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This document is an editorial from the journal Pharmaceutics, which celebrates its 15th anniversary and highlights advancements in process and formulation modeling in the pharmaceutical industry. The editorial emphasizes the significance of modeling in product development and discusses different types of models available to scientists and engineers. It also provides a summary of the articles included in a special issue of the journal, covering topics such as nanosuspensions, computational techniques, laser ablation, and wet granulation. The editorial concludes by summarizing the main findings from each contribution in the special issue. These studies offer valuable insights into improving drug delivery efficiency and enhancing pharmaceutical manufacturing processes. [Extracted from the article]

Spray drying is a widely used unit operation in synthesis of particles for production of chemicals, food, and pharmaceuticals. However, accurate control and development of this unit remains an elusive task because of the complex interactions of variables and phenomena. In this paper, we adopt and present a dynamic model of the complete drying process for a laboratory spray dryer. The dynamic mathematical model, which integrates atomization, evaporation, and particle formation models, is described by mass and energy balances. The model can predict temperature, residual moisture, and particle size of the produced powder. Model predictions are verified through datasets collected from a lab-scale spray dryer. A data-driven model based on the dynamic model is produced to interface with the control strategy. A model predictive control (MPC) strategy is then adopted to address the highly cross-coupled effects among different components of the dryer and guarantee desired product quality measures. Successful MPC implementation on the drying system is addressed, including trajectory tracking and disturbance rejection scenarios. [ABSTRACT FROM AUTHOR]

Recently, remarkable developments have taken place, leading to significant improvements in microfluidic methods to capture subtle biological effects down to single cells. As microfluidic devices are getting sophisticated, design optimization through experimentations is becoming more challenging. As a result, numerical simulations have contributed to this trend by offering a better understanding of cellular microenvironments hydrodynamics and optimizing the functionality of the current/emerging designs. The need for new marketable designs with advantageous hydrodynamics invokes easier access to efficient as well as time-conservative numerical simulations to provide screening over cellular microenvironments, and to emulate physiological conditions with high accuracy. Therefore, an excerpt overview on how each numerical methodology and associated handling software works, and how they differ in handling underlying hydrodynamic of lab-on-chip microfluidic is crucial. These numerical means rely on molecular and continuum levels of numerical simulations. The current review aims to serve as a guideline for researchers in this area by presenting a comprehensive characterization of various relevant simulation techniques. [ABSTRACT FROM AUTHOR]

Driven by the new trend to build quality into products and reducing empiricism, small-scale screening techniques have been frequently used to evaluate, thermodynamic of drug solubility in the polymer, and drug-polymer kinetic amorphous miscibility. In this paper, these methods have been overviewed to shed light on their liabilities in predicting spray-dried amorphous solid dispersions' (ASDs) properties. By scrutinizing relevant open literature, several inconsistencies have been recognized, deemed to be due to the inability of conventional miniaturized means to simulate the spray drying process operations/constraints in formulating active pharmaceutical ingredients (APIs). Given the complex interplay of thermodynamics of mixing, heat and mass transfer, and fluid dynamics in this process, scaling rules have been introduced to remedy arisen issues in conventional miniaturized tools. Accordingly, spray drying process is analyzed considering the fundamental physical transformations involved, i.e. atomization and drying. Each transformation is explored from a scaling perspective with an emphasis on key response factors, and ways to retain them for each transformation across scales. Prospective bifurcated developments may improve the odds of successful formulations/process conditions later on during development stages. [ABSTRACT FROM AUTHOR]

