scholarly journals The Effect of Solvents and Drying Temperature on the Physicochemical Properties of Darunavir and Darunavir Ethanolate Substances

2021 ◽  
Vol 10 (1) ◽  
pp. 67-73
Author(s):  
S. A. Zolotov ◽  
I. A. Dain ◽  
N. B. Demina ◽  
A. S. Zolotova ◽  
E. S. Ponomarev
Keyword(s):  
Ir Spectroscopy ◽  
Physicochemical Properties ◽  
Scanning Calorimetry ◽  
Drying Temperature ◽  
X Ray ◽  
Effect Of Solvents ◽  
Solvent Type ◽  
Study Results ◽  
Darunavir Ethanolate ◽  
The Impact

Introduction. Usage of aggressive conditions (solvents, high temperature, etc.) in a dosage form manufacturing can lead to a change in the properties of a pharmaceutical substance. Darunavir (D) amorphous and darunavir ethanolate (DE) crystalline both have poor solubility, ability to pseudopolymorphism and are sensitive to high temperatures.Aim. Study the effect of solvents and drying temperature on the physicochemical properties of D and DE substancesMaterials and methods. D (Mylan Laboratories Limited), DE (Mylan Laboratories Limited), D (reference standard) 99,9 % (MSN Pharmachem Private Limited). D and DE weighed quantity was suspended in one of the solvents via magnetic stirrer and was dried via universal oven. Powder X-ray diffraction of dried samples was carried out via automatic powder diffractometer. Using DSC thermal properties of the samples were studied. Crystalline samples were examined using IR spectroscopy. Identification of D and DE was performed by HPLC method.Results and discussion. This article summarizes study results of the investigation of various solvents and drying temperature influence on the physicochemical properties of D and DE are presented. The impact of solvent type and drying temperatures in physicochemical properties of the APIs was studied by X-ray powder diffraction, differential scanning calorimetry, IR spectroscopy and HPLC methods. It was shown, that solvent type and drying temperatures can result in the presence of crystalline D solvates or amorphous D.Conclusion. To obtain the final drug containing as an API amorphous D, which perform better dissolution, one of the enlisted solvents can be used: dichloromethane, chloroform and heptane. In such case the intermediate product drying should be performed at not exceeding the solvent boiling point temperatures. In case of ethanol, methanol, acetone and tetrahydrofuran drying phase can be performed at temperatures, that are higher than melting points of obtained pseudopolymorphs. For the utilization of DE as an API only ethanol usage is efficient and drying temperature should not exceed 73.4 °C.

A Study of the Interactions Between Oligoamidephosphate (OAPh) and Curatives in a Sulphenamide-Accelerated Sulphur Vulcanizing System

1999 ◽  
Vol 19 (2) ◽  
pp. 95-108 ◽  
Author(s):  
Todorka G. Vladkova ◽  
Alexander Chr. Alaminov ◽  
Milka G. Pankova
Keyword(s):  
Differential Scanning Calorimetry ◽  
Zinc Oxide ◽  
Ir Spectroscopy ◽  
Room Temperature ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Sulphur Vulcanization

Abstract The possible interactions between oligoamidephosphate (OAPli) and the curatives of a sulphenamide-accelerated sulphur vulcanizing system were studied by differential scanning calorimetry, IR-spectroscopy, and X-ray analysis. The interactions in double mixtures were between OAPh and zinc oxide (ZnO) and OAPh and sulphur. The OAPh/ZnO interaction that starts at room temperature seems to be the key for understanding the peculiarities of sulphenamide-accelerated sulphur vulcanization in the presence of OAPh.

scholarly journals Effect of Solid Forms on Physicochemical Properties of Valnemulin

