• Title/Summary/Keyword: Formulation parameters

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Preparation and evaluation of proliposomes formulation for enhancing the oral bioavailability of ginsenosides

  • Duy-Thuc Nguyen;Min-Hwan Kim;Min-Jun Baek;Nae-Won Kang;Dae-Duk Kim
    • Journal of Ginseng Research
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    • v.48 no.4
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    • pp.417-424
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    • 2024
  • Background: This research main objective was to evaluate a proliposomes (PLs) formulation for the enhancement of oral bioavailability of ginsenosides, using ginsenoside Rg3 (Rg3) as a marker. Methods: A novel PLs formulation was prepared using a modified evaporation-on-matrix method. Soy phosphatidylcholine, Rg3-enriched extract, poloxamer 188 (Lutrol® F 68) and sorbitol were mixed and dissolved using a aqueous ethanolic solution, followed by the removal of ethanol and lyophilization. The characterization of Rg3-PLs formulations was performed by powder X-ray diffractometry (PXRD), transmission electron microscopy (TEM) and in vitro release. The enhancement of oral bioavailability was investigated and analyzed by noncompartmental parameters after oral administration of the formulations. Results: PXRD of Rg3-PLs indicated that Rg3 was transformed from crystalline into its amorphous form during the preparation process. The Rg3-encapsulated liposomes with vesicular-shaped morphology were generated after the reconstitution by gentle hand-shaking in water; they had a mean diameter of approximately 350 nm, a negative zeta potential (- 28.6 mV) and a high entrapment efficiency (97.3%). The results of the in vitro release study exhibited that significantly more amount of Rg3 was released from the PLs formulation in comparison with that from the suspension of Rg3-enriched extract (control group). The pharmacokinetic parameters after oral administration of PLs formulation in rats showed an approximately 11.8-fold increase in the bioavailability of Rg3, compared to that of the control group. Conclusion: The developed PLs formulation could be a favorable delivery system to improve the oral bioavailability of ginsenosides, including Rg3.

Sensitivity analysis for seismic response of a ship-block system

  • Kuchaksarai, Masoud Moghaddasi;Bargi, Khosrow
    • Structural Engineering and Mechanics
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    • v.23 no.3
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    • pp.309-323
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    • 2006
  • In this paper, seismic response of a free-standing ship located in a dry dock and supported by an arrangement of n keel blocks due to base excitation is addressed. Formulation of the problem including derivation of governing equations in various modes of motion as well as transition conditions from one mode to another is given in Moghaddasi and Bargi (2006) by same authors. On the base of numerical solution for presented formulation, several numbers of analyses are conducted to study sensitivity of system's responses to some major contributing parameters. These parameters include friction coefficients between contacting surfaces, block dimensions, peak ground acceleration, and the magnitude of vertical ground acceleration. Finally, performance of a system with usual parameters normally encountered in design is investigated.

Free vibration analysis Silicon nanowires surrounded by elastic matrix by nonlocal finite element method

  • Uzun, Busra;Civalek, Omer
    • Advances in nano research
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    • v.7 no.2
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    • pp.99-108
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    • 2019
  • Higher-order theories are very important to investigate the mechanical properties and behaviors of nanoscale structures. In this study, a free vibration behavior of SiNW resting on elastic foundation is investigated via Eringen's nonlocal elasticity theory. Silicon Nanowire (SiNW) is modeled as simply supported both ends and clamped-free Euler-Bernoulli beam. Pasternak two-parameter elastic foundation model is used as foundation. Finite element formulation is obtained nonlocal Euler-Bernoulli beam theory. First, shape function of the Euler-Bernoulli beam is gained and then Galerkin weighted residual method is applied to the governing equations to obtain the stiffness and mass matrices including the foundation parameters and small scale parameter. Frequency values of SiNW is examined according to foundation and small scale parameters and the results are given by tables and graphs. The effects of small scale parameter, boundary conditions, foundation parameters on frequencies are investigated.

Quality Control of Majoon-e-Nisyan and its Acute Oral Toxicity Study in Experimental Rats

  • Shaikh, Masud;Husain, Gulam M.;Naikodi, Mohammed Abdul Rasheed;Kazmi, Munawwar H.;Viquar, Uzma
    • CELLMED
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    • v.11 no.1
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    • pp.2.1-2.8
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    • 2021
  • The clinical condition Amnesia causes difficulty in learning new information and the inability to recall past events. It is primarily concerned with recent memory loss. Majoon-e-Nisyan (MJN) is a polyherbal Unani formulation, present in a semi-solid form. It is widely used potent drug of the Unani System of Medicine (USM) for treating Nisyan (amnesia). In the present study polyherbal Unani formulation, MJN has been studied for its quality control and acute toxicity. Standardization (quality control) of drugs deals with drug identity, drug quality and purity determination. Standardization of MJN had been done as per the Unani pharmacopoeial parameters approved by World Health Organization (WHO) - Pharmacognostical parameters, Physico-chemical parameters, high-performance thin-layer chromatography (HPTLC), microbial load, aflatoxin, and heavy metals. Solvents and chemicals used in the study were of analytical grade and used instrument were calibrated. By conducting an acute oral toxicity study in rats, the safety of MJN was assessed. The limit test method of OECD guideline 425 was followed in the study. Results of standardization and standard operating procedures (SOPs) for preparation of MJN may serve as the standard reference in the future. The data generated in the study for the quality control of MJN proved the quality of formulation and shows that MJN is not toxic in rats following acute dosing up to 2000 mg/kg bw. The data obtained in the paper for MJN may be used as a standard guideline for preparation of the formulation which can save time, cost, and resources for future research endeavours.

