Biopharmaceutics: Mechanisms of Drug AbsorptionSURYAKANTVERMA2
Biopharmaceutics is defined as the study of factors influencing the rate and amount of drug that reaches the systemic circulation and the use of this information to optimise the therapeutic efficacy of the drug products.
1. Measurement of Bioavailability:
Direct and indirect methods may be used to assess drug bioavailability. The in-vivo bioavailability of a drug product is demonstrated by the rate and extent of drug absorption, as determined by comparison of measured parameters, e.g., concentration of the active drug ingredient in the blood, cumulative urinary excretion rates, or pharmacological effects.
For drug products that are not intended to be absorbed into the bloodstream, bioavailability may be assessed by measurements intended to reflect the rate and extent to which the active ingredient or active moiety becomes available at the site of action.
The design of the bioavailability study depends on the objectives of the study, the ability to analyze the drug (and metabolites) in biological fluids, the pharmacodynamics of the drug substance, the route of drug administration, and the nature of the drug product.
Pharmacokinetic and/or pharmacodynamic parameters as well as clinical observations and in-vitro studies may be used to determine drug bioavailability from a drug product.
1.1. Pharmacokinetic methods:
These are very widely used and based upon the assumption that the pharmacokinetic profile reflects the therapeutic effectiveness of a drug. Thus these are indirect methods. The two major pharmacokinetic methods are:
The major pharmacokinetic methods are:
Plasma / blood level time profile.
o Time for peak plasma (blood) concentration (t max)
o Peak plasma drug concentration (Cmax)
o Area under the plasma drug concentration–time curve (AUC)
Urinary excretion studies.
o Cumulative amount of drug excreted in the urine (Du)
o Rate of drug excretion in the urine (dDu/dt)
o Time for maximum urinary excretion (t)
C. Other biological fluids
1.2. Pharmacodynamic methods:
IT involves direct measurement of drug effect on a (patho) physiological process as a function of time. Disadvantages of it may be high variability, difficult to measure, limited choices, less reliable, more subjective, drug response influenced by several physiological & environmental factors.
They involve determination of bioavailability from:
Acute pharmacological response.
Therapeutic response.
1.3. In-vitro dissolution studies
Closed compartment apparatus
Open compartment apparatus
Dialysis systems.
1.4. Clinical observations
Well-controlled clinical trials
Biopharmaceutics: Mechanisms of Drug AbsorptionSURYAKANTVERMA2
Biopharmaceutics is defined as the study of factors influencing the rate and amount of drug that reaches the systemic circulation and the use of this information to optimise the therapeutic efficacy of the drug products.
1. Measurement of Bioavailability:
Direct and indirect methods may be used to assess drug bioavailability. The in-vivo bioavailability of a drug product is demonstrated by the rate and extent of drug absorption, as determined by comparison of measured parameters, e.g., concentration of the active drug ingredient in the blood, cumulative urinary excretion rates, or pharmacological effects.
For drug products that are not intended to be absorbed into the bloodstream, bioavailability may be assessed by measurements intended to reflect the rate and extent to which the active ingredient or active moiety becomes available at the site of action.
The design of the bioavailability study depends on the objectives of the study, the ability to analyze the drug (and metabolites) in biological fluids, the pharmacodynamics of the drug substance, the route of drug administration, and the nature of the drug product.
Pharmacokinetic and/or pharmacodynamic parameters as well as clinical observations and in-vitro studies may be used to determine drug bioavailability from a drug product.
1.1. Pharmacokinetic methods:
These are very widely used and based upon the assumption that the pharmacokinetic profile reflects the therapeutic effectiveness of a drug. Thus these are indirect methods. The two major pharmacokinetic methods are:
The major pharmacokinetic methods are:
Plasma / blood level time profile.
o Time for peak plasma (blood) concentration (t max)
o Peak plasma drug concentration (Cmax)
o Area under the plasma drug concentration–time curve (AUC)
Urinary excretion studies.
o Cumulative amount of drug excreted in the urine (Du)
o Rate of drug excretion in the urine (dDu/dt)
o Time for maximum urinary excretion (t)
C. Other biological fluids
1.2. Pharmacodynamic methods:
IT involves direct measurement of drug effect on a (patho) physiological process as a function of time. Disadvantages of it may be high variability, difficult to measure, limited choices, less reliable, more subjective, drug response influenced by several physiological & environmental factors.
They involve determination of bioavailability from:
Acute pharmacological response.
Therapeutic response.
1.3. In-vitro dissolution studies
Closed compartment apparatus
Open compartment apparatus
Dialysis systems.
1.4. Clinical observations
Well-controlled clinical trials
'Basic mechanisms of membrane transport is the topic of general pharmacology.
