scholarly journals Fluconazole-tartaric acid co-crystal formation and its mechanical properties

2021 ◽  
pp. 116-122
Author(s):  
Fikri Alatas ◽  
Nia Suwartiningsih ◽  
Hestiary Ratih ◽  
Titta Hartyana Sutarna
Keyword(s):  
Mechanical Properties ◽  
Tartaric Acid ◽  
Crystal Morphology ◽  
Active Pharmaceutical Ingredient ◽  
Raw Material ◽  
Molar Ratio ◽  
Crystal Formation ◽  
Polarization Microscopy ◽  
Scanning Calorimetry ◽  
Pxrd Pattern

Introduction: The formation of co-crystal is widely studied to obtain more favourable physicochemical properties than the pure active pharmaceutical ingredient (API). The co-crystal formation between an anti-fungal drug, fluconazole (FLU), and tartaric acid (TAR) has been investigated and its impact on mechanical properties has also been studied. Methods: The co-crystal of FLU-TAR (1:1) molar ratio was prepared by ultrasound-assisted solution co-crystallization (USSC) method with ethanol as the solvent. Polarization microscopy was used to observe the crystal morphology. Meanwhile, powder X-ray diffraction (PXRD) and differential scanning calorimetry (DSC) methods were used to characterise the co-crystal formation. The mechanical properties of the co-crystal, such as flowability and tablet-ability, were compared with pure FLU. Results: Photomicroscopes revealed the unique crystal morphology of the USSC product was different from the two starting components. The typical PXRD pattern was shown by the USSC product, which indicated the formation of FLU-TAR co-crystal. In addition, the DSC thermogram revealed 169.2°C as the melting point of the FLU-TAR co-crystal, which is between the melting points of FLU and TAR. It indicates that FLU-TAR co-crystal has better flowability and tablet-ability than pure FLU. Conclusion: FLU-TAR co-crystal is one of the alternative solid forms for a raw material in pharmaceutical tablet preparation because it has better mechanical properties than pure fluconazole.

scholarly journals Clozapine-carboxylic acid plasticized co-amorphous dispersions: Preparation, characterization and solution stability evaluation

2015 ◽  
Vol 65 (2) ◽  
pp. 133-146 ◽  
Author(s):  
Ahmed Mahmoud Abdelhaleem Ali ◽  
Adel Ahmed Ali ◽  
Ibrahim Abdullah Maghrabi
Keyword(s):  
Carboxylic Acid ◽  
Tartaric Acid ◽  
Molar Ratio ◽  
Sublingual Administration ◽  
Solution Stability ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Great Chance ◽  
Amorphous Dispersions ◽  
Pass Metabolism

Abstract This study addressed the possibility of forming of co-amorphous systems between clozapine (CZ) and various carboxylic acid plasticizers (CAPs). The aim was to improve the solubility and oral bioavailability of clozapine. Co-amorphous dispersions were prepared using modified solvent evaporation methodology at drug/plasticizer stoichiometric ratios of 1:1, 1:1.5 and 1:2. Solid state characterization was performed using differential scanning calorimetry, X-ray diffraction and infra red spectroscopy. Highly soluble homogeneous co-amorphous dispersions were formed between clozapine and CAPs via hydrogen bonding. The co-amorphous dispersions formed with tartaric acid (1:2) showed the highest dissolution percentage (> 95 % in 20 minutes) compared to pure crystalline CZ (56 %). Highly stable solutions were obtained from co-amorphous CZ-citric and CZ-tartaric acid at 1:1.5 molar ratio. The prepared dispersions suggest the possibility of peroral or sublingual administration of highly soluble clozapine at a reduced dose with the great chance to bypass the first pass metabolism.

scholarly journals Poly(Glycerol Succinate) as an Eco-Friendly Component of PLLA and PLCL Fibres towards Medical Applications

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1731
Author(s):  
Dorota Kolbuk ◽  
Oliwia Jeznach ◽  
Michał Wrzecionek ◽  
Agnieszka Gadomska-Gajadhur
Keyword(s):  
Mechanical Properties ◽  
In Vitro Study ◽  
Medical Applications ◽  
Crystal Formation ◽  
Scanning Calorimetry ◽  
Chain Mobility ◽  
X Ray Scattering ◽  
Crystallisation Behaviour ◽  
Main Component