Spray drying is one of the widely used manufacturing processes in pharmaceutical industry. While there are voluminous experimental studies pertaining to the impact of various process-formulation parameters on the quality attributes of spray dried powders such as particle size, morphology, density, and crystallinity, there is scant information available in the literature regarding process scale-up. Here, we first analyze salient features of scale-up attempts in literature. Then, spray drying process is analyzed considering the fundamental physical transformations involved, i.e., atomization, drying, and gas-solid separation. Each transformation is scrutinized from a scale-up perspective with non-dimensional parameters & multi-scale analysis, and comprehensively discussed in engineering context. Successful scale-up entails similar key response variables from each transformation across various scales. These variables are identified as droplet size distribution, outlet temperature, relative humidity, separator pressure loss coefficient, and collection efficiency. Instead of trial-and-error-based approaches, this review paper advocates the use of mechanistic models and scale-up rules for establishing design spaces for the process variables involved in each transformation of spray drying. While presenting a roadmap for process development and scale-up, the paper demonstrates how to bridge the current gap in spray drying scale-up via a rational understanding of the fundamental transformations. [ABSTRACT FROM AUTHOR]

The scaling-up of spray drying processes is an important and challenging step in commercializing specialty products with an ensured quality because it mandates a comprehensive understanding of several steps in the process such as atomization, efficient solvent removal, and particle segregation. The formation of needed particle sizes and shapes is impossible without appropriate atomization through spray dryer nozzles. Hence, research is discussed that investigates the atomization mechanism for a pilot scale externally-mixed, two-fluid nozzle spray dryer by using time resolved particle-image velocimetry to study the behavior of droplets in the near-field of the nozzle tip. Important near-field dynamics of droplets emanating from the nozzle are described, and particle formation characteristics are discussed for several formulations which are widely used in the pharmaceutical industry. Spray angle, droplet breakup length, and droplet sizes and velocity distributions are characterized. Understanding these parameters assists the interpretation of particle formation and enables the modeling of the spray drying process. [ABSTRACT FROM AUTHOR]

Automotive spray painting is among the most sophisticated and controlled industrial painting operations currently performed. Nevertheless, improvements in it are still sought in efforts to minimize the costs, the energy use and the environmental impacts. One compelling aspect of improvement is the paint transfer efficiency, i.e. the amount of paint that remains on a vehicle relative to the amount supplied to the paint applicator during coating operations, because currently it has been estimated that the overall paint transfer efficiency in the automotive industry is between 50% and 60%. Hence, this review assesses current automotive spray coating technologies with respect to their transfer efficiencies and discusses the fundamental and operational parameters that influence it. A comprehensive characterization of paint spray applicators (air sprayers, high-volume low-pressure sprayers, airless sprayers, air-assisted airless sprayers, rotary bell atomizers, electrostatic sprayers, and effervescent atomizers) is included. Some problems associated with evaluating and improving their paint transfer efficiencies are discussed. Also, the potential of and the technology needs for developing these applicators are considered. [ABSTRACT FROM AUTHOR]

A complete description of the particle formation process can only be realized with techniques that enable the measurement of the composition and structural dependence of individual particles. The purpose of this publication is to highlight the utility of one such high resolution imaging technique; focused-ion scanning electron microscopy (FIB-SEM). As a model system, amorphous dispersion particles of felodipine and polyvinylpyrrolidone (PVP) were prepared by spray drying and used to interrogate single particles. Further, FIB-SEM was coupled with energy dispersive X-ray analysis (EDX) to characterize spatial chemical distributions in spray dried amorphous solid dispersion particles. Within a single spray drying batch, individual particles exhibited different phase behavior as a function of particle size. Larger particles showed notable amorphous-amorphous phase separation while smaller particles showed uniform composition. The morphology of particles was also found to be a function of particle size. Larger particles were consistently more porous in nature compared to smaller particles. The observed differences in compositional heterogeneity of different spray dried particles as a function of size are interpreted via theoretical arguments based on the Peclet number, the ratio of the evaporative flux of the solvent to the diffusive flux of the drug and the polymer within the droplet. Phase behavior may also be interpreted in terms of equilibrium ternary phase diagrams. Regardless, commonly used bulk physical and chemical characterization techniques may be used to establish correlations between the nature of the dispersion and the processing parameters. However, these techniques lack the resolution to provide a scientific link between the processing conditions and the nature of individual particles. The current paper highlights the utility of high resolution morphological and compositional measurements of individual particles. [ABSTRACT FROM AUTHOR]

