scholarly journals A Contribution to the Solid State Forms of Bis(demethoxy)curcumin: Co-Crystal Screening and Characterization

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 720
Author(s):  
Steffi Wünsche ◽  
Lina Yuan ◽  
Andreas Seidel-Morgenstern ◽  
Heike Lorenz
Keyword(s):  
Aqueous Solubility ◽  
Melting Behavior ◽  
Water Mixture ◽  
Incongruent Melting ◽  
Active Components ◽  
Separation Processes ◽  
Equimolar Composition ◽  
Negative Effect ◽  
Crystallization From Solution ◽  
Crystallization From The Melt

Bis(demethoxy)curcumin (BDMC) is one of the main active components found in turmeric. Major drawbacks for its usage are its low aqueous solubility, and the challenging separation from other curcuminoids present in turmeric. Co-crystallization can be applied to alter the physicochemical properties of BDMC in a desired manner. A co-crystal screening of BDMC with four hydroxybenzenes was carried out using four different methods of co-crystal production: crystallization from solution by slow solvent evaporation (SSE), and rapid solvent removal (RSR), liquid-assisted grinding (LAG), and crystallization from the melt phase. Two co-crystal phases of BDMC were obtained with pyrogallol (PYR), and hydroxyquinol (HYQ). PYR-BDMC co-crystals can be obtained only from the melt, while HYQ-BDMC co-crystals could also be produced by LAG. Both co-crystals possess an equimolar composition and reveal an incongruent melting behavior. Infrared spectroscopy demonstrated the presence of BDMC in the diketo form in the PYR co-crystals, while it is in a more stable keto-enol form in the HYQ co-crystals. Solubility measurements in ethanol and an ethanol-water mixture revealed an increase of solubility in the latter, but a slightly negative effect on ethanol solubility. These results are useful for a prospective development of crystallization-based separation processes of chemical similar substances through co-crystallization.

The Melting Behavior of Poly(Ethylene Terephthalate)/ Attapulgite Nanocomposites

2013 ◽  
Vol 773 ◽  
pp. 530-533
Author(s):  
Chen Liu ◽  
Xiang Hui Lu ◽  
Xue Qi ◽  
Peng Li
Keyword(s):  
Crystallization Temperature ◽  
Isothermal Crystallization ◽  
Ethylene Terephthalate ◽  
Melting Process ◽  
Melting Behavior ◽  
Crystallization Time ◽  
Scanning Calorimetry ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene ◽  
Crystallization From The Melt

The melting and recrystallization behavior of Poly(ethylene terephthalate) (PET)/ Attapulgite(At)nanocomposites after isothermal crystallization from the melt was studied by Step-scan differential scanning calorimetry (SDSC). The influence of At contents, crystallization temperature and crystallization time on the melting process were examined. Two melting endotherms(in the SDSC CP.A curves, reversible part) and one recrystallization exotherm (in the SDSC CP.IsoK curves, irreversible part)of PET/At nanocomposites after isothermal crystallization were observed during the melt process. This ascribes to the melting-recrystallization mechanism .The low temperature endotherm attributes to the melting of primary crystal formed during the isothermal treating and the high temperature endotherm resulting from the melting of recrystallization materials. The reason why more recrystallization happened with the increase of At content was given and the process of recrystallization was described in detail. The effects of crystal perfection and recrystallization were minimized by increasing of crystallization temperature and time.

scholarly journals Rigorous modelling and optimization of hybrid separation processes based on pervaporation

2007 ◽  
Vol 5 (4) ◽  
pp. 1124-1147 ◽  
Author(s):  
Katalin Koczka ◽  
Peter Mizsey ◽  
Zsolt Fonyo
Keyword(s):  
Optimization Method ◽  
Systematic Investigation ◽  
Separation Process ◽  
Total Annual Cost ◽  
Water Mixture ◽  
Separation Processes ◽  
Distillation Columns ◽  
Membrane Technologies ◽  
Hybrid Separation Processes ◽  
Heteroazeotropic Distillation

