Instant Formulation Research Articles

Formulation of inhalable beclomethasone dipropionate-mannitol composite particles through low-temperature supercritical assisted atomization

• Mannitol carrier and drug-mannitol composites were produced using LTSAA. • Fine corrugated surface of mannitol-leucine particles enhanced aerosol performance. • Aerosol performance of composite enhanced 3.4 times compared to as-received drug. • Drug release of composite was 15.6 times faster than that of as-received drug. • Drug-mannitol composites acted as instant formulation of inhalable dry powder. Mannitol carrier and drug-carrier composite particles were produced via low-temperature supercritical assisted atomization (LTSAA). The enhanced aerosolization of the mannitol carrier particles with added L -leucine could be attributed to the formation of fine corrugated particles, which reduced the interparticle cohesion and led to better flowability of the mannitol carrier particles. A poorly water-soluble drug, beclomethasone dipropionate (BDP), and mannitol co-precipitated during LTSAA with the optimal addition of 9.1 mass % L -leucine. The in vitro aerosolization and dissolution experiments indicated that the fine particles fraction ( FPF ) of the drug-carrier composite particles was 3.4 times ( FPF = 49.9 %) higher than that of the as-received BDP ( FPF = 14.7 %) and the 63.2 % drug release time of the drug-carrier composite particles was 15.6 times faster than that of as-received BDP. This study suggests that the drug-carrier composites produced using LTSAA can be employed in the instant formulation of inhalable dry powder.

Application of Pregelatinized Meal of Rice and Sorghum in the Preparation of Instant Soups: Centesimal Characterization, Technological, Microbiological and Sensory Quality

Due to the technological importance that the extrusion process represents in the application of fast food, the objective of this work was to apply pregelatinized rice and sorghum flours in the development of an instant preparation soup and to evaluate its centesimal, technological, and their sensorial analysis. Ten formulations of the instant soup were prepared from the mixtures experimental design. According to the experimental results, it can be stated that the predicted values corroborated with the experimental values, that is, a mixture was obtained for the instant soup with the characteristics of water absorption, water solubility, color, luminosity and viscosity close to the predicted by the models. After the physical and chemical analysis, the microbiological characterization of the best formulation defined by the desirability test was used, which demonstrated that the product is suitable to microbiological standards. The results obtained showed that the 80:10:10 instant soup formulation of pregelatinized rice flour, pregelatinized sorghum flour and potato starch allowed the experimental development of a new product with good nutritional characteristics benefits. It was obtained a food with good technological characteristics solubility and absorption in water, good viscosity, light color and with good sensory acceptance by the tasters.

Development of Instant Ox Tail Soup Supplemented with Mushroom and Moringa Leaves

Background: Food consumption has been changing during the past decade and need for instant formulation is being increased. The potential of growth of convenience foods in Kenya is vastly untapped.
 Objective: This study was to develop a dehydrated instant ox tail soup mix supplemented with mushroom and Moringa leaves and other vegetables to enhance its protein quality and reduce the difficulty in preparation of the soup inorder to minimize the problem of protein-energy malnutrition in Kenya.
 Methods: After destalking, washing was done. The whole leaves were boiled with 0.1% (v/v) sodium metabi-sulphite for 10 minutes.. The leaves were then spread out on the racks for 15 min. The leaves were then spread thinly on mesh and allowed to dry in the oven dryer for four 4 hours. The dried leaves were ground into powder and packaged in a plastic container and stored at room temperature. Fresh oyster mushrooms (Pleurotus ostearus (Jacq.) P. Kumm. were cleaned, chopped into small pieces of about 5-7 mm thickness, then pretreated by blanching in water at 60ºC for about 2 minutes, cooked and dried to a moisture content of 5-7%, then dried, sieved and stored in airtight containers. The oxtail was cut into small pieces and soaked in vinegar for 10 minutes this is because vinegar tends to kill salmonella, E coli and other gram-negative bacteria. It was then taken to an oven to dry it further at 70ºC for 48 hours, then ground and packed in airtight container at room temperatures. Tomatoes were cut into slices, cooked, cooled, and the pulp was dried in an oven drier for 3 hours at 60ºC. The dried pulp was ground and packaged in airtight glass containers. Proximate analysis was done according to AOAC methods (2005).
 Results: Proximate analysis were as follows: Oyster mushroom powder the fat, ash, protein, , moisture and total carbohydrates were as follows 2.5%, 8.1%, 31.5% 3, 73% and 40.8% respectively on dry weight basis. In the case of Moringa powder the fat, ash, protein, and total carbohydrate results were as follows: 6.3%, 9.5%, 33.4%, and 57.63%.
 Ox tail powder the results were as follows fat was 14.6%, ash 5.1%, protein 23.7%, total carbohydrates 36.2% and moisture content 4.72%.
 Conclusion: Instant oxtail soup supplemented with mushroom and Moringa Leaves can be developed using Oyster mushroom.

