scholarly journals Development of a Method for the Quantification of Clotrimazole and Itraconazole and Study of Their Stability in a New Microemulsion for the Treatment of Sporotrichosis

Molecules ◽  
2019 ◽  
Vol 24 (12) ◽  
pp. 2333 ◽  
Author(s):  
Patricia Garcia Ferreira ◽  
Carolina Guimarães de Souza Lima ◽  
Letícia Lorena Noronha ◽  
Marcela Cristina de Moraes ◽  
Fernando de Carvalho da Silva ◽  
...  
Keyword(s):  
Benzyl Alcohol ◽  
Hplc Method ◽  
Stability Study ◽  
The Novel ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Sporothrix Brasiliensis ◽  
Accelerated Stability ◽  
New Association ◽  
Analytical Hplc

Sporotrichosis occurs worldwide and is caused by the fungus Sporothrix brasiliensis. This agent has a high zoonotic potential and is transmitted mainly by bites and scratches from infected felines. A new association between the drugs clotrimazole and itraconazole is shown to be effective against S. brasiliensis yeasts. This association was formulated as a microemulsion containing benzyl alcohol as oil, Tween® 60 and propylene glycol as surfactant and cosurfactant, respectively, and water. Initially, the compatibility between clotrimazole and itraconazole was studied using differential scanning calorimetry (DSC), thermogravimetric analysis (TG), Fourier transform infrared spectroscopy (FTIR), and X-ray powder diffraction (PXRD). Additionally, a simple and efficient analytical HPLC method was developed to simultaneously determine the concentration of clotrimazole and itraconazole in the novel microemulsion. The developed method proved to be efficient, robust, and reproducible for both components of the microemulsion. We also performed an accelerated stability study of this formulation, and the developed analytical method was applied to monitor the content of active ingredients. Interestingly, these investigations led to the detection of a known clotrimazole degradation product whose structure was confirmed using NMR and HRMS, as well as a possible interaction between itraconazole and benzyl alcohol.

Synthesis, characterization, and structures of zircona- and boracyclosiloxanes with ferrocenyl substituents

2002 ◽  
Vol 80 (11) ◽  
pp. 1469-1480 ◽  
Author(s):  
Karena Thieme ◽  
Sara C Bourke ◽  
Juan Zheng ◽  
Mark J MacLachlan ◽  
Fojan Zamanian ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Differential Scanning Calorimetry ◽  
Thermogravimetric Analysis ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
The Novel ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Multinuclear Nmr Spectroscopy

The novel zirconatetraferrocenylcyclotrisiloxane Cp2Zr(OSiFc2)2O (6), dizirconatetraferrocenylcyclotetrasiloxane [Cp2Zr(OSiFc2)O]2 (7), boratetraferrocenylcyclotrisiloxane (C6H5)B(OSiFc2)2O (8), and diboratetraferrocenylcyclotetrasiloxane [(C6H5)B(OSiFc2)O]2 (9) with ferrocenyl (Fc = Fe(η-C5H4)(η-C5H5)) substituents at silicon have been prepared from the reactions of Cp2Zr(NMe2)2 and PhBCl2 with diferrocenylsilanediol Fc2Si(OH)2 (3) and tetraferrocenyldisiloxanediol [Fc2SiOH]2O (5). The compounds were characterized by mass spectrometry, elemental analysis, UV–vis, IR, Raman, and multinuclear NMR spectroscopy, as well as single crystal X-ray diffraction. Thermogravimetric analysis and differential scanning calorimetry investigation of 6–9 showed that the cycles decompose before they can undergo any thermal ring-opening polymerization. In addition, no polymerization was detected in the presence of either KOSiMe3 or HOTf. The bulky ferrocenyl substituents on the Si atoms are likely to be at least partially responsible for the inability of these heterocycles to undergo ring-opening polymerization. Key words: heterocyclosiloxanes, ferrocenyl.

scholarly journals Puerarin dry powder inhaler formulations for pulmonary delivery: Development and characterization

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0249683
Author(s):  
Md Abdur Rashid ◽  
Saiqa Muneer ◽  
Tony Wang ◽  
Yahya Alhamhoom ◽  
Llew Rintoul ◽  
...  
Keyword(s):  
Low Dose ◽  
Structural Integrity ◽  
Dry Powder Inhaler ◽  
Pulmonary Delivery ◽  
Magnesium Stearate ◽  
Hplc Method ◽  
Dry Powder ◽  
Scanning Calorimetry ◽  
X Ray