AbstractHybrid separation processes are becoming more and more important in the practice if membrane technologies are also involved. In this work, a systematic investigation is completed for three sequence alternatives of distillation and pervaporation. These are the following: pervaporation followed with distillation (PV+D), distillation followed with pervaporation (D+PV), two distillation columns and a pervaporation unit between them (D+PV+D). The hybrid separation process alternatives are evaluated with rigorous modelling tools, but first, a rigorous simulation algorithm is determined for the pervaporation. The three hybrid separation processes are rigorously modelled with CHEMCAD, and optimized with the dynamic programming optimization method for the case of the separation of ethanol-water mixture. The objective function is the total annual cost (TAC). The energy consumption is also investigated. The selection of the ethanol-water mixture has two motivations: (i) it is quite often studied and well known, and (ii) to make biofuel (ethanol) production more economical, membrane technologies might also be applied. The results are compared with each other and with the classical separation completed with heteroazeotropic distillation. The optimized TAC shows that the distillation column followed with pervaporation is the most economical hybrid separation process alternative. Its TAC is about 66% of that of the classical separation.

scholarly journals Silymarin Loaded Novel Drug Delivery for Oral and Topical Administration

2020 ◽  
Vol 10 (3-s) ◽  
pp. 262-270
Author(s):  
Ankita Arun Gorhe ◽  
Abhijeet Kulkarni ◽  
Kandalkar Pallavi ◽  
Jagtap Snehal
Keyword(s):  
Drug Delivery ◽  
Drug Delivery System ◽  
Delivery System ◽  
Aqueous Solubility ◽  
Topical Administration ◽  
Route Of Administration ◽  
Pharmacological Properties ◽  
Active Components ◽  
Novel Drug Delivery System ◽  
Novel Drug

Silymarin is polyphenolic flavonoid obtained from the seeds of silybum marianum plant. It has various pharmacological properties such as hepatoprotective, anti-inflammatory, antioxidant, anti-carcinogenic, hypolipidemic properties. Silymarin has recently reported to be neuroprotective agent against neurodegenerative disease such as Alzheimer, Parkinson’s and cerebral ischemia. It contains eight active components, among which silibinin is the most active component. However, silymarin is BCS class II drug which having poor bioavailability due to extensive phase II metabolism, poor aqueous solubility, low permeability across intestinal epithelial cells and rapid excretion in bile and urine.  Therefore, it is necessary to understand all formulations and analytical aspects including all possible future prospects. In this review a potential approach to enhance solubility, bioavailability and to develop a robust formulation is studied. The number of studies describes novel drug delivery system (NDDS) based formulations have been significantly increased. The raise in novel drug delivery exploitation is essentially due to defeated barriers within technological process of lipid based nanoparticles formulations and increased knowledge of underlying mechanisms of transport of NDDS via different route of administration. This review focuses on pharmacological properties of silymarin, challenges, benefits and application of novel drug delivery system. To reduce the adverse effects and toxicities novel drug delivery will be an attractive approach of current therapies. Keywords: Silymarin, route of administration, novel drug delivery, bioavailability, solubility

Modeling the dynamic interaction between left ventricle and intra-aortic balloon pump

1991 ◽  
Vol 261 (4) ◽  
pp. H1300-H1311 ◽  
Author(s):  
Y. Sun
Keyword(s):  
Left Ventricle ◽  
Aortic Pressure ◽  
Assisted Circulation ◽  
Published Data ◽  
Active Components ◽  
State Equations ◽  
Intra Aortic Balloon Pump ◽  
Negative Effect ◽  
Flow Waveforms ◽  
Diastolic Augmentation

An analog model is developed to characterize how alterations of some intra-aortic balloon pump (IABP) parameters affect the coupling between left ventricle (LV) and aorta. The time-varying elastance concept is applied to modeling both active components (LV and IABP) in the assisted circulation. Pressure and flow waveforms in the system are determined by numerically integrating five simultaneous state equations that represent the system dynamics. Validity of the model is supported by good agreement between model predictions and published data on LV pressure-volume (P-V) loops, end-systolic P-V relations, and hemodynamic consequences of adjusting IABP timing and speed. The model also predicts that increasing balloon volume increases the diastolic aortic pressure augmentation but has a negative effect of increasing LV load. Increasing balloon diameter over length ratio and holding a constant volume increases the diastolic augmentation and decreases the LV demand. Positioning the balloon closer to the heart improves systolic unloading but affects neither diastolic augmentation nor cardiac output. These results suggest that occlusivity is a major determinant of IABP effectiveness and plays a more important role than balloon volume and position.