Crystals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 675 ◽  
Author(s):  
Jinbo Ouyang ◽  
Jian Chen ◽  
Limin Zhou ◽  
Fangze Han ◽  
Xin Huang
Keyword(s):  
Organic Acids ◽  
Physicochemical Properties ◽  
Excess Enthalpy ◽  
Vapor Sorption ◽  
Dynamic Vapor Sorption ◽  
Scanning Calorimetry ◽  
Intrinsic Dissolution ◽  
X Ray ◽  
Ft Ir ◽  
Scanning Electron

To improve the physicochemical properties of valnemulin (VLM), different solid forms formed by VLM and organic acids, including tartaric acid (TAR), fumaric acid (FUM), and oxalic acid (OXA), were successfully prepared and characterized by using differential scanning calorimetry (DSC), scanning electron microscope (SEM), X-ray powder diffraction (XRPD), and Fourier-transform infrared spectroscopy (FT-IR). The excess enthalpy Hex between VLM and other organic acids was calculated by COSMOthermX software and was used to evaluate the probability of forming multi-component solids between VLM and organic acids. By thermal analysis, it was confirmed that multi-component solid forms of VLM were thermodynamically more stable than VLM itself. Through dynamic vapor sorption (DVS) experiments, it was found that three multi-component solid forms of VLM had lower hygroscopicity than VLM itself. Furthermore, the intrinsic dissolution rate of VLM and its multi-component forms was determined in one kind of acidic aqueous medium by using UV-vis spectrometry. It was found that the three multi-component solid forms of VLM dissolved faster than VLM itself.

scholarly journals COMPARISON STUDY OF GRINDING AND SLURRY METHOD ON PHYSICOCHEMICAL CHARACTERISTIC OF ACYCLOVIR – SUCCINIC ACID COCRYSTAL

2017 ◽  
Vol 10 (3) ◽  
pp. 153
Author(s):  
Fauzi Rahman ◽  
Agnes Nuniek Winantari ◽  
Dwi Setyawan ◽  
Siswandono .
Keyword(s):  
Fourier Transform ◽  
Ir Spectroscopy ◽  
Succinic Acid ◽  
Physicochemical Characteristic ◽  
Fourier Transform Infrared ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Slurry Method ◽  
Dissolution Efficiency

ABSTRACTObjective: This study aimed to compare the characteristics of acyclovir (ACV)-succinic acid (SA) cocrystal with grinding and slurry method.Methods: Cocrystals were prepared using grinding and slurry methods. Physicochemical characterizations were performed using powder X-raydiffraction (PXRD), differential scanning calorimetry, Fourier transform infrared (IR) spectroscopy, scanning electron microscope (SEM), anddissolution test.Results: The study revealed that cocrystal of ACV-SA showed a decrease in the melting temperature, i.e., 175.10°C, respectively, in comparison with themelting point of the constituent materials (ACV 253.53°C and SA 187.29°C). PXRD diffractogram showed that cocrystal with grinding method exhibitednew diffraction peaks at angle 2θ=8.92°, 16.24°, and 17.14°, while PXRD diffractogram of cocrystal with slurry method exhibit new diffraction peaksat angle 2θ=16.25°, and 19.63°. Characterization with IR spectroscopy showed the disappearance of transmission peaks at 3441cm disappearance ofC=O stretch at 1584cm and 1612cm. Dissolution efficiency of each treatment group calculated the efficiency of dissolution in 15th minutes, grindingmethod cocrystal with grinding time 15 minutes give the dissolution efficiency were 54.23%. Slurry method cocrystal with solvent concentration12 ml/g gives the high value of the dissolution efficiency is 74.36%. SEM micrographs showed that cocrystals prepared by solvent evaporation methodhave differences crystal form at magnification 5000× magnification compared to pure ACV and physical mixture.Conclusion: The study concluded that cocrystals of ACV-SA were successfully formed using grinding and slurry methods. The formed cocrystalsof ACV-SA exhibited different physicochemical characteristics as compared to the constituent materials. The formed cocrystals prepared by slurrymethod have a high intensity of diffraction peak on X-ray diffraction and highest dissolution efficiency at 15 minutes rather than grinding methodcocrystal.Keywords: Cocrystal, Acyclovir, Succinic acid, Grinding, Slurry, Powder X-ray diffraction, Fourier transform infrared, Dissolution rate. 