Automotive coatings and the processes used to coat automobile surfaces exemplify the avant-garde of technologies that are capable of producing durable surfaces, exceeding customers' expectations of appearance, maximizing efficiency, and meeting environmental regulations. These accomplishments are rooted in 100 years of experience, trial-and-error approaches, technique and technology advancements, and theoretical assessments. Because of advancements directed at understanding the how, why, when, and where of automobile coatings, the progress in controlling droplets and their deposition attributes, and the development of new technologies and paint chemistries, a comprehensive and up-to-date review of automobile coatings and coating technologies was considered to be of value to industrial practitioners and researchers. Overall, the critical performance factors driving the development and use of advanced automotive coatings and coating technologies are (a) aesthetic characteristics; (b) corrosion protection; (c) mass production; (d) cost and environmental requirements; and (e) appearance and durability. Although the relative importance of each of these factors is debatable, the perfection of any one at the expense of another would be unacceptable. Hence, new developments in automotive coatings are described and discussed in the following review, and then related to improvements in production technologies and paints. Modern automotive coating procedures are also discussed in detail. Finally, an extrapolation into the future of automotive coating is offered with a view of the developments and technologies needed for an increasingly efficient and more sustainable coatings industry. [ABSTRACT FROM AUTHOR]

This paper deals with the influence that the internal shape of open cavities exerts on the Constructal design of a heat generating body. Several shapes of cavity are studied: triangular, elliptical, trapezoidal and Y-shaped cavities intruding into a trapezoidal shaped solid with uniform heat generation. The trapezoidal solid is commonly used in round electronic devices. The geometric aspect ratios of the cavities and the solid are free to vary while the total volume occupied by the solid and the cavity are fixed. The objective is minimizing the peak (hot spot) temperature with respect to the geometrical parameters of the system. Finite element method is employed to calculate the peak temperature of the solid. With respect to the Constructal thermal design, the numerical results prove that, utilizing the triangular and Y-shaped cavities can result more reliable and effective rather than other studied cavities. [ABSTRACT FROM AUTHOR]

The flow of an incompressible electrically conducting viscous fluid in convergent or divergent channels under the influence of an externally applied homogeneous magnetic field is studied both analytically and numerically. Navier-Stokes equations of fluid mechanics and Maxwell's electromagnetism equations are reduced into highly non-linear ordinary differential equation. The resulting non-linear equation has been solved analytically using a very efficient technique, namely, differential transform method (DTM). The DTM solution is compared with the results obtained by a numerical method (shootingmethod, coupled with fourth-order Runge-Kutta scheme). The plots have revealed the physical characteristics of flow by changing angles of the channel, Hartmann and Reynolds numbers. [ABSTRACT FROM AUTHOR]

Despite the wide-spread applications of spray drying in the production of chemicals, food, and pharmaceuticals, accurate control and development of this unit remains an elusive task because of the complex interactions of variables and phenomena. In this paper, we offer the development of a computationally efficient closed-loop system with a model predictive controller (MPC) where a computational fluid dynamics (CFD) process model is utilized to represent the process behavior. In particular, we present the development of an MPC and its implementation within the CFD model of a lab-scale spray dryer. Dynamic model is created with an adopted CFD model based on a 2D axisymmetric dryer, and Reaction Engineering Approach (REA)- as the drying kinetic method. Then, an MPC control strategy is designed using a linear approximation of a data-driven dynamic model and implemented within the CFD simulation as a user-defined function (UDF). We demonstrate the application of the developed MPC within the CFD simulation to address highly cross-coupled effects among different components of the dryer and guarantee desired product quality measures even in the presence of various disturbances. The proposed MPC embedded CFD modeling tool can serve as an efficient control strategy for other thermo-fluid systems as well. [Display omitted] [ABSTRACT FROM AUTHOR]