Preparation and Evaluation of Quercetin-Loaded MPEG-PLA Nanoparticles

2018 ◽  
Vol 14 (5) ◽  
pp. 366-376 ◽  
Author(s):  
Hiraku Onishi ◽  
Masashi Nakamura ◽  
Masanaho Sasatsu
Keyword(s):  
Organic Solvent ◽  
Therapeutic Potential ◽  
In Vitro Release ◽  
Aqueous Solubility ◽  
The Body ◽  
In Vivo Studies ◽  
Water Mixture ◽  
Biodistribution Studies

Background: Quercetin (QE) is one of the flavonoids with various biological functions such as anti-oxidation, anti-inflammatory and antitumor. However, the low aqueous solubility and short half-life in the body reduce its in vivo efficacy. Therefore, the appropriate delivery techniques to solve those problems have drawn much attention. In the present study, methoxypolyethylene glycol- poly-DL-lactic acid (MPEG-PLA) nanoparticles loaded with quercetin (QE), called NP, were prepared, and their antitumor characteristics were investigated in vitro and in vivo. Method: NPs were produced by evaporating organic solvent from the organic solvent-water mixture in four formulations. The particle characteristics and in vitro release were examined for the obtained preparations (NP1 – NP4). The antitumor features were investigated in vivo with different administration schedules using mice inoculated subcutaneously with murine Sarcoma 180. In addition, the efficacy of co-administration of NP with a strong antitumor chemotherapeutic agent, irinotecan hydrochloride (CPT-11), was examined. Biodistribution studies were performed using the same animal models. Result: The NP with the higher drug content (0.58 % (w/w)) and gradual release profile, Preparation NP4, were chosen and used as NP in the in vivo studies. NP suppressed tumor growth better than QE solution in various dosing schedules (total dose = 2 mg/kg). In the combination therapy with CPT-11, NP exhibited antitumor efficacy in a nearly additive manner. No decrease in body weight observed with any administration. NP markedly enhanced the systemic distribution and tumor localization. Conclusion: These results indicated that the present NP should promote the efficacy of QE, and might have useful therapeutic potential in the treatment of solid tumors.

scholarly journals Using Cocrystals To Systematically Modulate Aqueous Solubility and Melting Behavior of an Anticancer Drug

2009 ◽  
Vol 131 (47) ◽  
pp. 17048-17049 ◽  
Author(s):  
Christer B. Aakeröy ◽  
Safiyyah Forbes ◽  
John Desper
Keyword(s):  
Anticancer Drug ◽  
Aqueous Solubility ◽  
Melting Behavior

scholarly journals Thermal Performances and Fluidity of Biodegradable Poly(L-lactic acid) Filled with N, N'-Oxalyl Bis(piperonylic acid) Dihydrazide as a Nucleating Agent

2021 ◽  
Author(s):  
Lisha ZHAO ◽  
Yanhua CAI
Keyword(s):  
Lactic Acid ◽  
Temperature Region ◽  
Nucleating Agent ◽  
Melting Behavior ◽  
Decomposition Temperature ◽  
Melt Crystallization ◽  
Biodegradable Poly ◽  
Negative Effect ◽  
Infrared Spectrometer ◽  
Onset Decomposition Temperature

N, N'-oxalyl bis(piperonylic acid) dihydrazide (PAOD) was obtained through the amination of piperonylic acid chloride and its structure was characterized by Fourier transform infrared spectrometer and nuclear magnetic resonance. Melting blend technology was used to prepare the modified poly(L-lactic acid) (PLLA) containing the various loading PAOD as a new organic nucleating agent. The thermal performances including crystallization, melting behavior and thermal decomposition process, as well as the fluidity of PAOD-nucleated PLLA were investigated via a series of tests. The DSC results showed that, in comparison to DSC curve of the virgin PLLA, the DSC curves of all PLLA/PAOD appeared the sharp melt-crystallization peak, and a higher PAOD concentration caused the melt-crystallization to occur in the higher temperature region and reduced the negative effect of the high cooling rate on the melt-crystallization process. However, with increasing of PAOD concentration, the cold-crystallization enthalpy decreased from 24.4 J/g to 16.7 J/g. The melting peak after melt-crystallization depended on the heating rate and the PAOD concentration; and the double melting peaks appeared after isothermal crystallization in low temperature region was thought to be due to the melting-recrystallization. The addition of PAOD decreased the onset decomposition temperature of PLLA, but the onset decomposition temperature was determined by the PAOD concentration and the intermolecular interaction of PLLA and PAOD. Additionally, the PAOD could considerably improve the fluidity of PLLA.

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