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.

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.

Glibenclamide-Nicotinamide Cocrystals Synthesized by The Solvent Evaporation Method to Enhance Solubility and Dissolution Rate of Glibenclamide

2019 ◽  
Vol 9 (01) ◽  
pp. 21-26
Author(s):  
Arif Budiman ◽  
Ayu Apriliani ◽  
Tazyinul Qoriah ◽  
Sandra Megantara
Keyword(s):  
Solvent Evaporation ◽  
Physical Mixture ◽  
Dissolution Profile ◽  
Solvent Evaporation Method ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Evaporation Method ◽  
Dissolution Properties ◽  
Mixture Characterization

Purpose: To develop glibenclamide-nicotinamide cocrystals with the solvent evaporation method and evaluate their solubility and dissolution properties. Methods: Cocrystals of glibenclamide-nicotinamide (1:2) were prepared with the solvent evaporation method. The prediction of interactive cocrystals was observed using in silico method. The solubility and dissolution were performed as evaluation of cocrystals. The cocrystals also were characterized by differential scanning calorimetry (DSC), infrared spectrophotometry, and powder X-ray diffraction (PXRD). Result: The solubility and dissolution profile of glibenclamide-nicotinamide cocrystal (1:2) increased significantly compared to pure glibenclamide as well as its physical mixture. Characterization of cocrystal glibenclamide-nicotinamide (1:2) including infrared Fourier transform, DSC, and PXRD, indicated the formation of a new solid crystal phase differing from glibenclamide and nicotinamide. Conclusion: The confirmation of cocrystal glibenclamide-nicotinamide (1:2) indicated the formation of new solid crystalline phases that differ from pure glibenclamide and its physical mixture

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 EFFECT OF SELECTED POLYMERS ON DISSOLUTION AND STABILIZATION OF AMORPHOUS FORM OF MELOXICAM

2017 ◽  
Vol 9 (9) ◽  
pp. 33
Author(s):  
Rana Obaidat ◽  
Bashar Al-taani ◽  
Hanan Al-quraan
Keyword(s):  
Polyethylene Glycol ◽  
Solid Dispersions ◽  
Dissolution Profile ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Polyethylene Glycol 4000 ◽  
Amorphous Form ◽  
Molecular Weights ◽  
Low Solubility ◽  
Reproducible Manner

Objective: Meloxicam is classified as class II corresponding to its high permeability and low solubility (12μg/ml). This study aims to compare the effect of selected polymers on stabilization of amorphous form, and dissolution of meloxicam by preparation of different solid dispersions using selected polymers (chitosan oligomers, polyvinylpyrrolidone K30, and polyethylene glycols).Methods: These solid dispersions were prepared using two different methods; solvent evaporation method for the two molecular weights chitosan carriers (16 and 11KDa) and polyvinylpyrrolidone-K30 and melting method for the two different molecular weights polyethylene glycol (4000 and 6000). The physicochemical properties of solid dispersions were analyzed using differential scanning calorimetry, Fourier transform infra-red analysis, Powder X-ray diffraction, and scanning electron microscopy. Selected dispersions were then compared to two selected marketed drugs (Mobic® and Moven®).Results: Best dissolution rates were obtained for both polyvinylpyrrolidone-K30 and polyethylene glycol 6000, followed by chitosan 16 kDa, chitosan 11 kDa, and polyethylene glycol 4000. Increasing polymeric ratio increased dissolution rate except for chitosan. Precipitation of the drug as amorphous form occurred in chitosan and polyvinylpyrrolidone-K30 dispersions, while no change in crystallinity obtained for polyethylene glycol dispersions. Failure of polyvinylpyrrolidone-K30 in the maintenance of stability during storage time was observed while re-crystallization occurred in chitosan-based dispersions, which ends with preferences to polyethylene glycol dispersions. After comparing the release of selected dispersions with the two selected polymers; all dispersions got a higher release than that of the two marketed drugs release.Conclusion: The dissolution profile of meloxicam has been increased successfully in a reproducible manner.

