Thermal Behaviour of Candesartan Active substance and in pharmaceutical compounds

2017 ◽  
Vol 68 (8) ◽  
pp. 1895-1902
Author(s):  
Ioana Cristina Tita ◽  
Eleonora Marian ◽  
Bogdan Tita ◽  
Claudia Crina Toma ◽  
Laura Vicas
Keyword(s):  
Thermal Behaviour ◽  
Active Substance ◽  
Pharmaceutical Research ◽  
Pharmaceutical Product ◽  
Nitrogen Atmosphere ◽  
Pure Substance ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Ft Ir

Thermal analysis is one of the most frequently used instrumental techniques in the pharmaceutical research, for the thermal characterization of different materials from solids to semi-solids, which are of pharmaceutical relevance. In this paper, simultaneous thermogravimetry/derivative thermogravimetry (TG/DTG) and differential scanning calorimetry (DSC) were used for characterization of the thermal behaviour of candesartan cilexetil � active substance (C-AS) under dynamic nitrogen atmosphere and nonisothermal conditions, in comparison with pharmaceutical product containing the corresponding active substance. It was observed that the commercial samples showed a different thermal profile than the standard sample, caused by the presence of excipients in the pharmaceutical product and to possible interaction of these with the active substance. The Fourier transformed infrared spectroscopy (FT-IR) and X-ray powder diffraction (XRPD) were used as complementary techniques adequately implement and assist in interpretation of the thermal results. The main conclusion of this comparative study was that the TG/DTG and DSC curves, together with the FT-IR spectra, respectively X-ray difractograms constitute believe data for the discrimination between the pure substance and pharmaceutical forms.

Thermal Behavoiur of Valsartan Active Substance and in Pharmaceutical Products

2017 ◽  
Vol 68 (10) ◽  
pp. 2307-2310
Author(s):  
Ioana Cristina Tita ◽  
Bogdan Tita ◽  
Claudia Crina Toma ◽  
Eleonora Marian ◽  
Laura Vicas
Keyword(s):  
Ir Spectra ◽  
Active Substance ◽  
Pharmaceutical Products ◽  
Nitrogen Atmosphere ◽  
X Ray ◽  
Analysis Phase ◽  
Ft Ir ◽  
Compounds Stability ◽  
Dsc Curves ◽  
Active Substances

G/DTG and DSC curves provide important information regarding the physical properties of the pharmaceutical compounds (stability, compatibility, polymorphism, kinetic analysis, phase transitions etc). The thermal behaviour of valsartan was studied under dynamic nitrogen atmosphere, in comparison with pharmaceutical products containing the corresponding active substances. Also, the FT�IR spectra and X-ray diffactogram of the same samples were recorded. The main conclusion of this comparative study was that TG / DTG and DSC assays along with FT-IR spectra and X-ray diffractograms provide credible data for differences between active substance and pharmaceutical forms.

Crystal structure, thermal behaviour and detonation characterization of bis(4,5-diamino-1,2,4-triazol-3-yl)methane monohydrate

2020 ◽  
Vol 76 (9) ◽  
pp. 891-896
Author(s):  
Biao Yan ◽  
Hongya Li ◽  
Haixia Ma ◽  
Xiangrong Ma ◽  
Zhiyong Sun ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Thermal Behaviour ◽  
Detonation Pressure ◽  
Amino Group ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Equivalent Equation ◽  
Experimental Density

Bis(4,5-diamino-1,2,4-triazol-3-yl)methane monohydrate (BDATZM·H2O or C5H10N10·H2O) was synthesized and its crystal structure characterized by single-crystal X-ray diffraction; it belongs to the space group P-1 (triclinic) with Z = 2. The structure of BDATZM·H2O can be described as a two-dimensional ladder plane with extensive hydrogen bonding and no disorder. The thermal behaviour was studied under non-isothermal conditions by differential scanning calorimetry (DSC) and thermogravimetric/differential thermogravimetric (TG/DTG) methods. The detonation velocity (D) and detonation pressure (P) of BDATZM were estimated using the nitrogen equivalent equation according to the experimental density. A comparison between BDATZM·H2O and bis(5-amino-1,2,4-triazol-3-yl)methane (BATZM) was made to determine the effect of the amino group; the results suggest that the amino group increases the hydrophilicity, space utilization and energy, and decreases the thermal stability and symmetry of the resulting compound.

