Drug absorption is determined by the drugs physicochemical properties, formulation, and route of administration. Pharmaceutical factors a chemical factors b physicochemical properties of drug substances 1. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Physico chemical factors affecting drug absorption youtube. Sep 19, 2014 3 factors affecting drug absorption physicochemical factors. A mechanistic approach to understanding the factors affecting. List two physiologic factors that can alter each of the processes of absorption, distribution, and excretion. Factors affecting drug absorption linkedin slideshare. For the love of physics walter lewin may 16, 2011 duration. Physicochemical and biopharmaceutical properties that.
Regarding the physicochemical factors affecting the absorption of drugs. The rate and extent of oral drug absorption is determined by a complex interaction between a drugs physicochemical properties, gi physiologic factors, and the nature of the formulation administered. Download as pptx, pdf, txt or read online from scribd. Overview of factors affecting oral drug absorption. This chapter discusses the passive diffusion of an orally absorbed drug. These properties are important for dosage form design. These include particle size, solubility, surface 2. Describe two types of drug interaction and explain how. Formulation factors affecting drug product performance. After reading this article you will learn about the pharmaceutic factors affecting drug bioavailability. A mechanistic approach to understanding the factors. May 29, 2018 for the love of physics walter lewin may 16, 2011 duration. The oral absorption of any chemical entity reflects a complex spectrum of events. Physicochemical and physiological mechanisms for the effects of food on drug absorption.
Worlds best powerpoint templates crystalgraphics offers more powerpoint templates than anyone else in the world, with over 4 million to choose from. The presence of food within the gi tract impacts significantly on transit profiles, ph, and its solubilization capacity. This chapter discusses the physicochemical properties of the drug and dosage form factors that influence bioavailability. Theyll give your presentations a professional, memorable appearance the kind of sophisticated look that todays audiences expect. Winner of the standing ovation award for best powerpoint templates from presentations magazine. Physicochemical factors of drugs affecting absorption, distribution, and excretion. Other factors such as dose and drug stability in the intestinal medium, which can significantly impact oral absorption, must also be considered. Explain how bioavailability can impact drug response and product selection. Impact of physiological, physicochemical and biopharmaceutical factors in absorption and metabolism mechanisms on the drug oral bioavailability of rats and humans 480 expert opin. Phenols another commonly encountered acidic functional group found in drug molecules is phenol, or. Physicochemical and biopharmaceutical properties that affect drug absorption of compounds absorbed by passive diffusion. Invitro dissolution testing or drug release testing may be used for seeking waiver of required product to conduct invivo bioavailability or bioequivalence studies. Physicochemical properties effect on absorption of drugs slideshare. The rate and extent of oral drug absorption is determined by a complex interaction between a drugs physicochemical properties, gi physiologic factors, and the.
In order to develop a drug product that elicits the desired therapeutic objective, the pharmaceutical scientist must have a thorough understanding of the biopharmaceutic properties of the drug and drug product and the physiologic and pathologic factors affecting drug absorption from the application site. In each region, the absorption rate increased with the drug lipophilicity. Physicochemical factors affecting absorption authorstream. The factors affecting absorption of drugs are related both to the drugs and to the body factors related to drugs. As discussed in chapter 19, the rate and extent of drug absorption are influenced by the physiological factors associated with the structure and function of the gastrointestinal tract. Models predictive of intestinal drug absorption are important in drug development to identify compounds with promising biopharmaceutical properties. Drug absorption depends on the lipid solubility of the drug, its formulation and the route of administration. These include the physicochemical properties of the administered agent, human physiology, pathology including disease state, the way the drug is presented formulated and possibly the amount that is administered dose.
Thus by understanding the physicochemical properties of a compound and by recognizing the physiological. In oral drug absorption, prediciton and assessment. Logistic regression was applied to establish the relationship between the effect of food positive, negative or no effect on auc of 92 entries and physicochemical parameters, including clinical. Jun 25, 2019 the importance of the physicochemical properties on the dissolution of a drug substance into the dissolution medium is best illustrated by 3. Physicochemical parameters affecting drug action dr. Dosage forms eg, tablets, capsules, solutions, consisting of the drug plus other ingredients, are formulated to be given by various routes eg, oral, buccal, sublingual, rectal, parenteral, topical, inhalational.