This study aims at developing and characterizing the puerarin dry powder inhaler (DPI) formulations for pulmonary delivery. The inhalable particles size (<2 μm) was accomplished by micronization and its morphology was examined by scanning electron microscopy (SEM). The puerarin-excipient interaction in powder mixtures was analyzed by using Fourier transform infrared spectroscopy (FTIR), Raman confocal microscopy, X-Ray powder Diffraction (XRD), and differential scanning calorimetry (DSC) methods. Using a Twin stage impinger (TSI), the in-vitro aerosolization of the powder formulations was carried out at a flow rate of 60 L/min and the drug was quantified by employing a validated HPLC method. No significant interactions between the drug and the excipients were observed in the powder formulations. The fine particle fraction (FPF) of the drug alone was 4.2% which has increased five to six-fold for the formulations with aerosolization enhancers. Formulation containing lactose as large carriers produced 32.7% FPF, which further increased with the addition of dispersibility enhancers, leucine and magnesium stearate (40.8% and 41.2%, respectively). The Raman and FTIR techniques are very useful tool for understanding structural integrity and stability of the puerarin in the powder formulations. The puerarin was found to be compatible with the excipients used and the developed DPI formulation may be considered as an efficient formulation for pulmonary delivery for the management of various diseases at a very low dose.

scholarly journals Enantiomeric Determination of Omeprazole and Esomeprazole by a Developed and Validated Chiral HPLC Method and Stability Studies by Microthermal Analysis

2018 ◽  
Vol 16 (2) ◽  
pp. 221-233
Author(s):  
Asma Rahman ◽  
Mohammad Rashedul Haque ◽  
Md Zakir Sultan ◽  
M Muhibur Rahman ◽  
Mohammad A Rashid
Keyword(s):  
High Sensitivity ◽  
The United States ◽  
Hplc Method ◽  
Stability Study ◽  
Chiral Hplc ◽  
Scanning Calorimetry ◽  
Average Percentage ◽  
Relative Standard ◽  
Physical And Chemical

A rapid, accurate, precise, stability indicating and enantioselective chiral HPLC method was developed and validated for the quantitative (S)- and (R)- omeprazole in omeprazole formulations along with determination of enantiomeric purity of (S)- omeprazole in esomeprazole formulations according to the guidelines of the United States of Pharmacopeia (USP) and International Conference on Harmonization (ICH). The chromatographic separation was achieved with n-hexane/ 2-propanol/ acetic acid/ triethylamine (100 : 20 : 0.2 : 0.1, v/v) at a flow rate of 1.2 ml/min on Chiralcel OD-H and detected at 300 nm. The method showed good linearity, high sensitivity with detection limit (LOD) of 0.71 and 1.16 μg/ml and quantitation limit (LOQ) of 2.16 and 3.51 μg/ml for (S)- and (R)- omeprazole, respectively. The average percentage of recovery was found to be 100.85% to 101.36% for (S)- and 99.81% to 101.62% for (R)- omeprazole. The average percentage of relative standard deviation (% RSD) for intra- and inter- day precision were found to be 0.05% and 0.19% for (S)- and 0.03% and 0.13% for (R)- omeprazole, respectively. Stability study was performed under stress conditions. Microthermal analysis of omeprazole was also performed by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM) to assess the physical and chemical behavior of the drug. The method was successfully applied to the quantitation of (S)- and (R)- omeprazole for omeprazole and as well as determination of (S)- omeprazole purity for esomeprazole formulations.Dhaka Univ. J. Pharm. Sci. 16(2): 221-233, 2017 (December)

scholarly journals Optimization of Aceclofenac Proniosomes by Using Different Carriers, Part 1: Development and Characterization

Pharmaceutics ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 350 ◽  
Author(s):  
Rana Sammour ◽  
Muhammad Taher ◽  
Bappaditya Chatterjee ◽  
Aliasgar Shahiwala ◽  
Syed Mahmood
Keyword(s):  
Physical State ◽  
Water Solubility ◽  
Medical Model ◽  
Hplc Method ◽  
Ftir Analysis ◽  
Dsc Analysis ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Slurry Method ◽  
Model World

In the contemporary medical model world, the proniosomal system has been serving as a new drug delivery system that is considered to significantly enhance the bioavailability of drugs with low water solubility. The application of this system can improve the bioavailability of aceclofenac that is used for the relief of pain and inflammation in osteoarthritis, rheumatoid arthritis, and ankylosing spondylitis. The present study is intended to develop an optimized proniosomal aceclofenac formula by the use of different carriers. Aceclofenac proniosomes have been prepared by slurry method, and different carriers such as maltodextrin, mannitol, and glucose were tried. Prepared proniosomes characterized by differential scanning calorimetry (DSC) analysis and Fourier transform infrared (FTIR) analysis revealed the compatibility of the drug chosen with the ingredient added, powder X-ray diffractometry (XRD) confirmed the amorphous phase of the prepared proniosomes, and finally, the surfactant layer was observed by scanning electron microscopy (SEM). Aceclofenac physical state transformations were confirmed with all formulas but maltodextrin proniosomes exhibited solubility more than other formulations. HPLC method has been used to analyze the niosomes derived from proniosomes in terms of their entrapment capability and drug content. The obtained results revealed that aceclofenac proniosomes can be successfully prepared by using different carriers.

scholarly journals Continuous Manufacture and Scale-Up of Theophylline-Nicotinamide Cocrystals

