scholarly journals Eutectic Formation of Naproxen with Some Dicarboxylic Acids

Pharmaceutics ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2081
Author(s):  
Dahye Kim ◽  
Soeun Jang ◽  
Il Won Kim
Keyword(s):  
Oral Delivery ◽  
Eutectic Mixture ◽  
Dicarboxylic Acids ◽  
Suberic Acid ◽  
Lamellar Structures ◽  
Eutectic Mixtures ◽  
System A ◽  
Eutectic Formation ◽  
Parameter Values ◽  
Biopharmaceutical Classification System

Eutectic formation with additives is one of the established methods to improve the dissolution behaviors of active pharmaceutic ingredients (APIs). The improvement is mainly due to the increase in the surface area for dissolution, which originates from the finely divided micro-domains generated through the phase separation of the miscible liquid components upon solidification. The present study is to identify eutectic-forming additives for naproxen (NPX), a class II API of the biopharmaceutical classification system. A particular aim was to develop a eutectic mixture with NPX at least over 20 wt%, a minimum to be practical for oral delivery. Screening based on the proximity of the solubility parameter values identified dicarboxylic acids (succinic acid, glutaric acid, and suberic acid) as desirable additives for NPX. Binary melting diagrams were constructed to confirm the eutectic compositions, and the eutectic mixture with suberic acid (NPX 55 wt%) was further investigated. The dissolution (at pH 5.0) of the melt crystallized eutectics was enhanced compared to the simple physical mixture of the same compositions and neat NPX, which was attributed to the microscopically observed lamellar structures. The current study should support the systematic investigations of API eutectic mixtures by selecting appropriate eutectic-forming additives.

scholarly journals Symbolic Encoding of Periodic Orbits and Chaos in the Rucklidge System

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Chengwei Dong ◽  
Lian Jia ◽  
Qi Jie ◽  
Hantao Li
Keyword(s):  
Periodic Orbits ◽  
Nonlinear Dynamical Systems ◽  
Unstable Periodic Orbits ◽  
Nonlinear Dynamical ◽  
System A ◽  
Return Maps ◽  
Phase Portrait Analysis ◽  
Encoding Method ◽  
First Return Maps ◽  
Parameter Values

To describe and analyze the unstable periodic orbits of the Rucklidge system, a so-called symbolic encoding method is introduced, which has been proven to be an efficient tool to explore the topological properties concealed in these periodic orbits. In this work, the unstable periodic orbits up to a certain topological length in the Rucklidge system are systematically investigated via a proposed variational method. The dynamics in the Rucklidge system are explored by using phase portrait analysis, Lyapunov exponents, and Poincaré first return maps. Symbolic encodings of the periodic orbits with two and four letters based on the trajectory topology in the phase space are implemented under two sets of parameter values. Meanwhile, the bifurcations of the periodic orbits are explored, significantly improving the understanding of the dynamics of the Rucklidge system. The multiple-letter symbolic encoding method could also be applicable to other nonlinear dynamical systems.

scholarly journals Hydrodynamically Balanced System: A Review

2021 ◽  
Vol 11 (1-s) ◽  
pp. 147-153
Author(s):  
Pawankumar H Yadav ◽  
Dipak P Kardile ◽  
Madhuri T Deshmukh ◽  
Rajkumar V. Shete
Keyword(s):  
Oral Delivery ◽  
Patient Adherence ◽  
Hollow Microsphere ◽  
Adhesive System ◽  
Evaluation Study ◽  
Gastric Residence Time ◽  
System A ◽  
Main Motive ◽  
Floating System

The most suitable drug delivery route is oral delivery due to its easily administration, patient adherence/ patient capacitance etc. Several approaches have been made for maximizing the G.R.T such as high-density system, floating system, swelling & expanding system and mucoadhesive & bio adhesive system etc. the main motive of reviewing the article is to focus on the mechanism of HBS system, classification with new system such as raft forming system and hollow microsphere, its application, marketed preparation and evaluation study. The procedure of gastric emptying is a complex and may leads to uncertainty for in vivo performance of the DDS. To prevent this type of complex formation and uncertainty, hard work has been done to expand the retention time of DDS for half of the day. The FDDS are beneficial in such process. Keywords: HBS system, GRDDS, gastric residence time (G.R.T), raft forming systems, floating formulations, evaluation study. 

Thermal Properties Analysis of Several N-Alkanes Eutectic Mixtures Applied in Building Envelopes

2012 ◽  
Vol 512-515 ◽  
pp. 3007-3010
Author(s):  
Jing Yu Huang ◽  
Shi Lei Lv ◽  
Chen Xi Zhang ◽  
Zhi Wei Wang
Keyword(s):  
Thermal Properties ◽  
Melting Temperature ◽  
Latent Heat ◽  
Heat Storage ◽  
Eutectic Mixture ◽  
Scanning Calorimetry ◽  
Latent Heat Storage ◽  
Building Envelopes ◽  
Eutectic Mixtures ◽  
Change Material

This study focuses on the preparation, thermal properties of alkanes eutectic mixtures (n-Octadecane/n-Eicosane, n-Octadecane/n-Docosane and n-Heptadecane /n-Eicosane) as candidate phase change material (PCM) for low temperature latent heat storage systems in building envelopes. Their melting temperature and latent heat were tested by Differential scanning calorimetry (DSC). The testing values were closed to calculation values of accepted theory that ensured the reliability of those datas. The results indicated n-Octadecane/n-Docosane eutectic mixture was more promising PCM for buildings in terms of melting temperature (25.3°C) and latent heat values of melting (158.2J/g).

