scholarly journals Improvement of Physicochemical and Solubility of Dipyridamole by Cocrystallization Technology

2021 ◽  
Vol 11 (1-s) ◽  
pp. 43-48
Author(s):  
Ashwini Gawade ◽  
Ashwin Kuchekar ◽  
Sanjay Boldhane ◽  
Akshay Baheti
Keyword(s):  
Molecular Docking ◽  
Physicochemical Properties ◽  
Molar Ratio ◽  
Dissolution Behavior ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Release Formulation ◽  
Docking Method ◽  
Ph Modifier ◽  
Neutral Conditions

The aim of this study was to develop a pH-independent release formulation of dipyridamole (DP) by the combined use of pH-modifier technology and cocrystal technology tartaric acid (TA) was selected as an appropriate pH-modifier in terms of improving physicochemical properties and dissolution behavior of DP under neutral conditions. Molecular docking method was used to identify the suitable conformer.  Upon optimization of the ratio of TA to DP (molar ratio of 1:1, 1:2 and 1:3) was prepared by a solvent assisted griding method. Scanning electron microscopy images revealed that formation of DP-TA co crystals supported by supported by powder X-ray diffraction and differential scanning calorimetry analyses. Spectroscopic analysis suggested that there might be inter-molecular interaction among DP and TA resulting in pH independent dissolution behavior of drug substance. The study confirmed the selection of proper coformer and exhibited enhanced physicochemical, solubility and stability of the Dipyridamole cocrystals. Hence, based upon results it revealed that cocrystallization helps in improving the physicochemical properties of the API. Keywords: Dipyridamole, Coformer, Molecular docking, Radar chart, solvent assisted griding, Cocrystals

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 DESIGN, FORMULATION, AND CHARACTERIZATION OF APREMILAST-SACCHARIN COCRYSTALS LOADED WITH TOPICAL GEL

2020 ◽  
pp. 60-67
Author(s):  
TEJASWINI MANE ◽  
MUKESH MOHITE
Keyword(s):  
Physicochemical Properties ◽  
Factorial Design ◽  
Hydroxypropyl Methylcellulose ◽  
Gelling Agent ◽  
In Vitro Dissolution ◽  
Molar Ratio ◽  
Scanning Calorimetry ◽  
Topical Gel ◽  
Solubility Study

Objective: Most of the drugs are relevant to BSC class II and class IV having solubility problems. Cocrystallization of drug with conformer is an immense approach used to explore the physicochemical properties of drug. The objective of the present work was to design formulate and evaluate the drug cocrystals of poorly soluble drug apremilast (APR) with saccharin. Methods: Cocrystals of APR were prepared using the solvent evaporation technique. The saturated solubility study and in vitro dissolution study of cocrystals were carried out. The prepared cocrystals were characterized by differential scanning calorimetry (DSC), X-ray diffraction (XRD), and Fourier-transform infrared (FTIR) spectroscopy. The topical gel of APR cocrystals was formulated optimized and evaluated using three-level factorial design. Results: The cocrystals of APR were prepared in 1:1 molar ratio with saccharin. APR cocrystals showed the improvement in solubility and dissolution as compared to pure APR. The formation of cocrystals was confirmed from change in endothermic peak of DSC and from shifting of FTIR spectra of cocrystals. Crystallinity of cocrystal was confirmed from XRD pattern and noteworthy change in 2θ values of the intense peak. The topical gel of APR cocrystals was formulated and optimized using three-level factorial design using Carbapol-940 and hydroxypropyl methylcellulose (HPMC) as a gelling agent. Conclusion: The cocrystals with altered physicochemical properties of APR were prepared with saccharin and formulated as a topical gel to overcome the problems related to oral administration.

scholarly journals Microstructure Evolution and Performance Improvement of Hypereutectic Al–Mg2Si Metallic Composite with Ca or Sb

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2714
Author(s):  
Min Zuo ◽  
Boda Ren ◽  
Zihan Xia ◽  
Wenwen Ma ◽  
Yidan Lv ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Nucleation Behavior ◽  
X Ray ◽  
Primary Mg2si ◽  
Before And After ◽  
And Performance ◽  
Hardness Values