A New Modifier Prepared and it’s Applied in High-Density Polyethylene/Anhydrite Composites

2011 ◽  
Vol 415-417 ◽  
pp. 390-394
Author(s):  
Shao Hui Wang
Keyword(s):  
High Density Polyethylene ◽  
Bending Strength ◽  
Crystallization Rate ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Powder Particles ◽  
Ft Ir ◽  
Anchoring Group ◽  
The Impact

A new Modifier with Silicon radicals as anchoring group and poly(butyl acrylate) as solvatable chain was synthesized and its effect on the properties of HDPE/Anhydrite composites was investigated in this paper. Fourier transmission infrared spectroscopy (FT-IR) results show that the modifier react on the Anhydrite powder particles surface and the modified Anhydrite powder particles particles. compared with that of HDPE/Anhydrite (filled with same non-modified fraction), The impact strength, tensile strength, bending strength and Young’s modulus of modified HDPE/Anhydrite composites increased about 36.6%, 7.5%, 15.6% and 34% respectively. Based on surface analysis by scanning electron microscope (SEM), the Anhydrite powder particles buried well in HDPE matrix when Anhydrite powder particles was coated with the YB modifier. It was found that Anhydrite powder particles significantly increased the crystallization temperature and crystallization rate of HDPE by differential scanning calorimetry (DSC). At same time, through the X-ray diffraction (XRD) found the addition of the YB modifier modified Anhydrite powder particles can not change the formation of crystal HDPE, but can reduce the crystallite size.

scholarly journals Impact of heating temperatures on the properties of instant cassava flour

2021 ◽  
Vol 39 (No. 5) ◽  
pp. 360-367
Author(s):  
Achmat Sarifudin ◽  
Enny Sholichah ◽  
Woro Setiaboma ◽  
Nok Afifah ◽  
Dewi Desnilasari ◽  
...  
Keyword(s):  
Heating Temperature ◽  
Ethanol Solution ◽  
Starch Granules ◽  
Dsc Analysis ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Cassava Flour ◽  
X Ray ◽  
The Matrix ◽  
The Impact

Native cassava flour can be modified to be instant flour by heating the cassava flour in ethanol solution. The impact of heating temperatures of 60, 80, and 100 °C (coded as ICF-60, ICF-80, and ICF-100) on the properties of instant cassava flour (ICF), including colour, morphological, and thermal properties, water absorption, and solubility indexes and pasting behaviour, were investigated. Results showed that ICF produced at higher temperatures exhibited lower lightness, higher redness, and yellowness values. ICF-60 and ICF-80 still displayed the granular forms and birefringence properties of native starches, while granules of ICF-100 were broken and partially lost their birefringence properties. Results of X-ray diffraction (XRD) technique and differential scanning calorimetry (DSC) analysis suggested that the amylopectin double helixes of crystalline regions within the structure of ICF orientated to more perfect conformation before they were disrupted at the highest heating temperature (100 °C). During hydration, the starch granules of ICF-60 and ICF-80 absorbed water into their granules; meanwhile, ICF-100 entrapped water within the matrix formed by the entanglements of ICF-100 particles. Results of pasting behaviour analysis indicated that ICF-60 and ICF-80 showed better thermal stability while ICF-100 exhibited the highest cold viscosity.

scholarly journals CRYSTAL ENGINEERING OF QUERCETIN BY LIQUID ASSISTED GRINDING METHOD

2018 ◽  
Vol 81 (1) ◽  
Author(s):  
Umi Athiyah ◽  
Putu Andika Kusuma ◽  
Tutik Tutik ◽  
Maria L. A. D. Lestari ◽  
Dewi Isadiartuti ◽  
...  
Keyword(s):  
Ir Spectroscopy ◽  
Succinic Acid ◽  
Crystal Engineering ◽  
Crystal Habit ◽  
Dissolution Profile ◽  
X Ray ◽  
Pure Compounds ◽  
Ft Ir ◽  
The Impact ◽  
Ft Ir Spectroscopy