This study was conducted as a first step in obtaining eco-friendly fibres for medical applications using a synthesised oligomer poly(glycerol succinate) (PGSu) as an additive for synthetic poly(L-lactic acid) (PLLA) and poly (L-lactide-co-caprolactone) (PLCL). The effects of the oligomer on the structure formation, morphology, crystallisation behaviour, and mechanical properties of electrospun bicomponent fibres were investigated. Nonwovens were investigated by means of scanning electron microscopy (SEM), wide angle X-ray scattering (WAXS), differential scanning calorimetry (DSC), and mechanical testing. The molecular structure of PLLA fibres is influenced by the presence of PGSu mainly acting as an enhancer of molecular orientation. In the case of semicrystalline PLCL, chain mobility was enhanced by the presence of PGSu molecules, and the crystallinity of bicomponent fibres increased in relation to that of pure PLCL. The mechanical properties of bicomponent fibres were influenced by the level of PGSu present and the extent of crystal formation of the main component. An in vitro study conducted using L929 cells confirmed the biocompatible character of all bicomponent fibres.

scholarly journals A comparison of mechanical properties and X-ray tomography analysis of different out-of-autoclave manufactured thermoplastic composites

2020 ◽  
Vol 39 (19-20) ◽  
pp. 703-720
Author(s):  
Diego Saenz-Castillo ◽  
María I Martín ◽  
Vanessa García-Martínez ◽  
Abhiram Ramesh ◽  
Mark Battley ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Raw Material ◽  
Thermoplastic Composites ◽  
Scanning Calorimetry ◽  
Consolidation Process ◽  
Plane Shear ◽  
X Ray ◽  
Void Distribution ◽  
Out Of Autoclave

Three different out-of-autoclave manufacturing processes of CF/poly-ether-ether-ketone thermoplastic composites were characterized, including innovative laser-assisted automated fibre placement with in situ consolidation. Characterization techniques included differential scanning calorimetry, ultrasonic non-destructive testing and matrix digestion, in addition to 3D X-ray microcomputed tomography to investigate the void distribution, size and shape. The results revealed that in situ consolidation process can lead to the accumulation of large voids between the upper layers. Interlaminar shear, in-plane shear, tensile and flexure testing were used for mechanical evaluation. A reduction in the mechanical properties was observed for in situ consolidation laminates when compared to the other out-of-autoclave methods. The drop in mechanical properties of in situ consolidation laminates was mainly attributed to the differences found in void distribution and size. Optimization of processing parameters along with higher quality prepreg raw material could be of assistance for the improvement of mechanical properties of in situ consolidation structures.

scholarly journals Physical Mixture Interaction of Acetaminophenol with Naringenin

2018 ◽  
Vol 18 (1) ◽  
pp. 18 ◽  
Author(s):  
Normyzatul Akmal Abd Malek ◽  
Hamizah Mohd Zaki ◽  
Mohammad Noor Jalil
Keyword(s):  
Interaction Strength ◽  
Active Pharmaceutical Ingredient ◽  
Binary Interaction ◽  
Molar Ratio ◽  
Attenuated Total Reflectance ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Mixture Ratio ◽  
X Ray ◽  
New Phase

The interaction of Active Pharmaceutical Ingredient (API) with other compounds will affect drugs stability, toxicity, modified dissolution profiles or may form a new compound with the different crystal structure. Acetaminophenol (APAP), the most common drug used widely (also known as Panadol) was mixed with Naringenin (NR) to glance for a new phase of interactions leading to new compound phase. The amide-acid supramolecular heterosynthon; N-H…O interaction between acid and the respective base were observed in the APAP-NR mixture blends. The interaction was prepared by the binary interaction from neat grinding and liquid-assisted grinding techniques at a different stoichiometry of binary mixture ratio of APAP-NR which were 1:1, 1:2 and 2:1 molar ratio. The interaction was estimated using Group Contribution Method (GCM) and physicochemical properties were characterized by Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR), powder X-ray diffraction (PXRD) and Differential Scanning Calorimetry (DSC) analysis. The GCM calculation gave good interaction strength at 212.93 MPa1/2. The ATR-FTIR, DSC and PXRD results obtained revealed an interaction with new phase formed.

scholarly journals Synthesis of Glibenclamide-Oxalic Acid Cocrystal using ThermalSolvent-Free Method

2020 ◽  
Vol 11 (03) ◽  
pp. 404-408
Author(s):  
Arif Budiman ◽  
Sandra Megantara ◽  
Rifaa’tush Sholihah ◽  
Saeful Amin
Keyword(s):  
Oxalic Acid ◽  
In Silico ◽  
Active Pharmaceutical Ingredient ◽  
Molar Ratio ◽  
Dissolution Profile ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Dissolution Tests ◽  
Ir Spectrophotometry ◽  
Crystalline Component