In this article, the modification effects on Al–Mg2Si before and after heat treatment were investigated with Ca, Sb, and (Ca + Sb). In comparison with single Ca or Sb, the samples with composition modifiers (Ca + Sb) had the optimal microstructure. The sample with a molar ratio for Ca-to-Sb of 1:1 obtained relatively higher properties, for which the Brinell hardness values before and after heat treatment were remarkably increased by 31.74% and 28.93% in comparison with bare alloy. According to differential scanning calorimetry analysis (DSC), it was found that the nucleation behavior of the primary Mg2Si phase could be significantly improved by using chemical modifiers. Some white particles were found to be embedded in the center of Mg2Si phases, which were deduced to be Ca5Sb3 through X-ray diffraction (XRD) and field-emission scanning electron microscope (FESEM) analyses. Furthermore, Ca5Sb3 articles possess a rather low mismatch degree with Mg2Si particles based on Phase Transformation Crystallography Lab software (PTCLab) calculation, meaning that the efficient nucleation capability of Ca5Sb3 for Mg2Si particles could be estimated.

scholarly journals Alumina Extraction from Coal Fly Ash via Low-Temperature Potassium Bisulfate Calcination

Minerals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 585 ◽  
Author(s):  
Chunbin Guo ◽  
Jingjing Zou ◽  
Shuhua Ma ◽  
Jianlin Yang ◽  
Kehan Wang
Keyword(s):  
Fly Ash ◽  
Low Temperature ◽  
Extraction Efficiency ◽  
Coal Fly Ash ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Increasing Demand ◽  
Technology Effects ◽  
Best Fit

Owing to the depletion of bauxite and increasing demand for alumina, calcination methods for extracting alumina from coal fly ash (CFA) were developed. However, these methods have disadvantages such as the need for high temperatures and the emission of toxic gases. Hence, in this study, Al2O3 was extracted from CFA via low-temperature potassium bisulfate calcination technology. Effects of the potassium bisulfate amount, calcination temperature, and calcination time on the alumina extraction efficiency were investigated using X-ray diffraction, thermal gravimetry, scanning electron microscopy, differential scanning calorimetry, and energy-dispersive spectroscopy. It was found that this technique could recover alumina efficiently, and potassium bisulfate significantly contributed to the degradation of mullite and corundum phases. Al2O3 in CFA was converted into soluble K3Al(SO4)3. With a KHSO4/Al2O3 molar ratio of 7:1, calcining temperature of 230 °C, and calcining time of 3 h, the alumina extraction efficiency reached a maximum of 92.8%. The Avrami–Erofeev equation showed the best fit with the kinetic data for the low-temperature calcination of CFA with KHSO4. The activation energy was 28.36 kJ/mol.

scholarly journals Ultrasonic Pretreatment in Synthesis of Caprylic-Rich Structured Lipids by Lipase-Catalyzed Acidolysis of Corn Oil in Organic System and Its Physicochemical Properties

Foods ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 566 ◽  
Author(s):  
Chonghui Yue ◽  
Hongyan Ben ◽  
Junwen Wang ◽  
Tiantian Li ◽  
Guoping Yu
Keyword(s):  
Physicochemical Properties ◽  
Corn Oil ◽  
Structured Lipids ◽  
Optimum Conditions ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Organic System ◽  
Ultrasonic Pretreatment ◽  
Pretreatment Time ◽  
Chain Type

The current work was to evaluate the lipase-catalyzed acidolysis of corn oil with caprylic acid (CA) in organic system under bath ultrasonic pretreatment and to analyze the physicochemical properties of structured lipids (SLs). Under optimum conditions (Novozym 40086 lipase, 200 W ultrasound power, 10 min ultrasound pretreatment time, 12% dosage of lipase, Triacylglycerol (TAG)/Free fatty acids (FFA): 1/8, 40 °C for 6 h), a 45.55% CA incorporation was obtained (named SLs-U). The highest CA incorporation was 32.75% for conventional method at reaction time of 10 h (named SLs-N). The predominant TAG types of SLs were MLM (medium-, long- and medium-chain-type TAGs) and MLL (medium-, long- and long-chain-type TAGs). X-ray diffraction analysis revealed that both SLs-U and SLs-N present β form. Differential scanning calorimetry (DSC) analysis showed that both SLs-U and SLs-N show a lower melting and crystallization temperature than corn oil. This study suggested that bath ultrasonic pretreatment can accelerate lipase-catalyzed acidolysis synthesis of MLM structured lipids in an organic system, and two kinds of structured lipids show similar physicochemical properties.

