Since the discovery of microemulsions by jack h schulman, there has been huge progress made in applying microemulsion systems in plethora of research and industrial process. Microemulsions have low viscosity compared to emulsions. Microemulsions are shown to be effective dermal delivery mechanism for several active ingredients for pharmaceutical and cosmetic applications. Chemical method, especially microemulsion flooding, plays an important role in enhanced oil recovery technique due to its ability to reduce interfacial. This book is divided into seven chapters that explore the physics and chemistry of microemulsions. Surfactant associates emulsions and microemulsions. Tween 20, 40, 60, and 80 were used separately as surfactant with methanol, ethanol, 1propanol, 1butanol or 1pentanol as cosurfactant, and ipp as oil phase to prepare various microemulsions. The rapidly increasing number of applications for microemulsions has kept this relatively old topic still at the top point of research themes. Remove this presentation flag as inappropriate i dont like this i like this remember as a favorite. Emulsion in which the particles of the dispersed phase have diameters from approximately 1 to 100.
A shown in the photograph is an opaque, white macroemulsion macro and a clear, colorless microemulsion micro of propofol. Microemulsions are optically isotropic systems consisting of water, oil and amphiphile. Thus, for lipophilic drug compounds that exhibit dissolution ratelimited absorption, these systems. The formation of a surfactant film around droplets facilitates the emulsification process and also tends to minimize the coalescence of droplets.
Microemulsions is the property of its rightful owner. Microemulsions are potentially quite powerful alernative carrier system for delivery because of high solubilization capacity, transparency, thermodynamic stability, ease of preparation, and high diffusion and absorption rates through skin, when compared to solvent without the surfactant system. The adobe flash plugin is needed to view this content. Ppt microemulsions powerpoint presentation free to. Hydrogels, microemulsion, nanoparticles, organogels, polymerization. In addition, microemulsions are thermodynamically stable and spontaneously forming, making them easy to prepare. Thus, for lipophilic drug compounds that exhibit dissolution rate. Acaadeemmiiccsscciieenncessinternational journal of. Microemulsions are prepared by the spontaneous emulsification method phase titration method and can be depicted with the help of phase diagrams.
Oil in water microemulsions wherein oil droplets are dispersed in the continuous aqueous phase. Microemulsions, on the other hand, are thermodynamically stable. Apart from being more commercially viable due to its lower energy requirements, microemulsions are also attracting the interest of researchers due to their potential as drug delivery vehicles, in 1 chandra, a1992. Emulsions and microemulsions are both stable dispersions of oilinwater or waterinoil. Structurally, they are divided in to oil in water ow, water in oil wo and bicontinuous microemulsions. Worlds best powerpoint templates crystalgraphics offers more powerpoint templates than anyone else in the world, with over 4 million to choose from. A generic phase diagram resulting from such analysis is shown in figure 1. Microemulsions are readily distinguished from normal emulsions by their transparency, low viscosity and more fundamentally their thermodynamic stability. Microemulsions are clear, thermodynamically stable, isotropic liquid mixtures of oil, water and surfactant, frequently in combination with a cosurfactant. Ppt microemulsions powerpoint presentation free to view id. Properties and applications provides a complete and systematic assessment of all topics affecting microemulsion performanc. Basic aspects of microemulsion microemulsion are fluid, transparent, thermodynamically stable oil and water system and stabilized by a surfactant usually in conjunction with cosurfactant.
Formulation and characterization of microemulsion system. These metrics are regularly updated to reflect usage leading up to the last few days. Ppt microemulsions powerpoint presentation free to view. Micelles, microemulsions, liquid crystals, and the structure.
This book provides an assessment of some issues influencing the characteristics and performance of the microemulsions, as well as their main types of applications. Propofol possesses several favorable characteristics, including an antiemetic effect and rapid emergence from unconsciousness with minimal residual drowsiness. Microemulsions are really single phase systems in which the structure contains fusioned oil. If so, share your ppt presentation slides online with. Design and evaluation of microemulsions for improved. Pdf in the past twenty five years, microemulsions have been the focus of extensive. These are a special kind of colloidal dispersion that have attracted a great deal of attention because of their ability to solubilise otherwise insoluble materials. Properties and applications provides a complete and systematic assessment of all topics affecting microemulsion performance and discusses the fundamental characteristics, t. Emulsions part 3 microemulsions miniemulsions remarks to. Microemulsions act as supersolvents for drug, can solubilise both hydrophilic and lipophilic drugs including drugs that are insoluble in both aqueous and hydrophobic solvents. Microemulsion provides very efficient approach in oil extraction from oilseed on. Microemulsions are thermodynamically stable dispersions of oil and water stabilized by a surfactant and, in many cases, also a cosurfactant. Introduction to macro and microemulsions acs symposium.