scholarly journals ENHANCEMENT OF GLIBENCLAMIDE DISSOLUTION RATE BY SOLID DISPERSION METHOD USING HPMC AND PVP

2019 ◽  
pp. 19-24 ◽  
Author(s):  
ARIF BUDIMAN ◽  
IYAN SOPYAN ◽  
DENIA SEPTY RIYANDI
Keyword(s):  
Dissolution Rate ◽  
Solid Dispersion ◽  
Solid Dispersions ◽  
Hydroxypropyl Methylcellulose ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Rate Test ◽  
Ft Ir

Objective: The aim of this study was to investigate the effects of changing in the proportions of the solid dispersion formula on the dissolution rate of glibenclamide. Methods: Solid dispersions were prepared by solvent evaporation method by using methanol as solvent, hydroxypropyl methylcellulose (HPMC) and polyvinyl pyrrolidone (PVP) as polymers. The prepared product was evaluated by the saturated solubility test and the dissolution rate test. The prepared product was characterized by Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), and powder X-ray diffraction (PXRD) and Scanning Electron Microscopy (SEM). Results: The result showed solid dispersion with a ratio of glibenclamide: PVP: HPMC (1: 3: 6) has the highest increase in solubility (20 fold) compared to pure glibenclamide. This formula also showed an improvement in dissolution rate from 19.9±1.19% (pure glibenclamide) to 99±1.60% in 60 min. Characterization of FT-IR showed that no chemical reaction occurred in solid dispersion of glibenclamide. The results of X-ray diffraction analysis showed an amorphous form in all solid dispersion formulas. The results of DSC analysis showed that endothermic peak melting point of solid dispersion occurred, and the morphology of solid dispersion was more irregular than pure glibenclamide based on SEM characterization Conclusion: The solid dispersion of glibenclamide using PVP: HPMC as carriers can increase the solubility and dissolution rate compared to pure glibenclamide.

scholarly journals Study on the Miscibility of Polypyrrole and Polyaniline Polymer Blends

2018 ◽  
Vol 2018 ◽  
pp. 1-5 ◽  
Author(s):  
Tekalign A. Tikish ◽  
Ashok Kumar ◽  
Jung Yong Kim
Keyword(s):  
Differential Scanning Calorimetry ◽  
Polymer Blends ◽  
Processing Method ◽  
Phase Behaviour ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Amorphous Nature ◽  
Ft Ir

We report on the miscibility and phase behaviour of polypyrrole-polyaniline (PPy/PANI) as a function of blend composition. The PPy/PANI blends were prepared by solution processing method, using dimethyl sulfoxide (DMSO) solvent. Characterization of the polymer blends was carried out based on the data analysis from Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and differential scanning calorimetry (DSC). The PPy/PANI system was successfully formed blends in DMSO solvent. The polymer blends showed almost amorphous nature in XRD spectra because of intermolecular interaction between PPy and PANI macromolecules, which was confirmed by FT-IR data. Specifically, the DSC result for the PPY : PANI = 50 : 50 wt.% blend showed only one glass transition temperature (Tg), which indicates that the two polymers are well miscible without undergoing any phase separation.