EFFECT OF DRUG TO B-CYCLODEXTRIN RATIO AND METHOD OF COMPLEXATION IN THE DEVELOPMENT OF B-CYCLODEXTRIN INCLUSION COMPLEX OF OFLOXACIN

INDIAN DRUGS ◽  
2013 ◽  
Vol 50 (12) ◽  
pp. 34-40
Author(s):  
M Panchpuri ◽  
◽  
D Singh ◽  
A Semalty ◽  
M. Semalty
Keyword(s):  
Inclusion Complex ◽  
In Vitro Dissolution ◽  
Molar Ratio ◽  
Dissolution Profile ◽  
Scanning Calorimetry ◽  
Dissolution Study ◽  
Drug Content ◽  
Kneading Method ◽  
Made In

Ofloxacin, a second generation fluoroquinolone, shows poor aqueous solubility and dissolution profile. Thus, ofloxacin–β-cyclodextrin complexes were prepared to improve its dissolution by imparting an environment of improved hydrophilicity. Ofloxacin was complexed with β-cyclodextrin (in 1:1 and 1:2 molar ratio) by two different methods namely, solvent evaporation and kneading method. These inclusion complexes were evaluated for solubility, drug content, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), X ray powder diffraction (XRPD) and in vitro dissolution study. The highest drug content (35.45%) was found in complex made by kneading method (OK1:1) in 1:1 molar ratio. All the complexes OSE1:1, OSE1:2, OK1:1, OK1:2 were found to be showing rough and porous surface morphology in SEM. Solubility as well as the dissolution of the complexes was found to be improved. Complex prepared by kneading method in 1:1 molar ratio (OK1:1) showed a marked improvement in percent drug release (88.94%) than that of pure drug (54.22%) at the end of 1 hour in dissolution study. FTIR, DSC and XRPD data confirmed the formation of inclusion complex. It was concluded that the complex made in 1:1 molar ratio (irrespective of the method) showed better solubility and dissolution profile as compared to complex made in 1:2 molar ratio.

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 Compression-Induced Phase Transitions of Bicalutamide

Pharmaceutics ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 438 ◽  
Author(s):  
Joanna Szafraniec-Szczęsny ◽  
Agata Antosik-Rogóż ◽  
Justyna Knapik-Kowalczuk ◽  
Mateusz Kurek ◽  
Ewa Szefer ◽  
...  
Keyword(s):  
Solid Dispersions ◽  
Amorphous Solid ◽  
Active Pharmaceutical Ingredient ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Amorphous Solid Dispersions ◽  
X Ray ◽  
High Propensity ◽  
Poorly Soluble ◽  
Amorphous Drug

The formation of solid dispersions with the amorphous drug dispersed in the polymeric matrix improves the dissolution characteristics of poorly soluble drugs. Although they provide an improved absorption after oral administration, the recrystallization, which can occur upon absorption of moisture or during solidification and other formulation stages, serves as a major challenge. This work aims at understanding the amorphization-recrystallization changes of bicalutamide. Amorphous solid dispersions with poly(vinylpyrrolidone-co-vinyl acetate) (PVP/VA) were obtained by either ball milling or spray drying. The applied processes led to drug amorphization as confirmed using X-ray diffraction and differential scanning calorimetry. Due to a high propensity towards mechanical activation, the changes of the crystal structure of physical blends of active pharmaceutical ingredient (API) and polymer upon pressure were also examined. The compression led to drug amorphization or transition from form I to form II polymorph, depending on the composition and applied force. The formation of hydrogen bonds confirmed using infrared spectroscopy and high miscibility of drug and polymer determined using non-isothermal dielectric measurements contributed to the high stability of amorphous solid dispersions. They exhibited improved wettability and dissolution enhanced by 2.5- to 11-fold in comparison with the crystalline drug. The drug remained amorphous upon compression when the content of PVP/VA in solid dispersions exceeded 20% or 33%, in the case of spray-dried and milled systems, respectively.

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.

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