Factors related to the physicochemical properties of the drug. Some basic thermodynamic concepts will be introduced, particularly that of thermodynamic activity, an important parameter in determining drug potency. Oral absorption efficiency can be influenced by several factors, acting independently or in concert. In this chapter we examine some of the important physicochemical properties of drugs in aqueous solution which are of relevance to such liquid dosage forms as injections, solutions, and eye drops. The rate and extent of oral drug absorption is determined by a complex. The approach used would enable a cosmetic chemist to predict the relative degree of drug absorption through skin from the physicochemical constants. Since permeability is a factor affecting absorption, cell culture models e. Logistic regression was applied to establish the relationship between the effect of food positive, negative or no effect on auc of 92 entries and physicochemical parameters, including. Pharmaceutic factors affecting drug bioavailability toxicology. Absorption is the transfer of the drug into the bloodstream. The factors affecting absorption of drugs are related both to the drugs and to the body. Food, gastrointestinal ph, and models of oral drug absorption. Several factors can affect the absorption of a drug into the body.
The approach used would enable a cosmetic chemist to predict the relative degree of drug absorption through skin from the physicochemical constants of series of compounds and the absorption data. Physicochemical approaches to enhancing oral absorption. Major process for absorption of more than 90% of drugs. Write in brief about factors affecting drug absorption. Properties pdf win32 programming is required to give optimal absorption. Despite the fact that these three equations are derived from different diffusion mechanisms, they clearly show that the dissolution rate depends on the solubility and surface area of a drug. Greater the lipid water solubility coefficient, more is the lipid solubility of the drug and greater is the absorption. Physicochemical properties of drugs pharmaceutical press. Pharmacists must also understand the relationship of drug dosage to therapeutic efficacy.
Physicochemical factors affecting skin absorption request pdf. This article throws light upon the eight main physiological factors that affect the rate of drug absorption. Write in detail about the factors that are related to the physiological conditions and formulation of dosage form. Bioavailability physicochemical and dosage form factors. Chart and diagram slides for powerpoint beautifully designed chart and diagram s for powerpoint with visually stunning graphics and animation effects. However in other routes of administration the rate and efficiency is dependent on many factors and usually on ly results in partial absorption. In oral drug absorption, prediction and assessment. Assessing physicochemical properties of drug molecules via. Considerations in the design of a drug product to deliver the active drug with the desired bioavailability characteristics and therapeutic objectives include 1 the physicochemical properties of the drug molecule, 2 the type of drug product eg, tablet, capsule, transdermal delivery system, topical ointment, parenteral solution, 3 the. For most drugs, two to fivefold differences in the rate or extent of gastrointestinal absorption can occur, depending on the dosage form. Physicochemical properties effect on absorption of drugs.
Laxatives and diarrhea, which speed up the passage of substances through the digestive tract, may reduce drug absorption. Definitions pharmacokinetics oevaluate the way in which a drug interacts with various barriers within a biological system pharmacodynamics ostudy of the relationship between systemic exposure of a drug and its biological effects on tissue oabsorption can be defined as the movement of active drug or prodrug from the site of administration across biologic. Physicochemical properties of drugs 61 applying knowledge of the pka and an appreciation of the extent to which drugs ionise in solution. The importance of the physicochemical properties on the dissolution of a drug substance into the dissolution medium is best illustrated by 3. Mar 24, 2007 to develop a statistical model for predicting effect of food on the extent of absorption area under the curve of timeplasma concentration profile, auc of drugs based on physicochemical properties. Just as the absorption and distribution of a drug are influenced by its physicochemical properties so is its interaction with the drug metabolising enzymes. Predicting effect of food on extent of drug absorption. Physiological factors and drug absorption pharmacokinetics. A drug substance is considered highly soluble when the highest dose strength is soluble in 90% of an administered dose, based on massbalance or in comparison to an. We classify the physicochemical characteristics of a drug molecule or particle into those that are solely related to chemical structures and those that are related to physical shape eg, crystalline forms. Factors affecting drug absorption and distribution anaesthesia. Each route of drug application presents special biopharmaceutic consideration in designing a drug product. In iv this process is complete thus the whole dose reaches the systemic circulation. A seminar on physicochemical properties affecting drug absorption.