Iron and Iron-oxide on Silica Nanocomposites Prepared by the Sol-gel Method

2002 ◽  
Vol 17 (3) ◽  
pp. 590-596 ◽  
Author(s):  
G. Ennas ◽  
M. F. Casula ◽  
G. Piccaluga ◽  
S. Solinas ◽  
M. P. Morales ◽  
...  
Keyword(s):  
Sol Gel ◽  
Silica Matrix ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Gel Method ◽  
Sol Gel Method ◽  
Silica Nanocomposites ◽  
Transmission Electron ◽  
Nanometric Particles

γ–Fe2O3/SiO2 and Fe/SiO2 nanocomposites, with a Fe/Si molar ratio of 0.25, were prepared by the sol-gel method starting from ethanolic solutions of tetraethoxysilane and iron (III) nitrate. After gelation the xerogels were oxidated or reduced. Samples were investigated by transmission electron microscopy, x-ray diffraction, differential scanning calorimetry, and thermogravimetry. Magnetic properties of the samples were investigated at room temperature (RT) and at 77 K. Nanometric particles supported in the silica matrix were obtained in all cases. Bigger particles (10 nm) were obtained in the case of Fe/SiO2 nanocomposites with respect to the γ–Fe2O3/SiO2 samples (5–8 nm). A slight effect of sol dilution on particle size was observed only in the case of γ–Fe2O3/SiO2 nanocomposites. A superparamagnetic behavior was shown at RT only by γ–Fe2O3/SiO2 nanocomposites. Iron-based composites exhibited coercivity values higher than 700 Oe at RT.

Reactive phase formation in sputter-deposited Ni/Al multilayer thin films

1997 ◽  
Vol 12 (1) ◽  
pp. 133-146 ◽  
Author(s):  
K. Barmak ◽  
C. Michaelsen ◽  
G. Lucadamo
Keyword(s):  
Phase Formation ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Nucleation Kinetics ◽  
Scanning Calorimetry ◽  
Calorimetric Analysis ◽  
Transmission Electron ◽  
Nial Phase ◽  
Magnetron Sputter ◽  
Sputter Deposited

We have investigated reactive phase formation in magnetron sputter-deposited NiyAl multilayer films with a 1 : 3 molar ratio and various periodicities, L, ranging from 320 nm down to a codeposited film with zero effective periodicity. The films were studied by x-ray diffraction, differential scanning calorimetry, electrical resistance measurements, and transmission electron microscopy. We find that Ni and Al have reacted during deposition to form the B2 NiAl phase and an amorphous phase. The formation of these phases substantially reduces the driving force for subsequent reactions and explains why nucleation kinetics become important for these reactions. Depending on the periodicity, these reactions result in the formation of NiAl3 or Ni2Al9 followed by NiAl3. Detailed calorimetric analysis reveals differences in the nucleation and growth behavior of NiAl3 compared with other studies.

Crystallization Kinetics of β-Spodumene/Cordierite-Based Glass-Ceramics

2016 ◽  
Vol 881 ◽  
pp. 83-88 ◽  
Author(s):  
Rafael Bianchini Nuernberg ◽  
Oscar Rubem Klegues Montedo
Keyword(s):  
Crystallization Kinetics ◽  
Glass Ceramics ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Kinetics Parameters ◽  
Crystalline Phases ◽  
Cordierite Glass ◽  
Thermal And Electrical Properties ◽  
Kinetics Of

This work aims to investigate the crystallization kinetics of β-spodumene/cordierite glass-ceramics. Thus, three glasses with compositions based predominantly on cordierite (C), β-spodumene (L) and in a molar ratio 1:1 of both phases (CL) were prepared. The kinetics parameters such as activation energy for crystallization (ranging from 160 to 358 kJ/mol) and Avrami exponent (ranging from 1.4 to 10.7) were determined by means of non-isothermal methods using differential scanning calorimetry (DSC). Additionally, the samples were crystalized according to DSC analyses and characterized by using x-ray diffraction (XRD). The main detected crystalline phases were β-spodumene to the glass L, cordierite to the glass C and β-quartz, mulite and spinel to the glass CL. Considering the thermal and electrical properties of these crystalline phases, these glass-ceramics have potential use for LTCC (Low Thermal Co-fired Ceramics) applications.

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.

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