Solubility is an important parameter affecting the bioavailability of drugs. The solubility of an active pharmaceutical ingredient (API) could be improved through the formation of cocrystal, which is a crystalline complex composed of two or more different molecules. Glibenclamide (GCM) is an API with poor solubility in water, which belongs to class II, characterized as highly permeable with low solubility. Therefore, this study aimed to synthesize and characterize the cocrystal of GCM-oxalic acid (OA) using the melting method. The interaction between GCM-OA complexes was predicted using the in silico method. Also, the cocrystal complexes were characterized by differential scanning calorimetry (DSC), infrared (IR) spectrophotometry, and powder X-ray diffraction (PXRD), as well as, through solubility and dissolution tests. The result showed that GCM and OA have the potential of forming cocrystal through the in silico method. Also, the cocrystal of GCM-OA with a molar ratio 1:2, significantly improved the solubility and dissolution profile of GCM. In addition, the spectrum IR of cocrystal exhibited a shifting peak at 1,700 cm-1 indicating the presence of intermolecular interaction between GCM and OA. Furthermore, the DSC and PXRD analyses showed a new single endothermic peak and new diffraction peak pattern, respectively, indicating the formation of a new crystalline component.

Preparation and Properties of a Water-Swelling Rubber by in situ Formed Lithium Acrylate in Nitrile Rubber

2005 ◽  
Vol 13 (2) ◽  
pp. 181-190 ◽  
Author(s):  
Wentan Ren ◽  
Zonglin Peng ◽  
Yong Zhang ◽  
Yinxi Zhang
Keyword(s):  
Mechanical Properties ◽  
Bound Water ◽  
Free Water ◽  
High Water ◽  
Nitrile Rubber ◽  
Molar Ratio ◽  
Scanning Calorimetry ◽  
Swelling Properties ◽  
Water Swelling

Lithium acrylate (LiAA) was in situ prepared in nitrile rubber (NBR) through neutralization of lithium hydroxide (LiOH) and acrylic acid (AA) during mixing. The NBR/LiAA compounds were vulcanized with dicumyl peroxide (DCP). The in situ preparation and polymerization of LiAA were characterized using Fourier transform infrared (FTIR) spectrometer. The micrographs of the compounds and vulcanizates were explored using a scanning electron microscope (SEM). The effects of DCP and LiAA contents on the water-swelling and mechanical properties of the vulcanizates were studied. The relationship between the LiOH/AA molar ratio and the properties of the vulcanizates was investigated. The results showed that the in situ formed LiAA could improve the mechanical properties and water–swelling properties of the NBR/LiAA vulcanizates. The vulcanizates properly compounded had high water-swelling ratio over 800% and tensile strength more than 12MPa. The differential scanning calorimetry (DSC) measurements indicated that the water absorbed in the vulcanizate existed in PLiAA and NBR networks in three different physical states, namely, free water, freezable bound water and non-freezable bound water.

scholarly journals Effect of K/Al Molar Ratio on the Thermo-Mechanical Properties of Metakaolinite-Based Geopolymer Composites

Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3754
Author(s):  
Jan Kohout ◽  
Petr Koutník ◽  
Pavlína Hájková ◽  
Eliška Kohoutová ◽  
Aleš Soukup
Keyword(s):  
Mechanical Properties ◽  
Pore Size ◽  
Average Pore Size ◽  
Local Maximum ◽  
Raw Material ◽  
Molar Ratio ◽  
Average Pore ◽  
Thermal Dilatation ◽  
Compressive And Flexural Strengths ◽  
Geopolymer Composites

A metakaolinite-based geopolymer binder was prepared by using calcined claystone as the main raw material and potassium as the alkaline activator. Chamotte was added (65 vol%) to form geopolymer composites. Potassium hydroxide (KOH) was used to adjust the molar ratio of K/Al and the effect of K/Al on thermo-mechanical properties of geopolymer composites was investigated. This study aimed to analyze the effect of K/Al ratio and exposure to high temperatures (up to 1200 °C) on the compressive and flexural strengths, phase composition, pore size distribution, and thermal dilatation. With an increasing K/Al ratio, the crystallization temperature of the new phases (leucite and kalsilite) decreased. Increasing content of K/Al led to a decline in the onset temperature of the major shrinkage. The average pore size slightly increased with increasing K/Al ratio at laboratory temperature. Mechanical properties of geopolymer composites showed degradation with the increase of the K/Al ratio. The exception was the local maximum at a K/Al ratio equal to one. The results showed that the compressive strength decreases with increasing temperature. For thermal applications above 600 °C, it is better to use samples with lower K/Al ratios (0.55 or 0.70).