Pharmaceutics ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 419
Author(s):  
Steven A. Ross ◽  
Andrew P. Hurt ◽  
Milan Antonijevic ◽  
Nicolaos Bouropoulos ◽  
Adam Ward ◽  
...  
Keyword(s):  
Scale Up ◽  
Physicochemical Characterization ◽  
Processing Parameters ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Accelerated Stability ◽  
Continuous Manufacture ◽  
Hot Melt

The aim of the study was the manufacturing and scale-up of theophylline-nicotinamide (THL-NIC) pharmaceutical cocrystals processed by hot-melt extrusion (HME). The barrel temperature profile, feed rate and screw speed were found to be the critical processing parameters with a residence time of approximately 47 s for the scaled-up batches. Physicochemical characterization using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and X-ray diffraction of bulk and extruded materials revealed the formation of high purity cocrystals (98.6%). The quality of THL-NIC remained unchanged under accelerated stability conditions.

scholarly journals Stability Study of Darunavir Ethanolate Tablets Applying a New Stability-Indicating HPLC Method

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Josilene Chaves Ruela Corrêa ◽  
Cristina Helena dos Reis Serra ◽  
Hérida Regina Nunes Salgado
Keyword(s):  
Degradation Products ◽  
Hplc Method ◽  
Stability Study ◽  
Raw Material ◽  
Forced Degradation ◽  
The Novel ◽  
Stability Indicating ◽  
Stability Indicating Method ◽  
The Stability ◽  
Darunavir Ethanolate

Chemical and physical degradation of drugs may result in altered therapeutic efficacy and even toxic effects. Therefore, the aim of this work was to study the stability of darunavir and to develop and validate a liquid chromatography (LC) method to determine darunavir in raw material and tablets in the presence of degradation products. The novel method showed to be linear from 6.0 to 21.0 μg/mL, with high precision (CV < 2%) and accuracy (recuperation of 99.64%). It is simple and reliable, free of placebo interferences. The robustness of the method was evaluated by a factorial design using seven different parameters. Forced degradation study was done under alkaline, acidic, and oxidative stress at ambient temperature and by heating. The LC method was able to quantify and separate darunavir and its degradation products. Darunavir showed to be unstable under alkaline, acid, and oxidative conditions. The novelty of this study is understanding the factors that affect darunavir ethanolate stability in tablets, which is the first step to unravel the path to know the degradation products. The novel stability-indicating method can be used to monitor the drug and the main degradation products in low concentrations in which there is linearity.

scholarly journals Enhancing the Solubility and Dissolution Performance of Safinamide Using Salts

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 989
Author(s):  
Lei Gao ◽  
Qian Liu ◽  
Xian-Rui Zhang
Keyword(s):  
Inhibition Activity ◽  
Type B ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Solubility In Water ◽  
X Ray ◽  
Mao B ◽  
Bcs Class Ii ◽  
Accelerated Stability ◽  
Biopharmaceutics Classification

Safinamide (SAF) is an anti-Parkinson’s disease (PD) drug that has selective monoamine oxidase type-B (MAO-B) inhibition activity. In 2017, SAF was approved by the U.S. Food and Drug Administration (FDA) as safinamide mesylate (SAF-MS, marketed as Xadago). Owing to its poor solubility in water, SAF is a Biopharmaceutics Classification System BCS Class II compound. In this study, four salts of safinamide (with hydrochloric acid (HCl), hydrobromic acid (HBr), and maleic acid (MA)) were obtained and characterized using single crystal X-ray diffraction (SCXRD), powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), and thermogravimetry (TG). The solubility and dissolution rate of all salts were systematically studied in water and phosphate buffer (pH 6.86) solutions. The accelerated stability tests indicated that all salts, except SAF-MA, had good stability under high humidity conditions.

Electron microscopy of crystalline structure in thermotropic random copolymers

1991 ◽  
Vol 49 ◽  
pp. 1054-1055
Author(s):  
Afzana Anwer ◽  
S. Eilidh Bedford ◽  
Richard J. Spontak ◽  
Alan H. Windle
Keyword(s):  
Electron Microscopy ◽  
Crystalline Structure ◽  
Liquid Crystalline ◽  
Elevated Temperatures ◽  
Random Copolymers ◽  
Molecular Characteristics ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Identical Monomer ◽  
Periodic Layer

Random copolyesters composed of wholly aromatic monomers such as p-oxybenzoate (B) and 2,6-oxynaphthoate (N) are known to exhibit liquid crystalline characteristics at elevated temperatures and over a broad composition range. Previous studies employing techniques such as X-ray diffractometry (XRD) and differential scanning calorimetry (DSC) have conclusively proven that these thermotropic copolymers can possess a significant crystalline fraction, depending on molecular characteristics and processing history, despite the fact that the copolymer chains possess random intramolecular sequencing. Consequently, the nature of the crystalline structure that develops when these materials are processed in their mesophases and subsequently annealed has recently received considerable attention. A model that has been consistent with all experimental observations involves the Non-Periodic Layer (NPL) crystallite, which occurs when identical monomer sequences enter into register between adjacent chains. The objective of this work is to employ electron microscopy to identify and characterize these crystallites.

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