Quercetin has been proposed to exhibit numerous pharmacological benefits yet suffer low bioavailability due to the extremely low solubility. A research to study the impact of cocrystallization of quercetin with succinic acid on the solubility and dissolution profile has been performed. Cocrystallization in molar stoichiometry of 1:1 was carried out via liquid assisted grinding with methanol in ball milling apparatus. Cocrystal formation was identified by hot stage microscopy (HSM) at first, then cocrystal phase was characterized using differential thermal analysis (DTA), powder X-ray diffractometry (PXRD), scanning electron microscopy (SEM), and fourier-transform infrared (FT-IR) spectroscopy. Solubility and dissolution test were conducted as well. DSC thermogram exhibits new endothermic peak at 280.32°C representing the melting point of cocrystal phase alongside with endothermic point of pure compounds. Powder X-ray diffractograms show new diffraction peaks on behalf of cocrystal formation at 2θ=8.92, 9.88, 13.04, 29.78, 35.35°. FT-IR spectroscopy reveals band shifting in –OH group region. On SEM photographs, one can observe crystal habit of succinic acid being covered by crystal with different habit. This indicates that quercetin interacts with succinic acid only on the surfaces and causes imperfect formation of cocrystal phase. Cocrystallization quercetin improves solubility by 1.62 times higher and dissolution rate by 1.25 higher than pure quercetin (one-way ANOVA, p < 0.05).

X-ray computed microtomography to predict CO2 emissions in casts of 6 earthworm species (Lumbricidae)

2020 ◽  
Author(s):  
Guillaume Le Mer ◽  
Nicolas Bottinelli ◽  
Marie-France Dignac ◽  
Arnaud Mazurier ◽  
Laurent Caner ◽  
...  
Keyword(s):  
Organic Matter ◽  
Physicochemical Properties ◽  
Plant Litter ◽  
Ecological Groups ◽  
C Mineralization ◽  
Aporrectodea Caliginosa ◽  
Soil Macrofauna ◽  
X Ray ◽  
Earthworm Species ◽  
The Impact

&lt;p&gt;Plant residues are the main precursors of soil organic matter (SOM) and soil macrofauna is an important driver of ecological processes involved in the sequestration of carbon (C) in soils. In particular, earthworms are one of the largest contributors to soil matter formation in most terrestrial ecosystems. In the short term, they may increase the rate of OM turnover by mineralization, fragmentation and stimulation of microbial activity. On the other hand they may reduce OM degradability by forming stable aggregates and organo-mineral complexes protecting C from mineralization for longer time scales. Earthworms are classified in three main ecological groups depending on their behaviors and on their morpho-functional traits. However, their intra- or inter- ecological group effect on C stabilization needs to be investigated.&lt;/p&gt;&lt;p&gt;In this study, we explored the impact of earthworm diversity (composed of several species belonging to different ecological groups) on the physicochemical properties of casts, related to CO&lt;sub&gt;2&lt;/sub&gt; emissions. We hypothesized that C mineralization in casts would be related to the ecological category.&lt;/p&gt;&lt;p&gt;We studied casts of 6 species (2 anecic species: Lumbricus terrestris &amp; Aporectodea nocturna, 2 endogeic species: Allolobophora icterica &amp; Aporrectodea caliginosa and 2 epigeic species: Lumbricus castaneus &amp; Eisenia fetida) produced in a silty subsoil with addition of plant litter. Casts were incubated for 140 days under similar laboratory conditions. We measured CO&lt;sub&gt;2&lt;/sub&gt; mineralization, pH, elemental composition and physical cast organization by X-ray microtomography (resolution of 9.49 &amp;#181;m voxel) at 7, 42, and 140 days.&lt;/p&gt;&lt;p&gt;Our results showed lower CO&lt;sub&gt;2&lt;/sub&gt; mineralization in aggregates produced without earthworms than all earthworm casts. In the beginning of the incubation casts showed similar CO&lt;sub&gt;2&lt;/sub&gt; emissions and specific physicochemical properties as OC content and pH. After 140 days, CO&lt;sub&gt;2&lt;/sub&gt; emissions were earthworm species specific with Aporectodea nocturna showing highest CO&lt;sub&gt;2&lt;/sub&gt; emissions, and Aporrectodea caliginosa the lowest values. Microtomographic analyses showed that this is due to an increase of cast porosity with increasing cast age coupled with a concurrent decrease particulate organic matter (POM) structures. Our first results seemed to suggest that earthworms belonging to the same ecological category influence similarly C mineralization through their impact on the cast organization.&lt;/p&gt;