Physicochemical properties of api impact on formulation. Molecular and physicochemical properties impacting. Pdf impact of physiological, and biopharmaceutical. Deductions of this type form the basis ofmedicinal chemistry, the science of rational drug design. Ideally for optimum absorption, a drug should have sufficient aq solubility to dissolve in fluids at absorption site and lipid solubility kow high enough to facilitate the partitioning of the rug in the lipoidal biomembrane i. The systemic absorption of a drug is dependent on 1 the physicochemical properties. Predicting effect of food on extent of drug absorption based. Sustained release oral drug delivery system an overview. Lipid water solubility coefficient is the ratio of dissolution of drug in lipid as compared to water.
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. Dressman received february 20, 1996, from the department of pharmaceutics, victorian college of pharmacy, monash university. Review article physicochemical and physiological mechanisms for the effects of food on drug absorption. A mechanistic approach to understanding the factors affecting drug absorption.
Physicochemical and physiological mechanisms for the. Dissolution testing of immediaterelease products and its application to forcasting in vivo performance. These two characteristics, rate and completeness of absorption, comprise bioavailability. Solubility as a limiting factor to drug absorption. Drugs are absorbed after oral administration as a consequence of a complex array of interactions between the drug, its formulation, and the gastrointestinal gi tract. Compare the roles of passive diffusion and carriermediated transport in drug absorption. The bioavailability of active drug can be varied from rapid and complete absorption to a slow, sustained rate of absorption or. A knowledge of the fate of a drug, its disposition absorption, distribution, metabolism, and excretion, known by the acronym adme and pharmacokinetics the mathematical description of the rates of these processes and of concentrationtime relationships, plays a central role throughout pharmaceutical research and development. Jun 19, 2019 several factors can affect the absorption of a drug into the body. Factors affecting the formulation of oral sustained release drug delivery system 1 physicochemical factors 25 1. Food, other drugs, and digestive disorders can affect drug absorption and bioavailability.
Physicochemical characters affecting absorption physical. Physicochemical parameters affecting drug action posted jun 29, 2014, 10. Physicochemical and physiological mechanisms for the effects. Drug absorption drugs merck manuals consumer version. For example, highfiber foods and calcium supplements may bind with a drug and prevent it from being absorbed. Factors influencing product bioavailability include drug sol ubility, permeability. To develop a statistical model for predicting effect of food on the extent of absorption area under the curve of timeplasma concentration profile, auc of drugs based on physicochemical properties. Physicochemical factors drug solubility and dissolution rate solubility amount of a substance called the solute that dissolves in a unit volume of a liquid substance called the solvent to form a saturated solution under specified conditions of temperature and pressure.
Consequently, food would be expected to affect the absorption of co. Factors affecting drug absorption pharmaquest home pages. Physicochemical factors of drugs affecting absorption. Because biological membranes contain a lipid core, they represesnt a lipophilic environment. Physicochemical characters affecting absorption physical properties that are due to shape, size and physical form of any drug molecule, usually unaffected by chemical changes, affect the bioavailability of therapeutic moieties. Ppt physicochemical properties in relation to biological. Pdf overview of factors affecting oral drug absorption. Factors related to the physicochemical properties of the. The absorption rates of the acylsalicylic acids were different in the intestinal regions. Biopharmaceutics is the study of the physicochemical properties of the drug and the drug product, in vitro, on the bioavailability of the drug, in vivo, to produce a desired therapeutic effect. However, it was shown that the absorption rates in the small intestine tended to reach a ceiling at the high lipophilicity. Pharmaceutic factors affecting drug bioavailability. Drug absorption is the movement of a drug from its site of application into the bloodstream. This chapter discusses the physicochemical properties of the drug and.
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