A fully-implicit solution for the single-pressure two-fluid model with sharp discontinuities

Abstract Transient two-phase flow in pipes is a common phenomenon in nuclear and petroleum engineering. Due to complex interactions at phase interfaces and the large variation on fluid properties, multiphase flows are much more complex than single-phase flows. However, modeling pressure, temperature, phase velocities and volumetric fractions is essential for design, management, optimization and safety analysis. Two approaches are generally applied for modeling multiphase flow: (a) local instant formulation and (b) averaged formulation. In this paper, the averaged Single-Pressure Two-Fluid model (together with Bestion’s correlation for interfacial pressure) is studied and a fully-implicit numerical solution is proposed. The obtained numerical solutions were compared to reference solutions for benchmark problems (water faucet tests and phase segregation) available in the literature. Aiming to verify if the aforementioned averaged model and the proposed fully-implicit solutions can be applied to study problems with counter-current flow and sharp discontinuities in pressure, velocities and volumetric fractions, new reference solutions for a generalized transient frictionless segregation test are proposed. Comparison between the proposed reference and numerical solutions allowed for a detailed verification of the studied averaged model. Finally, sudden multiphase fluid injection with subsequent tube closure was studied and the numerical results were discussed. As expected, it was observed transient surge pressure and co-current/counter-current flow with phase appearance and disappearance.

Extemporaneously preparative biodegradable injectable polymer systems exhibiting temperature-responsive irreversible gelation

On clinical application of biodegradable injectable polymer (IP) systems, quick extemporaneous preparation of IP formulations and longer duration time gel state after injection into the body are the important targets to be developed. Previously, we had reported temperature-responsive covalent gelation systems via bio-orthogonal thiol-ene reaction by ‘mixing strategy’ of amphiphilic biodegradable tri-block copolymer (tri-PCG) attaching acryloyl groups on both termini (tri-PCG-Acryl) with reactive polythiol. In other previous works, we found ‘freeze-dry with PEG/dispersion’ method as quick extemporaneous preparation method of biodegradable IP formulations. In this study, we applied this quick preparative method to the temperature-triggered covalent gelation system. The instant formulation (D-sample) could be prepared by ‘freeze-dry with PEG/dispersion’ just mixing of tri-PCG-Acryl micelle dispersion and tri-PCG/DPMP micelle dispersion with PEG, that can be prepared in 30 s from the dried samples. The obtained D-sample showed irreversible gelation and long duration time of gel state, which was basically the same as the formulations prepared by the usual heating dissolution method (S-sample). Interestingly, the D-sample could maintain its sol state for a longer time (24 h) after preparing the formulation at r.t. compared with the S-sample, which became a gel in 3 h after preparing. The IP system showed good biocompatibility and long duration time of the gel state after subcutaneous implantation. These characteristics of D-samples, quick extemporaneous preparation and high stability in the sol state before injection, would be very convenient in a clinical setting.

A generic framework for multi-field two-phase flow based on the two-fluid model

Abstract Multiphase computational fluid dynamics (MCFD) simulation based on the two-fluid model has emerged as a valuable tool for a wide range of engineering applications. The classical two-field, two-fluid model treats each phase as a whole, which may introduce considerable uncertainties when a phase is comprised of significantly different forms, e.g. , liquid droplets and liquid film, and/or vapor bubbles and continuous vapor core. This uncertainty becomes particularly important for resolving the multi-dimensional distribution of different fields in CFD applications. In relation to this, a multi-field model is necessary to mechanistically model a wide range of two-phase flow regimes. In this paper, a generic and rigorous multi-field two-fluid framework is derived based on the local instant formulation of the mass, momentum and energy conservation equations for single-phase fluids. The averaged field conservation equations and interfacial jump conditions are obtained from the local instantaneous formulation through a derivation with minimal assumptions. Based on this framework, a six-field two-fluid model is proposed as a practical model for typical two-phase flows in industrial systems, in which the flow regimes may span from bubbly to annular. These six fields include: continuous liquid, two dispersed liquid fields, continuous gas, and two dispersed gas fields. The field boundaries and different types of closure relations required to close the model are briefly discussed. The relationship between the momentum transfer terms in the Eulerian two-fluid model and the particle forces have been established by introducing a statistical averaging and the equation of motion for a single particle.