Effect of Intercritical Quenching on Microstructure and Mechanical Properties of Oil Casing Steel N80

2013 ◽  
Vol 395-396 ◽  
pp. 279-283
Author(s):  
Min Huang ◽  
Yu Wang ◽  
Ya Ni Zhang ◽  
Yue Wei Xie ◽  
Shuo Feng Li
Keyword(s):  
Tensile Strength ◽  
High Strength ◽  
Optical Microscope ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Scanning Calorimetry ◽  
Cross Sectional ◽  
Study Results ◽  
The Impact ◽  
The Sacrifice

In order to improve the toughness of oil casing steel N80 without the sacrifice of its original high strength, an intercritical quenching treatment was conducted under the temperature determined by a differential scanning calorimetry (DSC) analysis. Effects of intercritical quenching on the microstructure of oil casing steel N80 were characterized by means of optical microscope (OM) and scanning electron microscope (SEM). Tensile strength, reduction of cross-sectional area and microhardness were measured to evaluate the mechanical property of oil casing steel N80 after intercritical quenching treatment. The study results show that the tensile strength and microhardness of intercritical quenched oil casing steel N80 consisting of ferrite (F) and martensite (M) is slightly lower than that of tempered oil casing steel N80 composing of sorbite (S), yet which is still higher than that of full annealled oil casing steel N80 composing of pearlite (P) and a little amount of ferrite (F). In particular, the reduction of cross-sectional area of oil casing steel N80 intercritical quenched at 740°C is higher than those of tempered and full annealled. Additionally, both dimple and cleavage can be found on the impact fracture surface of N80 steel after intercritical quenching at 740°C. The toughness of oil casing steel N80 can be obviously improved by the intercritical quenching treatment at 740°C due to the formation of ferrite (F).

scholarly journals Preparation, Spectroscopy, Physicochemical Properties and X-ray Structure Analysis of 3,4,5-TrimethoxyN(2-hydroxybenzylidene) aniline

2009 ◽  
Vol 6 (4) ◽  
pp. 1103-1108 ◽  
Author(s):  
Kodjo Charles Guillaume ◽  
Zabri Herve ◽  
Benie Anoubile ◽  
Estienne Jacques
Keyword(s):  
Ir Spectroscopy ◽  
Physicochemical Properties ◽  
Title Compound ◽  
Electronic Spectroscopy ◽  
Visible Spectroscopy ◽  
Compound A ◽  
X Ray ◽  
H Nmr ◽  
Uv Visible ◽  
Single Crystal Analysis

3,4,5-TrimethoxyN-(salicylidene) aniline was synthesized and characterized by IR spectroscopy,1H NMR and x-ray single crystal analysis. UV-visible spectroscopy was used for physicochemical tests. X-ray data reveals that the crystalline network cohesion of this compound is essentially assured by CH/pi type hydrogen bounds. It crystallized in the orthorhombic Pbcn space group. Electronic spectroscopy shows that the title compound doesn't present photochromic property but thermochromic one. Intermolecular interactions analysis confirms for this compound a thermochromic structural predisposition.

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