An empirical formulation to predict maximum deformation of blast wall under explosion

  • Kim, Do Kyun;Ng, William Chin Kuan;Hwang, Oeju
    • Structural Engineering and Mechanics
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    • v.68 no.2
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    • pp.237-245
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    • 2018
  • This study proposes an empirical formulation to predict the maximum deformation of offshore blast wall structure that is subjected to impact loading caused by hydrocarbon explosion. The blast wall model is assumed to be supported by a simply-supported boundary condition and corrugated panel is modelled. In total, 1,620 cases of LS-DYNA simulations were conducted to predict the maximum deformation of blast wall, and they were then used as input data for the development of the empirical formulation by regression analysis. Stainless steel was employed as materials and the strain rate effect was also taken into account. For the development of empirical formulation, a wide range of parametric studies were conducted by considering the main design parameters for corrugated panel, such as geometric properties (corrugation angle, breadth, height and thickness) and load profiles (peak pressure and time). In the case of the blast profile, idealised triangular shape is assumed. It is expected that the obtained empirical formulation will be useful for structural designers to predict maximum deformation of blast wall installed in offshore topside structures in the early design stage.

A Fuzzy Logic Controller Design Method using Characteristic Parameters (특성화 인자를 이용한 퍼지제어기의 설계방법에 관한 연구)

  • 김영선;조형석
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.197-197
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    • 2000
  • In this paper, we present a novel method for design of fuzzy Logic controllers by defining a set of characteristic parameters (CFLCS). These parameters are extracted and defined by examining the structure and characteristics of the individual components of FLCs and parameterizing those. Based upon this formulation, a series of simulations is conducted for plants having simple dynamics in order to see the performance of this proposed method. The simplicity and effectiveness of this method are discussed in detail.

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Analysis of Magnetically Coupled Wireless Power Transmission for Maximum Efficiency

  • Kim, Chung-Ju;Lee, Bom-Son
    • Journal of electromagnetic engineering and science
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    • v.11 no.3
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    • pp.156-160
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    • 2011
  • We have proposed and analyzed an equivalent circuit for a magnetically coupled wireless power transmission (WPT) system between two loop resonators by considering its coupling coefficient and radiation-related parameters. A complete formulation is provided for all the necessary circuit parameters. The mechanism of radiation loss is sufficiently explained. The circuit and electromagnetic (EM) simulation results have been shown to be in good agreement. Based on the proposed circuit formulation, a specific load impedance for maximum WPT efficiency was found to exist. The proposed modeling of the WPT in terms of circuit characterizations provides sufficient insight into the problems associated with WPT.

Viscous damping effects on the seismic elastic response of tunnels in three sites

  • Sun, Qiangqiang;Bo, Jingshan;Dias, Daniel
    • Geomechanics and Engineering
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    • v.18 no.6
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    • pp.639-650
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    • 2019
  • Time-domain commercial codes are widely used to evaluate the seismic behavior of tunnels. Those tools offer a good insight into the performance and the failure mechanism of tunnels under earthquake loading. Viscous damping is generally employed in the dynamic analysis to consider damping at very small strains in some cases, and the Rayleigh damping is commonly used one. Many procedures to obtain the damping parameters have been proposed but they are seldom discussed. This paper illustrates the influence of the Rayleigh damping formulation on the tunnel visco-elastic behavior under earthquake. Four Rayleigh damping determination procedures and three soil shear velocity profiles are accounted for. The results show significant differences in the free-field and in the tunnel response caused by different procedures. The difference is somewhat decreased when the soil site fundamental frequency is increased. The conventional method which consists of using solely the first soil natural mode to determine the viscous damping parameters may lead to an unsafe seismic design of the tunnel. In general, using five times site fundamental frequency to obtain the damping formulation can provide relatively conservative results.

OPTIMAL RESTRICTIONS ON REGRESSION PARAMETERS FOR LINEAR MIXTURE MODEL

  • Park, Sung-Hyun;Ahn, Jung-Yeon
    • Proceedings of the Korean Society for Quality Management Conference
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    • 1998.11a
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    • pp.239-250
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    • 1998
  • A method of finding optimal linear restriction on regression parameters in linear model for mixture experiments in the sense of minimizing integrated mean squared error is studied. We use the formulation of optimal restrictions on regression parameters for estimating responses proposed by Park(1981) by transforming mixture components to mathematically independent variables.

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Multiobjective Nonlinear Decision Making with Fuzzy Parameters and Fuzzy Equal Goals (퍼지모수들과 퍼지항등목표들을 가지는 다목적 비선형 의사결정)

  • 윤연근;남현우;이상완
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.20 no.41
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    • pp.41-50
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    • 1997
  • In this paper, we presents the method for finding the compensatory solution for fuzzy multiobjective nonlinear programming problem with fuzzy parameters involved in the problem-formulation process and fuzzy equal goals of the decision maker for each of the objective functions. The fuzzy parameters in the objective functions and the constraints characterized by fuzzy numbers. The proposed method can be applied to case with multiobjective problems and guarantee an efficient solution. An illustrative numerical example is presented.

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