Effects of inorganic components on the mechanical properties of inorganic-organic hybrids synthesized from metal alkoxides and polydimethylsiloxane

1999 ◽  
Vol 14 (5) ◽  
pp. 1720-1726 ◽  
Author(s):  
Noriko Yamada ◽  
Ikuko Yoshinaga ◽  
Shingo Katayama
Keyword(s):  
Mechanical Properties ◽  
Differential Scanning Calorimetry ◽  
Network Structure ◽  
Molar Ratio ◽  
Metal Alkoxides ◽  
Inorganic Component ◽  
Scanning Calorimetry ◽  
Stress Strain ◽  
Dsc Measurements ◽  
Inorganic Components

Inorganic-organic hybrids (M–O–PDMS hybrids) have been synthesized from silanolterminated polydimethylsiloxane (PDMS) and inorganic sources of Al(O–sec–C4H9)3, Ti(OC2H5)4, and Ta(OC2H5)5. The molar ratio of M(OR)n/PDMS and the inorganic component derived from the different metal alkoxides were found to influence the structure and mechanical properties of the hybrids. Differential scanning calorimetry (DSC) measurements showed that the interaction between the inorganic component and PDMS increased in the order Al–O–PDMS < Ta–O–PDMS < Ti–O–PDMS hybrid. The stress-strain experiments revealed that the mechanical properties of the M–O–PDMS hybrids differed by the inorganic component, reflecting the network structure and strength of the interaction between the inorganic component and PDMS.

scholarly journals Thermal and Mechanical Assessment of PLA-SEBS and PLA-SEBS-CNT Biopolymer Blends for 3D Printing

2021 ◽  
Vol 11 (13) ◽  
pp. 6218
Author(s):  
Balázs Ádám ◽  
Zoltán Weltsch
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Mechanical Tests ◽  
The Other ◽  
Raw Material ◽  
Bending Test ◽  
Thermal And Mechanical Properties ◽  
Scanning Calorimetry ◽  
Partial Fracture ◽  
The Impact

Polylactic acid (PLA) is one of the most promising biopolymers often used as a raw material in 3D printing in many industrial areas. It has good mechanical properties, is characterized by high strength and stiffness, but unfortunately, it has some disadvantages; one is brittleness, and the other is slow crystallization. Amounts of 1–5% SEBS (styrene-ethylene-butylene-styrene) thermoplastic elastomer were blended into the PLA and the thermal and mechanical properties were investigated. DSC (Differential Scanning Calorimetry) measurements on the filaments have shown that SEBS increases the initial temperature of crystallization, thereby acting as a nucleating agent. The cooling rate of 3D printing, on the other hand, is too fast for PLA, so printed specimens behave almost amorphously. The presence of SEBS increases the impact strength, neck formation appears during the tensile test, and in the bending test, the mixture either suffers partial fracture or only bends without fracture. Samples containing 1% SEBS were selected for further analysis, mixed with 0.06 and 0.1% carbon nanotubes (CNTs), and tested for thermal and mechanical properties. As a result of CNTs, another peak appeared on the DSC curve in addition to the original single-peak crystallization, and the specimens previously completely broken in the mechanical tests suffered partial fractures, and the partially fractured pieces almost completely regained their original shape at the end of the test.

Spherical PF resin beads prepared from phenol-liquefied Bambusa dolichoclada with suspension polymerization

Holzforschung ◽  
2011 ◽  
Vol 65 (2) ◽  
Author(s):  
Wen-Jau Lee ◽  
Chao-Yun Yu ◽  
Kuo-Chun Chang ◽  
Ying-Pin Huang ◽  
Ching-Hui Chang ◽  
...  
Keyword(s):  
Phenol Formaldehyde ◽  
Suspension Polymerization ◽  
Raw Material ◽  
Molar Ratio ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Reaction Conditions ◽  
Free Phenol ◽  
Resin Beads ◽  
Dimensional Distribution

Abstract Bambusa dolichoclada Hayata (long-shoot bamboo) was liquefied in phenol with H2SO4 as a catalyst. The phenol-liquefied bamboo was then used as a raw material to prepare spherical phenol-formaldehyde (PF) resin beads by a suspension polymerization in a two-step process. The influence of the stirring speed (300, 350 and 400 rpm), the stabilizer dosage (3%, 4% and 5%) and the total molar ratio of formaldehyde to free phenol (F/P) (3.0/1, 3.5/1 and 4.0/1) on the properties of spherical PF beads was investigated. The results show that the yield, diameter and dimensional distribution of prepared PF beads were influenced by reaction conditions. The diameter of beads decreased as the stabilizer dosage increased. It had a more uniform dimensional distribution when stirred with a speed of 400 rpm. Differential scanning calorimetry analysis shows that PF beads obtained were not completely cured and the post-curing reaction took place at temperatures exceeded 150°C. As revealed by thermal gravimetric analysis, the char yield was over 60% after heating to 800°C.

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