Stability analysis of an electrically actuated microbeam using the Melnikov theorem and Poincaré mapping

2010 ◽  
Vol 225 (2) ◽  
pp. 488-497 ◽  
Author(s):  
M Zamanian ◽  
S E Khadem
Keyword(s):  
Phase Plane ◽  
Chaotic Behaviour ◽  
Damping Factor ◽  
Poincaré Mapping ◽  
System A ◽  
Poincare Mapping ◽  
Electrically Actuated ◽  
Electric Actuation ◽  
The Stability ◽  
Parameter Values

In this article, the stability of a microbeam under an electric actuation is studied. The electric actuation is induced by applying a voltage between the microbeam and an electrode plate that lies at the opposite side of the microbeam. In microswitches, the electric actuation is applied as a DC voltage, and in microresonators it is applied as a combination of AC—DC voltages. It is assumed that the midplane of the microbeam is stretched when it is deflected. It is also shown that by the altering DC electric actuation as a control parameter in a microswitch system, a stable and an unstable branches of equilibrium solution is observed, which meet each other at a saddle-node bifurcation point. The stability of a microresonator is studied using the phase plane diagram and Poincaré mapping. It is shown that depending on the value of damping factor, AC and DC electric voltages, and other parameters of the microresonator, a periodic solution, a quasi periodic, or a pull-in instability may be realized. The prediction of possible chaotic behaviour for microresonator is studied using the Melnikov theorem. It is shown that although for selected domain of system parameters the Melnikov function is satisfied for occurrence of chaotic behaviour, for theses parameter values the pull-in instability occurs before going into the chaotic behaviour. Briefly, the system does not realize any chaotic behaviour.

Properties modification by eutectic formation in mixtures of ionic liquids

RSC Advances ◽  
2015 ◽  
Vol 5 (28) ◽  
pp. 22178-22187 ◽  
Author(s):  
Olga Stolarska ◽  
Ana Soto ◽  
Héctor Rodríguez ◽  
Marcin Smiglak
Keyword(s):  
Surface Tension ◽  
Ionic Liquids ◽  
Physical Properties ◽  
Melting Temperature ◽  
Eutectic Mixtures ◽  
Eutectic Formation

The composition and temperature of three eutectic mixtures of ionic liquids and their physical properties (density, viscosity, and surface tension) are presented. Melting temperature depressions of up to ca. 50 K were found with regard to those of the parent ionic liquids.

Qualitative comparison of blackcurrant and blackcurrant—whey beverages

2011 ◽  
Vol 17 (4) ◽  
pp. 331-341 ◽  
Author(s):  
G. Jaworska ◽  
M. Sady ◽  
T. Grega ◽  
E. Bernaś ◽  
K. Pogoń
Keyword(s):  
Antioxidant Properties ◽  
Storage Period ◽  
Qualitative Comparison ◽  
System A ◽  
Flavor Analysis ◽  
Concentrate Acid ◽  
The Difference ◽  
Whey Beverages ◽  
Parameter Values

This study provides a qualitative comparison of blackcurrant and blackcurrant—whey beverages over a 12-month storage period. The amount of extract in the beverages was established as 12%, of which 25% was blackcurrant concentrate. Acid whey was used for the production of blackcurrant—whey beverages. In comparison to blackcurrant—whey beverages, blackcurrant beverages contained significantly more glucose, fructose, sucrose, polyphenols and vitamins C and B1. They also had a higher level of antioxidant activity against ABTS•+ and DPPH, with the difference ranging from 2% to 46%. On the other hand, blackcurrant—whey beverages contained more ash, proteins and vitamin B2 and the presence of lactose was detected. They were also characterized by higher color parameter values evaluated according to the CIE system. A general sensory evaluation awarded blackcurrant beverages with 0.5—1.3 more points than blackcurrant—whey beverages. A descriptive flavor analysis found that blackcurrant taste dominated in both types of beverages; however, in blackcurrant—whey beverages, the taste and smell of whey were also discernible. Changes in the quality of the beverages were observed during the storage period, notably a decrease in their antioxidant properties.

scholarly journals Simulation for determining the rod pump system parameter values using finite difference method