Microemulsions are thermodynamically stable system and allows selfemulsification of the system. Microemulsions are thermodynamically stable, and their formation is facilitated by the ultralow interfacial tension of these systems, which leads to the formation of extremely small droplets of the dispersed phase. The microemulsion definition provided by danielson and lindman in 1981 will be used as the point of reference. Mes are widely investigated for preparing personal care products with superior. For example, ow and wo microemulsions show newtonian behavior over a wide range of shears, while the bicontinuous phase may undergo breakage upon medium shear forces, leading to thinning. Microemulsions, surfactants, cosurfactants, thermodynamic stability, phase behavior, novel carriers. The altmetric attention score is a quantitative measure of the attention that a research article has received online. The aqueous phase may contain salt s andor other ingredients, and the oil may actually be a complex mixture of different hydrocarbons and olefins.
In chapter 1 a short introduction about the background, various aspects and applications. A microemulsion is a thermodynamically stable fluid. Winner of the standing ovation award for best powerpoint templates from presentations magazine. Microemulsions this chapter is devoted to another important property of surfactants, that of stabilization of wateroil films and formation of microemulsions. The term microemulsion refers to a thermodynamically stable isotropically clear dispersion of two immiscible liquids, such as oil and water. Continue microemulsions are dispersions of nanometersized droplets of an immiscible liquid within another liquid. In contrast to ordinary emulsions, microemulsions form upon simple mixing of the components. Microemulsions are isotropic, thermodynamically stable transparent or translucent systems of oil, water and surfactant, frequently in combination. Historical background definition composition of microemulsion major goals advantages disadvantages macroemulsion vs microemulsion types of microemulsions preparation methods of microemulsions equipments used for the preparation of microemulsions formation of microemulsion factors affecting. Microemulsions in food industry uses and applications. Enhancement of antioxidant and skin moisturizing effects. Chemical method, especially microemulsion flooding, plays an important role in enhanced oil recovery technique due to its ability to reduce interfacial tension between. Characterization of microemulsions prepared using isopropyl. The main driving force for microemulsion formation is the ultra low interfacial tension, which is usually achieved by the use of two or more emulsifiers scos.
The trend of growing interest in alternative source of energy focuses on renewable products worldwide. Important uses and applications of microemulsions in food industry will also be discussed. Dec 15, 2008 the effective use of microemulsions has increased dramatically during the past few decades as major industrial applications have expanded in a variety of fields. Microemulsions are isotropic, thermodynamically stable systems composed of oil, water, surfactant s and cosurfactants cos or cosolvents. Chart and diagram slides for powerpoint beautifully designed chart and diagram s for powerpoint with visually stunning graphics and animation effects. Photograph and cartoons of a macroemulsion and microemulsion of propofol.
Temperature range in which an ow microemulsions inverts to a wo type. Theory and practice covers the development of the theory and practice of microemulsion systems. This book deals first with the commercial history of microemulsions, from the discovery of carnauba wax emulsions to polymer emulsions. Because of the small particle sizes, microemulsions appear as clear or translucent solutions. Theyll give your presentations a professional, memorable appearance the kind of sophisticated look that todays audiences expect. When compared with emulsions, which are sensitive and metastable dispersed forms, smedds are physically stable formulations that are easy to manufacture. Bicontinuous microemulsions wherein micro domains of oil and water are inter dispersed within the system. Historical background definition composition of microemulsion major goals advantages disadvantages macroemulsion vs microemulsion types of microemulsions preparation methods of microemulsions equipments used for the preparation of microemulsions formation of. Preparing a pharmaceutically acceptable dosage form demands a clear. Microemulsions mes represent a promising delivery system for pharmaceuticals and cosmeceuticals due to its numerous advantages over the existing conventional formulations. In several regions of the phase diagram, single phases exist in one. The particle size of microemulsions ranges from about 10300 nm. Droplet formation is facilitated by the addition of surfactants and often also co surfactants.
In the case of oilinwater microemulsions, the steadystate fluorescence technique was successfully applied 36. Enhancement of antioxidant and skin moisturizing effects of. During emulsion formation, the deformation is opposed by the laplace pressure. Microemulsions potential carrier for improved drug delivery. Discusses important issues related to enzymatic reactions and nanoparticle formation. It is different from kinetically stable emulsions which will be break into oil and water over time. Therefore, the disruption of droplets is a critical step in the process of emulsification. Sep 24, 2014 the trend of growing interest in alternative source of energy focuses on renewable products worldwide. Micelles, microemulsions, liquid crystals, and the. This chapter is devoted to another important property of surfactants, that of stabilization of wateroil films and formation of microemulsions. The effective use of microemulsions has increased dramatically during the past few decades as major industrial applications have expanded in a variety of fields.
In particular, the high solubilizing power of microemulsions and microemulsion systems for organic and inorganic com. The for mation of final emulsion droplets can be viewed as the stepwise pro cess. In order to prepare wo microemulsions, a cyclohexane was used as the oil phas e and a mixture of poly oxyethylene 5 nonyle phenol ether np5, chemical purity and poly oxyethylene 9 nonyle phenol ether with weight ratio 1. The role of interfacial film of surfactants in the formation of these systems has been highlighted. Pdf microemulsions mes have attracted much interest over the past years as.