Introduction- Membrane Transport
Plasma Membrane
Lipid solubility in membrane permeation
Transporters Versus Channels
Mechanisms of Transport
Passive Diffusion
Relationship between Molecular weight and Diffusion
Carrier mediated Transport
Facilitated Diffusion
Active Transport
Primary Active Transport
P type- Na+ K+-ATPase
Secondary Active transport- Symport, Antiport
Intestinal Transporters with e.g
Vesicular Transport-Exocytosis, Endocytosis-Phagocytosis,Pinocytosis
Pore (Convective) Transport
Ion Pair Formation
Drug Absorption ,m.pharm, semester 2, 1st yearManshiRana2
Drug absorption is the process of movement of unchanged drug from the site of administration to systemic circulation.
Absorption is the process of movement of unchanged drug from the site of administration to the site of measurement i.e. Plasma.
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
Honest Reviews of Tim Han LMA Course Program.pptxtimhan337
Personal development courses are widely available today, with each one promising life-changing outcomes. Tim Han’s Life Mastery Achievers (LMA) Course has drawn a lot of interest. In addition to offering my frank assessment of Success Insider’s LMA Course, this piece examines the course’s effects via a variety of Tim Han LMA course reviews and Success Insider comments.
Model Attribute Check Company Auto PropertyCeline George
In Odoo, the multi-company feature allows you to manage multiple companies within a single Odoo database instance. Each company can have its own configurations while still sharing common resources such as products, customers, and suppliers.
Embracing GenAI - A Strategic ImperativePeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
1. Dr S RAMKANTH, M. Pharm., Ph.D.,
Professor & Head, Department of Pharmaceutics
KARPAGAM COLLEGE OF PHARMACY, COIMBATROE – 32, TAMIL NADU
email id: ramkanthsg@gmail.com Cell: +919618312122
Mechanism of Drug Absorption
UNIT 1
2. 28 June 2020Dept. of Pharmaceutics, KCP, CBE - 32
2
Mechanism of Absorption
1. Transcellular / intracellular transport
A. Passive Transport Processes
I. Passive diffusion
II. Pore transport
III. Ion- pair transport
IV. Facilitated diffusion
B. Active transport processes
I. Primary
II. Secondary
a. Symport (Co-transport)
b. Antiport (Counter transport)
2. Paracellular / Intercellular Transport
A. Permeation through tight junctions of
epithelial cells
B. Persorption
3. Vesicular or Corpuscular Transport (Endocytosis)
A. Pinocytosis
B. Phagocytosis
There three broad categories are
3. 28 June 2020Dept. of Pharmaceutics, KCP, CBE - 32
3
Passive Diffusion
Also known as Non ionic Diffusion
90% of drug
Principle of Concentration gradient / Electrochemical Gradient
Diffusion
4. Passive Diffusion (Cont.)
Passive diffusion is best expressed by Fick’s first law of diffusion which states
that the drug molecules diffuse from a region of higher concentration to one of
lower concentration until equilibrium is attained and that the rate of diffusion is
directly proportional to the concentration gradient across the membrane.
𝒅𝑸
𝒅𝒕
=
𝑫𝑨𝑲 𝒎/ 𝒘
𝒉
(𝑪𝑮𝑰𝑻 − 𝑪)
dQ/dt = rate of drug diffusion
D = diffusion coefficient of the drug
A = surface area of the absorbing membrane
Km/w = partition coefficient of the drug between
membrane and the aqueous phase
(CGIT – C) = difference in the concentration of drug in GI
fluid & the plasma
h = thickness of the membrane (length)
28 June 2020Dept. of Pharmaceutics, KCP, CBE - 32
4
5. 28 June 2020Dept. of Pharmaceutics, KCP, CBE - 32
5
Passive Diffusion (Cont.)
Based on the equation, certain characteristics of passive diffusions are
Concentration Gradient – Down Hill Process
Rate of drug transfer is proportional to concentration gradient between the
GI fluid & Blood
Greater the surface area and less thickness of the membrane – Better
absorption Equilibrium will be attained upon equal concentration on both sides
Drug with Ionized / Unionized drug both approaches where Unionized drug
transfer better
Greater the membrane or water partition co-efficient, faster the absorption
Dilution of GI fluid is used in treatment of over dose or poisoning
6. 28 June 2020Dept. of Pharmaceutics, KCP, CBE - 32
6
Passive Diffusion (Cont.)