2021 ◽  
Vol 22 (1) ◽  
pp. 137
Author(s):  
Erwani Merry Sartika ◽  
Arief Darmawan
Keyword(s):  
Wave Equation ◽  
Finite Difference ◽  
Finite Difference Method ◽  
Difference Method ◽  
System Analysis ◽  
Tuning Parameter ◽  
Pump System ◽  
System A ◽  
Artificial Lift ◽  
Parameter Values

<p>Lifting <span>petroleum to the surface requires a mechanism called an artificial lift. This mechanism is useful for increasing the flow of fluids from a well. One that uses this method is the rod pump. The rod pump system needed the appropriate design (through the determination of the value of the parameters that affect) so that the pump runs optimally. But changing the appropriate design in real terms is not economically and time-efficient. The ideal rod pump system analysis procedure is to take downhole data (in the well) which is commonly called a pump card. A pump card calculation simulation is needed to efficiently analyze the rod pump system. The wave equation can describe the model of the rod pump system. A simulation of pump data calculation is performed using the finite difference method for the wave equation solution. Through the process of tuning parameter values using trial and error methods, the steps of tuning the parameter value of the rod pump system are proposed in this paper. For further research, a pump card calculation method based on a surface card can be developed to efficiently analyze the rod pump.</span></p>

Optimization of the Adsorber in an Adsorption Solar-Powered Cooling System

2005 ◽  
Author(s):  
Anne Ranes ◽  
Patrick Phelan ◽  
Rafael Pacheco ◽  
Anastasios Frantzis ◽  
Lionel Metchop
Keyword(s):  
Cooling System ◽  
Design Parameters ◽  
Adsorption System ◽  
Bed Porosity ◽  
System A ◽  
Solar Powered ◽  
Experimental Trials ◽  
The Cost ◽  
Fin Thickness ◽  
Parameter Values

The adsorption solar-powered cooling system is one of several types of solar-powered cooling systems currently under development. Increasing the efficiency and decreasing the cost of this system will make it a commercially viable alternative to traditional refrigeration systems. The objective of this project was to optimize the adsorber in the adsorption system. A mathematical model of the refrigerant distribution within a cylindrical adsorber was developed using equations from Chua et al. [1]. The simulation revealed effects of varying design parameters on the theoretical refrigerant mass flow rate, which is directly proportional to the system refrigeration capacity. These results indicated parameter values to be used in designing the adsorber. It was found that decreased particle radius, decreased bed porosity, increased pipe radius, increased adsorber radius, and increased fin thickness all positively affect the performance of the adsorption system. Further simulation and experimental trials are recommended to verify these results.

THERMODYNAMIC CALCULATION OF n-COMPONENT EUTECTIC MIXTURES

2004 ◽  
Vol 15 (05) ◽  
pp. 675-687 ◽  
Author(s):  
L. BRUNET ◽  
J. CAILLARD ◽  
P. ANDRÉ
Keyword(s):  
Organic Compound ◽  
Numerical Method ◽  
Melting Temperature ◽  
Nonlinear Problem ◽  
Thermodynamic Calculation ◽  
Eutectic Mixture ◽  
Organic Mixtures ◽  
Eutectic Mixtures ◽  
Newton Raphson ◽  
Raphson Method

This paper presents a simple numerical method to calculate the eutectic mixture composition and melting temperature. Using a Newton–Raphson method to solve the nonlinear problem, the calculation is possible for n-component eutectic. We tested this algorithm on inorganic and organic mixtures. A better correlation between experimental and numerical results has been found for organic compound.

scholarly journals Binary Mixtures of Some Active Pharmaceutical Ingredients with Fatty Alcohols—The Criteria of Successful Eutectic Formation and Dissolution Improvement

Pharmaceutics ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 1098
Author(s):  
Songhee Jin ◽  
Jisun Jang ◽  
Soyeon Lee ◽  
Il Won Kim
Keyword(s):  
In Vitro Release ◽  
Eutectic Mixture ◽  
Fatty Alcohols ◽  
Solubility Parameters ◽  
Active Pharmaceutical Ingredients ◽  
Pharmaceutical Ingredients ◽  
Eutectic Formation ◽  
Hoff Equation ◽  
Phase Behaviors

Pharmaceutical eutectics are solid mixtures, where the crystals of active pharmaceutical ingredients (APIs) are finely divided in the phase-separated microstructures. The size reduction makes the eutectic formation a viable option to improve the dissolution rate of the poorly soluble APIs. In the present study, ibuprofen, naproxen, and sorafenib were investigated in terms of their phase behaviors with fatty alcohols, such as tetradecanol, octadecanol, and docosanol. Among the studied APIs, only ibuprofen was able to form eutectics with the fatty alcohols, and this was in agreement with the feasibility prediction based on the van ’t Hoff equation and solubility parameters. In vitro release behavior was significantly improved for the ibuprofen/octadecanol eutectic mixture, although the practical insolubility of octadecanol in water was the opposite of the outstanding hydrophilicity of usual eutectic formers. The feasibility prediction and the choice of eutectic formers in the present study will be useful in advancing the utility of the pharmaceutical eutectics.

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