Preparation require intense agitation for their formation. B and c cartoon demonstrating the relative particle sizes of the macroemulsion b and microemulsion c. Because of the small particle sizes, microemulsions appear as clear. Characterization of microemulsions necessarily begins with the elucidation of the phase behavior, where, in the most simple form, oil, water, and surfactant are mixed in different molar ratios, and the formed phases are tracked.
The aqueous phase may contain salts andor other ingredients, and the oil may actually be a complex mixture of different hydrocarbons and olefins. Fills a void in the literature by presenting the basic concepts of microemulsions, essential to understanding their industrial significance, and comprehensive descriptions of the most useful commerical applications. Describe various barriers to ocular drug delivery and constraints with. And they can be known as modern colloidal drug delivery system. Microemulsions or micellar emulsion are dynamic system in which the interface is continuously and spontaneously fluctuating 31. They offer the advantage of spontaneous formation, ease of manufacturing and scaleup, thermodynamic stability, and improved drug solubilization and bioavailability. Surfactants are the principal agents that enable oil and water to mix. Ocular drug delivery aswani dutt vadlapudi, kishore cholkar, supriya reddy dasari, and ashim k. Oil and water are immiscible and they separate into two phases when mixed, each saturated with traces of the other component capek, 1999. Anna zieli skajurek, joanna reszczy ska, ewelina grabowska. Charts the enormous advances that have occurred in the field over the past decade. While some people insist that microemulsions must be transparent, that is not really a critical part of their description. To disperse two immiscible liquids, one needs a third component, namely, the emulsi.
A potential novel drug delivery system jaspreet kaur saini 1, ujjwal nautiyal 1, senthil kumar m 1, devendra singh 2, firoz anwar 3 1department of pharmaceutics, himachal institute of pharmacy, paonta sahib, himachal pradesh, india. Microemulsions are mixtures of oil, surfactant, and water that form spontaneously on bringing the three components together 69. Drug delivery through microemulsions is a promising area for continued research with the aim of achieving controlled release with enhanced bioavailability and for drug targeting to various. Microemulsion, theory, preparation, phase behaviour, structure, properties, application. Macroemulsions comprise large droplets and thus are unstable in the sense that the droplets sediment or float, depending on the densities of the dispersed phase and dispersion medium. Our new crystalgraphics chart and diagram slides for powerpoint is a collection of over impressively designed datadriven chart and editable diagram s guaranteed to impress any audience. Microemulsions are amphiphile aided thermodynamically stable oil in water ow or water in oil wo dispersions. Properties and applications of microemulsions by john klier, christopher j. Learn more about these metrics article views are the countercompliant sum of full text article downloads since november 2008 both pdf and html across all institutions and individuals.
Understand the importance of various routes of drug administration to the eye. However, the situation of petroleum industries in many countries needs much concern in improving the oil recovery technique. Generally obtained by gentle mixing of ingredients. For hemolytic studies, the propofol microemulsions were diluted with 0. Separation of the dispersed and continuous phases usually occurs within time periods from a few. Acaadeemmiiccsscciieenncessinternational journal of pharmacy. Microemulsions a brief introduction 5 microemulsions one must consider all kind of the interactions existing between the components present in the system, i. These latter hold the key to the effect of humidity on skin properties and are the essence of. Microemulsions are amphiphile aided thermodynamically stable. Water in oil microemulsions wherein water droplets are dispersed in the continuous oil phase. Microemulsions are potential drug carrier systems for oral, topical, and parenteral administration. Introduction n search of safe and effective therapy, the development of new drugs has been the common practice historically.
Introduction microemulsions are thermodynamically stable, fluid, optically clear dispersions of two immiscible liquids such as oil and water. Microemulsions based transdermal drug delivery systems. More thermodynamically stable than macro emulsions. In the short course we will give a systematic introduction to the mechanisms of kinetic stabilization of macroemulsions, show how macroemulsions are related. In contrast, emulsions require a large input of mechanical energy for their formation. Microemulsions show varying rheology depending on the phase point. Various propofol microemulsions were assessed for their potential to cause in vitro hemolysis of heparinized fresh human whole blood. Microemulsions are usually characterised by ternary phase diagrams, which three edges are the components of a microemulsion, namely, oil, water and surfactant. In addition, the almost identical system of water, soap, and longchain carbox ylic acid is decisively relevant to the structure of the stratum corneum lipids. However, it involved a long gestation period in terms of time, efforts, and huge cost. In petroleum engineers guide to oil field chemicals and fluids second edition, 2015. Emulsions are stable dispersions of immiscible liquids, but they are not thermodynamically stable. Construction of phase diagram is a useful approach to study the complex series of interactions that can occur when different components microemulsions as promising delivery systems. In wo microemulsions, water droplets are dispersed in the continuous oil phase while ow.
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