diffraction (PXRD) and Raman spectroscopic analysis also justified the formation of the novel crystalline form. The developed bicomponent cocrystals of aceclofenac improved the solubility and dissolution of aceclofenac to a significant extent.

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6391
Roman Linko ◽  
Michael Ryabov ◽  
Pavel Strashnov ◽  
Pavel Dorovatovskii ◽  
Victor Khrustalev ◽  

Understanding the interactions of organic donor and acceptor molecules in binary associates is crucial for design and control of their functions. Herein, we carried out a theoretical study on the properties of charge transfer complexes of 1,3,6-trinitro-9,10-phenanthrenequinone (PQ) with 23 aromatic π-electron donors. Density functional theory (DFT) was employed to obtain geometries, frontier orbital energy levels and amounts of charge transfer in the ground and first excited states. For the most effective donors, namely, dibenzotetrathiafulvalene, pentacene, tetrathiafulvalene, 5,10-dimethylphenazine, and tetramethyl-p-phenylenediamine, the amount of charge transfer in the ground state was shown to be 0.134−0.240 e−. Further, a novel charge transfer complex of PQ with anthracene was isolated in crystalline form and its molecular and crystal structure elucidated by single-crystal synchrotron X-ray diffraction.

Molecules ◽  
2021 ◽  
Vol 26 (17) ◽  
pp. 5318
Szymon Sip ◽  
Natalia Rosiak ◽  
Andrzej Miklaszewski ◽  
Patrycja Talarska ◽  
Ewa Dudziec ◽  

The amorphous form of carvedilol phosphate (CVD) was obtained as a result of grinding. The identity of the obtained amorphous form was confirmed by powder X-ray diffraction (PXRD), different scanning calorimetry (DSC), and FT-IR spectroscopy. The process was optimized in order to obtain the appropriate efficiency and time. The crystalline form of CVD was used as the reference standard. Solid dispersions of crystalline and amorphous CVD forms with hydrophilic polymers (hydroxypropyl-β-cyclodextrin, Pluronic® F-127, and Soluplus®) were obtained. Their solubility at pH 1.2 and 6.8 was carried out, as well as their permeation through a model system of biological membranes suitable for the gastrointestinal tract (PAMPA-GIT) was established. The influence of selected polymers on CVD properties was defined for the amorphous form regarding the crystalline form of CVD. As a result of grinding (four milling cycles lasting 15 min with 5 min breaks), amorphous CVD was obtained. Its presence was confirmed by the “halo effect” on the diffraction patterns, the disappearance of the peak at 160.5 °C in the thermograms, and the changes in position/disappearance of many characteristic bands on the FT-IR spectra. As a result of changes in the CVD structure, its lower solubility at pH 1.2 and pH 6.8 was noted. While the amorphous dispersions of CVD, especially with Pluronic® F-127, achieved better solubility than combinations of crystalline forms with excipients. Using the PAMPA-GIT model, amorphous CVD was assessed as high permeable (Papp > 1 × 10−6 cm/s), similarly with its amorphous dispersions with excipients (hydroxypropyl-β-cyclodextrin, Pluronic® F-127, and Soluplus®), although in their cases, the values of apparent constants permeability were decreased.

2021 ◽  
Vol 14 (3) ◽  
pp. 290-301
Galina V. Novikova ◽  
Darya I. Tsyplenkova ◽  
Alexander A. Kuzubov ◽  
Oksana A. Kolenchukova ◽  

The calcium complex of ceftriaxone was synthesized and characterized by elemental, atomic-emission analysis, TGA, IR spectroscopy and density functional theory calculations. The luminescence and antibacterial properties of the ceftriaxone disodium and calcium complex were investigated. Ca(II) complex was obtained in a crystalline form, cell parameters of the compound were determined. Ceftriaxone was coordinated to the calcium ion by the oxygen of the triazine cycle in the 6th position, the nitrogen of the amine group of the thiazole ring, and the oxygens of the lactam carbonyl and carboxylate groups. The complex of Ca(II) with ceftriaxone was screened for antibacterial activity against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa, and the results were compared with the activity of ceftriaxone disodium salt

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