Synthesis and Characterization of Novel Polymer of Vinyl Carbazole Bearing Thiophene Groups

2012 ◽  
Vol 562-564 ◽  
pp. 512-515
Author(s):  
Yun Xian Yang ◽  
Ji Ping Yang ◽  
Bing Zhou ◽  
Jing Yu Zhang
Keyword(s):  
Conjugated Polymer ◽  
Suzuki Reaction ◽  
Gel Permeation Chromatography ◽  
High Glass Transition Temperature ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Infrared Spectrometer ◽  
Ft Ir ◽  
Fluorescence Spectrometer

Combination of vinyl carbazole and thiophene groups’ excellent thermal properties and optical properties, a novel polymer named poly(2,7-bi-2-thienyl-9-vinyl-9-H-carbazole) was synthesized via radical polymerization and Suzuki reaction. The polymer was characterized using Fourier transform infrared spectrometer(FT-IR), gel permeation chromatography(GPC), differential scanning calorimetry(DSC), and X-Ray fluorescence spectrometer(XRF). It was found that this π-conjugated polymer containing vinyl carbazole and thiophene groups gave a high glass transition temperature (Tg=251°C). This feature made poly(2,7-bi-2-thienyl-9-vinyl-9-H-carbazole) possessing an excellent thermal performance.

scholarly journals Preparation and Characterization of Cetyl Trimethylammonium Intercalated Sericite

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Hao Ding ◽  
Yuebo Wang ◽  
Yu Liang ◽  
Faxiang Qin
Keyword(s):  
Ion Exchange ◽  
Interlayer Space ◽  
Xrd Analysis ◽  
Acid Activation ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

Intercalated sericite was prepared by intercalation of cetyl trimethylammonium bromide (CTAB) into activated sericite through ion exchange with the following two steps: the activation of sericite by thermal modification, acid activation and sodium modification; the ion exchange intercalation of CTA+into activated sericite. Effects of reaction time, reaction temperature, CTAB quantity, kinds of medium, and aqueous pH on the intercalation of activated sericite were examined by X-ray diffraction (XRD) analysis, Fourier transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The results indicated that the CTA+entered sericite interlayers and anchored in the aluminosilicate interlayers through strong electrostatic attraction. The arrangement of CTA+in sericite interlayers was that alkyl chain of CTA+mainly tilted at an angle about 60° (paraffin-type bilayer) and 38° (paraffin-type monolayer) with aluminosilicate layers. The largest interlayer space was enlarged from 0.9 nm to 5.2 nm. The intercalated sericite could be used as an excellent layer silicate to prepare clay-polymer nanocomposites.

Studies on the Preparation, Characterization and Solubility of -Cyclodextrin-Roxythromycin Inclusion Complexes

2009 ◽  
Vol 2 (2) ◽  
pp. 523-530
Author(s):  
D. Nagasamy Venkatesh ◽  
S. Karthick ◽  
M. Umesh ◽  
G. Vivek ◽  
R.M. Valliappan ◽  
...  
Keyword(s):  
Dissolution Rate ◽  
Inclusion Complexes ◽  
Phase Solubility ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Ir Studies ◽  
Poorly Soluble ◽  
Poorly Soluble Drug

Roxythromycin/ β-cyclodextrin (Roxy/ β-CD) dispersions were prepared with a view to study the influence of β-CD on the solubility and dissolution rate of this poorly soluble drug. Phase-solubility profile indicated that the solubility of roxythromycin was significantly increased in the presence of β-cyclodextrin and was classified as AL-type, indicating the 1:1 stoichiometric inclusion complexes. Physical characterization of the prepared systems was carried out by differential scanning calorimetry (DSC), X-ray diffraction studies (XRD) and IR studies. Solid state characterization of the drug β-CD binary system using XRD, FTIR and DSC revealed distinct loss of drug crystallinity in the formulation, ostensibly accounting for enhancement of dissolution rate.