Passive diffusion is energy dependent and non saturable
It depends on square root of molecular weight of the drug
100 to 400 Da
Diffusion decreases with increase in molecular weight
Maintenance of Sink Condition
DAKm/w/h may be constant in few condition hence its replace by P in the
previous equation 𝒅𝑸
𝒅𝒕
= 𝑷 𝑪𝑮𝑰𝑻
7. Pore Transport
28 June 2020Dept. of Pharmaceutics, KCP, CBE - 32
7
It is also called as convective transport, bulk flow or filtration
The driving force is hydrostatic pressure or the osmotic differences across the
membrane
The process is important in the absorption of low molecular weight (less than
100), generally water-soluble drugs through narrow, aqueous-filled channels
ex: urea, water and sugars Chain-like or linear compounds of molecular weight up to 400 Daltons can be
absorbed by filtration. For example, the straight-chain alkanes.
Drug permeation through water-filled channels is importance in renal
excretion, removal of drug from the cerebrospinal fluid and entry of drugs into
the liver
8. Ion-Pair Transport
28 June 2020Dept. of Pharmaceutics, KCP, CBE - 32
8
Absorption of drugs like quaternary ammonium compounds (Examples are
benzalkonium chloride, benzethonium chloride) and sulphonic acids (sulfonic
acid), which ionise under all pH conditions, is ion-pair transport
Despite their low o/w partition coefficient values, such agents penetrate the
membrane by forming reversible neutral complexes with endogenous ions of
the GIT like mucin.
Such neutral complexes have both the required lipophilicity as well as
aqueous solubility for passive diffusion. Such a phenomenon is called as ion-
pair transport
10. Carrier-Mediated Transport
28 June 2020Dept. of Pharmaceutics, KCP, CBE - 32
10
Some polar drugs cross the membrane more readily than can be predicted from
their concentration gradient and partition coefficient values. Like
monosaccharides, amino acids and vitamins will be poorly absorbed
The mechanism is involved is carrier that binds reversibly or non-covalently
with the solute molecules to be transported.
This carrier-solute complex traverses across the membrane to the other side
where it dissociates and discharges the solute molecule.
The carrier then returns to its original site to complete the cycle by accepting
a fresh molecule of solute.
Carriers in membranes are proteins (transport proteins) and may be an
enzyme or some other component of the membrane
11. Carrier-Mediated Transport - Important Characteristics
28 June 2020Dept. of Pharmaceutics, KCP, CBE - 32
11
Structure Specific – False Nutrients
Competitive binding
Capacity Limited
Mixed Order Kinetics
Bioavailability of drug absoption decreased with increase in
dose
Absorption window
12. 28 June 2020Dept. of Pharmaceutics, KCP, CBE - 32
12
Carrier Mediated Transport
Two types of Carrier Mediated Transport are – Facilitated Diffusion & Active
Transport Facilitated Diffusion
It is a carrier-mediated transport system that operates down the
concentration gradient (downhill transport) but at a much a faster rate than
can be accounted by simple passive diffusion.
The driving force is concentration gradient (hence a passive process).
Since no energy expenditure is involved, the process is not inhibited by
metabolic poisons that interfere with energy production.
13. 28 June 2020Dept. of Pharmaceutics, KCP, CBE - 32
13
Active Transport Processes
This transport mechanism requires energy in the form ATP. Active transport
mechanisms are further subdivided into -
Primary active transport – In this process, there is direct ATP requirement.
Moreover, the process transfers only one ion or molecule and in only one
direction, and hence called as uniporter e.g. absorption of glucose.
Secondary active transport – In these processes, there is no direct requirement
of ATP i.e. it takes advantage of previously existing concentration gradient. The
energy required in transporting an ion aids transport of another ion or molecule
(co-transport or coupled transport) either in the same direction or in the
opposite direction.
14. 28 June 2020Dept. of Pharmaceutics, KCP, CBE - 32
14
Active Transport
Accordingly this process is further subdivided into
Symport (co-transport) – involves movement of both molecules
in the same direction e.g. Na+-glucose symporter
Antiport (counter-transport) – involves movement of molecules
in the opposite direction e.g. H+ ions using the Na+ gradient in
the kidneys.
16. 28 June 2020Dept. of Pharmaceutics, KCP, CBE - 32
16
https://www.youtube.com/watch?v=dUMNd6Eunbw
17. 28 June 2020Dept. of Pharmaceutics, KCP, CBE - 32
17
Paracellular/Intercellular Transport
It is defined as the transport of drugs through the junctions between
the GI epithelial cells. This pathway is of minor importance in drug
absorption. The two paracellular transport mechanisms involved in drug
absorption are – Permeation through tight junctions of epithelial cells – this process
basically occurs through openings which are little bigger than the
aqueous pores. Compounds such as insulin and cardiac glycosides are
taken up this mechanism Persorption – is permeation of drug through temporary openings
formed by shedding of two neighbouring epithelial cells into the lumen