Thermal Mechanical Modeling of the Plunge Stage During Friction-Stir Welding of Dissimilar Al 6061 to TRIP 780 Steel

In this study, a coupled thermomechanical model has been developed for the plunge stage of friction-stir welding (FSW) for joining dissimilar Al 6061 to TRIP steel. Governing equations of mass, momentum, and energy have been formulated for the bulk material and the interface, respectively. Generalized material properties defined with the field variable α are introduced for material identification at different regions. Local instant formulation based on binary phase flow theories has been proposed for developing conservation equations at the interface. These analytical derivations are then implemented into a finite-element model for numerical simulations. In the early stage of plunging, the estimated axial force correlates well with the experimental results, where a short plateau can be observed before the final peak occurs. Discrepancies at the later stage can be attributed to different experimental configurations and related simplified model assumptions.

Experimental study of internal two-phase flow induced fluctuating force on a 90° elbow

Abstract Experiments were performed with a 52.5 mm I.D., 90° elbow to study the internal two-phase flow induced fluctuating forces on pipe bends. The dynamic force signals were obtained directly from force sensors by separating the natural frequency of test section from the predominant frequency of excitation forces. A total of 36 tests were carried out to cover bubbly, slug, churn and annular flows. The results showed that for a fixed liquid flow rate, the predominant frequency of force peaked at slug flow regime. The root mean square value of force fluctuations continuously increased with gas flow rate and reached its maximum in annular flow regime. The excitation force presented a strong dependence on the momentum flux of two-phase flows. The integral of local pressure measurements could predict the time averaged momentum flux change reasonably well. However, the root mean square values of fluctuating forces were quite different due to the additional effect caused by the impact of liquid slugs on the elbow. The impact force, which has not been emphasized in the literature for the internal two-phase flow induced vibration analysis, is found to be significant in determining the force fluctuations in the slug flow regime. A two-phase flow induced excitation force model was developed based on the local instant formulation of two-fluid model. Analyses showed that the high frequency fluctuating components of centrifugal forces could be damped by the integral effect of the elbow.

Modeling of turbulent transport term of interfacial area concentration in gas–liquid two-phase flow

Abstract A modeling of basic transport equation and constitutive equations of turbulent transport terms of interfacial area concentration was carried out. Based on the local instant formulation, interfacial area concentration was formulated in term of spatial correlation functions of characteristic function (local instant volume fraction) and its directional derivative of each phase. In the basic transport equations, interfacial area concentration is transported by time averaged interfacial velocity. In the previous models, interfacial velocity is roughly approximated by velocity of each phase. In the present model, interfacial velocity is formulated in term of spatial correlation functions of characteristic function and velocity of each phase and their directional derivatives. In this formulation, the time averaged interfacial velocity was shown to be correlation functions of fluctuation of velocity and local instant void fraction and their derivatives which reflect the transport of interfacial area concentration due to interaction between interfacial area and turbulence of each phase. Basic conservation equations of spatial correlation functions of characteristic function and velocity of each phase were also derived based on the conservation equations momentum and its fluctuation of each phase. For practical purpose, further modeling of this turbulent transport terms of interfacial area concentration was carried out. As a result, constitutive equations of turbulent diffusion and lateral migration of interfacial area concentration were obtained which can be applied to various flow regime of two-phase flow.