Liquid crystalline polyureas with oligo(ethylene glycol) sequences

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Shahram Mehdipour-Ataei ◽  
Leila Akbarian-Feizi
Keyword(s):  
Liquid Crystalline ◽  
Spectroscopic Method ◽  
Polymerization Reaction ◽  
X Ray Diffraction ◽  
Subsequent Reaction ◽  
Scanning Calorimetry ◽  
Polar Solvents ◽  
X Ray ◽  
H Nmr ◽  
Ft Ir

AbstractA diamine monomer containing ester, amide and ether functional groups was prepared and its polymerization reaction with different diisocyanates to give main chain poly(ester amide ether urea)s was investigated. The monomer was synthesized via reaction of terephthaloyl chloride with 4-hydroxybenzoic acid and subsequent reaction of the resulted diacid with 1,8-diamino-3,6-dioxaoctane. The polymers were characterized by FT-IR and 1H-NMR spectroscopic method and elemental analysis. The resulting polymers exhibited excellent solubility in polar solvents. Crystallinity of the resulted polymers was evaluated by wide-angle X-ray diffraction (WXRD) method, and they exhibited semi-crystalline patterns. The glass transition temperatures (Tg) of the polymers determined by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) were in the range of 88-112 °C. The temperatures for 10% weight loss (T10) from their thermogravimetric analysis (TGA) curves were found to be in the range of 297-312 °C in air. Also the prepared polyureas showed liquid crystalline character.

One Step Synthesis and Characterization of Zirconia-Graphene Composites

2012 ◽  
Vol 600 ◽  
pp. 174-177 ◽  
Author(s):  
Jian Fei Xia ◽  
Zong Hua Wang ◽  
Yan Zhi Xia ◽  
Fei Fei Zhang ◽  
Fu Qiang Zhu ◽  
...  
Keyword(s):  
Synthesis And Characterization ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Graphene Composite ◽  
Transmission Electron ◽  
One Step ◽  
Ft Ir ◽  
Xrd Techniques

Zirconia-graphene composite (ZrO2-G) has been successfully synthesized via decomposition of ZrOCl2•6H2O in a water-isopropanol system with dispersed graphene oxide (GO) utilizing Na2S as a precursor could enable the occurrence of the deposition of Zr4+ and the deoxygenation of GO at the same time. Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) techniques were used to characterize the samples. It was found that graphene were fully coated with ZrO2, and the ZrO2 existing in tetragonal phase, which resulted in the formation of two-dimensional composite.

Synthesis and Properties of Thermotropic Liquid Crystalline Polyesters with Flexible Polymethylene Spacer

2010 ◽  
Vol 428-429 ◽  
pp. 126-131
Author(s):  
Wei Zhong Lu ◽  
Chun Wei ◽  
Qui Shan Gao
Keyword(s):  
Optical Microscopy ◽  
Liquid Crystalline ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Structure Morphology ◽  
Temperature Ranges ◽  
Ft Ir ◽  
Diffraction Peaks ◽  
Ubbelohde Viscometer

Polymethylene bis(p-hydroxybenzoates) were prepared from methyl p-hydroxybenzoate and different diols by melted transesterification reaction. Three liquid crystalline polyesters were synthesized from terephthaloyl dichloride and polymethylene bis(p-hydroxybenzoates). Its structure, morphology and properties were characterized by Ubbelohde viscometer, Fourier transform infrared spectroscopy (FT-IR), Differential scanning calorimetry (DSC), polarized optical microscopy (POM) with a hot stage, and wide-angle X-ray diffraction (WAXD). Results indicated that the intrinsic viscosities were between 0.088 and 0.210 dL/g. Optical microscopy showed that the TLCP has a highly threaded liquid crystalline texture and a high birefringent schlieren texture character of nematic phase and has wider mesophase temperature ranges for all polyesters. DSC analysis were found that the melting point (Tm), isotropic temperature (Ti) of TLCPs decreased and the temperature range of the liquid crystalline phase became wider with increased number of methylene spacers in the polyester. The WAXD results showed that TLCPs owned two strong diffraction peaks at 2θ near 19° and 23°.

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