1D unified mathematical model for environmental flow applied to steady aerated mixed flows

Hydraulic models available in literature are unsuccessful in simulating accurately and efficiently environmental flows characterized by the presence of both air–water interactions and free-surface/pressurized transitions (aka mixed flows). The purpose of this paper is thus to fill this knowledge gap by developing a unified one-dimensional mathematical model describing free-surface, pressurized and mixed flows with air–water interactions. This work is part of a general research project which aims at establishing a unified mathematical model suitable to describe the vast majority of flows likely to appear in civil and environmental engineering (pure water flows, sediment transport, pollutant transport, aerated flows…). In order to tackle this problem, our original methodology consists in both time- and space-averaging the Local Instant Formulation, which includes field equations for each phase taken separately and jump conditions, over a flow cross-section involving a free-surface. Subsequently, applicability of the model is extended to pressurized flows as well. The first key result is an original 1D Homogeneous Equilibrium Model which describes two-phase free-surface flows. It is proven to be fundamentally multiphase, to take into account scale heterogeneities of environmental flow and to be very easy to solve. Next, applicability of this free-surface model is extended to pressurized flows by using the classical Preissmann slot concept. A second key result here is the introduction of an original negative Preissmann slot to simulate sub-atmospheric pressurized flows. The model is then closed by using constitutive equations suitable for air–water flows. Finally, this mathematical model is discretised by means of a finite volume scheme and validated by comparison with experimental results from a physical model in the case of a steady flow in a large scale gallery.

Stability of natural convection in superposed fluid and porous layers: Equivalence of the one- and two-domain approaches

Stability analyses of thermal and/or solutal natural convection in a configuration composed by a fluid layer overlying a homogeneous porous medium have been performed using different modeling approaches, especially for the treatment of the interfacial region. Comparisons between the one-domain approach and the two-domain formulation have shown important discrepancies of the marginal stability curves. This note shows that, according to Kataoka [I. Kataoka, Local instant formulation of two-phase flow, Int. J. Multiphase Flow 12(5) (1986) 745–758.], the differentiation of the macroscopic properties of the porous layer at the interface (porosity, permeability, thermal effective diffusivity) must be considered in the meaning of distributions. In that case, the one- and the two-domain approaches are shown to be equivalent and very good agreement is indeed found when comparing the results obtained with both approaches.

A novel approach to color matching of automotive coatings

The coatings industry requires a fast and accurate color formulating process. Today the manual/visual color matching procedures are time consuming and require high skills, in particular when metallic and pearlescent colors are involved. For that reason, a new approach to the colorimetry of paints was followed. This resulted in the development of a system employing an easy to use instrument and powerful software allowing instant formulation of almost any desired color. The system comprises a portable multi-angle spectrophotometer in combination with a personal computer and dedicated color matching software. Development of both the instrument and the software resulted from research on optics, vision science, color mixing properties and computational procedures. In the software new algorithms describing the light-paint interactions (absorption and scattering) and the procedures applied at on site color matching are imbedded. The system retrieves the optimum paint formula through fully automated multi-angle spectral measurements followed by an analysis of the spectra and subsequent data bank search. When desired, correction procedures allow adjustment of the formula through additional measurements on a spray out sample.

Basic Equations and Their Mathematical Feature of Gas-Liquid Two-Phase Dispersed Flow Based on Two-Fluid Model

In order to analyze accurately the thermohydrodynamic behavior of gas-liquid two-phase flows, it is important to obtain the appropriate basic equations of mass, momentum and energy conservation. The basic equations presently used are obtained based on the two-fluid model assuming that both phases are continuous fluid. However, when these equations are applied to a dispersed flow such as a bubbly or droplet flow, problems arise regarding matters such as the physical interpretation of each term and ill-posedness. In view of the above, simplified and physically reasonable basic equations for gas-liquid dispersed flows were developed based on the assumptions that phase change rate and/or chemical reaction rate are not so large at interface, that there is no heat generation in a dispersed phase and that a dispersed phase can be treated as isothermally rigid particles. Based on the local instant formulation of mass, momentum and energy conservation of the dispersed flow, time-averaged equations were obtained. It is shown that, in the derived averaged momentum equation, the terms of pressure gradient and viscous momentum diffusion do not appear and that, in the energy equation, the term of molecular thermal diffusion heat flux does not appear. These characteristics of the derived equations were shown to be very consistent concerning the physical interpretation of the gas-liquid dispersed flow. Furthermore, the basic equations obtained always maintained their well-posedness as regards the initial value problem.

BASIC EQUATION OF TURBULENCE AND MODELING OF INTERFACIAL TRANSFER TERMS IN GAS-LIQUID TWO-PHASE FLOW

Abstract Turbulence is one of the most important phenomena in analyzing thermohydrodynamic characteristics of gas-liquid two-phase flow. For the purpose of accurate prediction of the turbulence phenomena, a basic conservation equation of Reynolds stress was derived based on the local instant formulation of mass and momentum conservations of two-phase flow. In this equation, interfacial transfer terms of turbulence appear as source terms. Detailed considerations on these transport terms were carried out. It was shown that they consist of a viscous damping term due to small scale interfacial structures, a drag induced turbulence generation term due to large scale interfacial structures and a term representing the exchange between surface energy and turbulence. Based on the mechanistic modeling and turbulence modulations, carried out were physical interpretations of interfacial area concentrations of small and large scale interfacial structures, a viscous damping term due to small scale interface and turbulence generation term due to large scale interface.

Basic equations of turbulence in gas-liquid two-phase flow

Basic equations of turbulence in gas-liquid two-phase flow were derived. Based on the local instant formulation of two-phase flow and its averaging, the conservation equations of mass and momentum were obtained for the fluctuating part of the velocity. From these equations, the conservation equations of turbulent energy and turbulent dissipation were derived. In the equation of turbulent energy, interfacial terms were composed of turbulence production due to the relative velocity between the two phases and the exchange between turbulent and surface energy. In the equation of turbulent dissipation, many interfacial terms appear. Some discussions on these interfacial terms and their physical aspects are presented.

Local instant formulation of two-phase flow

Abstract The local instant formulation of mass, momentum and energy conservations of two-phase flow has been developed. Distribution, an extended notion of a function, has been introduced for this purpose because physical parameters of two-phase flow media change discontinuously at the interface and the Lebesgue measure of an interface is zero. Using a characteristic function of each phase, the physical parameters of two-phase flow have been defined as field quantities. In addition to this, the source terms at the interface are defined in terms of the local instant interfacial area concentration. Based on these field quantities, the local instant field equations of mass, momentum and total energy conservations of two-phase flow have been derived. Modification of these field equations gives the single field representation of the local instant field equations of two-phase flow. Neglecting the interfacial force and energy, this formulation coincides with the field equations of single-phase flow, except in the definition of differentiation. The local instant two-fluid formulation of two-phase flow has also been derived. This formulation consists of six local instant field equations of mass, momentum and total energy conservations of both phases. Interfacial mass, momentum and energy transfer terms appear in these equations, which are expressed in terms of the local instant interfacial area concentration.

Jump conditions and entropy sources in two-phase systems. Local instant formulation

The continuum mechanics of two-phase systems involving surface tension and surface properties is discussed. The integral forms of the balance laws are given for the following quantities: mass, linear momentum, angular momentum, total energy and entropy. Starting from these integral balance laws, the jump conditions and the entropy source at the interface are derived. Cet article a pour objet la mécanique des systèmes diphasiques lorsque l'on prend en compte la tension interfaciale et les propriétés thermodynamiques de l'interface. Les formes intégrales des bilans de masse, de quantités de mouvement linéaire et angulaire, d'énergie totale et d'entropie sont posées a priori. Partant de ces lois globales, on calcule les conditions d'interface et la source d'entropie à l'interface. Die Kontinuummechanik von Zweiphasensystemen, unter Beruecksichtigung von Oberflaechenspannung und Oberflaecheneigenschaften, wird behandelt. Bilanzgleichungen in integraler Form werden fuer die folgenden Groessen angegeben: Masse, Bewegungsgroesse, Drall, Gesamtenergie und Entropie. Ausgehend von diesen integralen Bilanzgleichungen werden die Sprungbedingungen und die Entropiequelle in der Zwischenschicht abgeleitet. B cтaтьe paccмaтpиBaeтcя мeчaникa кoнтинyyмa дByчфaзныч cиcтeм, Bключaющич пoBepчнocтнoe нaтяжeниe и пoBepчнocтныe чapaктepиcтики. Интeгpaльныe фopмы cooтнoшeний бaлaнca дaны для cлeдyющич Beличин: мaccы, линeйнoгo мoмeнтa кoличecтBa дBижeния, yглoBoгo мoмeнтa кoличecтBa дBижeния, oбщeй энepгии и энтpoпии. Иcчoдя из этич интeгpaльныч cooтнoшeний бaлaнca, ycлoBия cкaчкa и иcтoчник энтpoпии нa пoBepчнocти paздeлa пoлyчaютcя.