K.Sailakshmi presented on degradation kinetics and mechanisms of drugs. She defined kinetics, order of reaction, and half-life. The presentation covered common degradation pathways like zero-order, first-order and second-order reactions. Mechanisms of drug degradation discussed included hydrolysis, decarboxylation, oxidation and photodegradation. Specific examples were provided to illustrate different degradation types and kinetics models. The presentation concluded that understanding degradation kinetics can provide insight into reaction mechanisms and improve product stability.
Introduction to Dissolution equipment's, Calibration of dissolution apparatus, Dissolution procedure development and validation, Dissolution method development for generic drug products.
Stability studies ensuring the maintenance of product quality, safety and efficacy throughout the shelf life are considered as pre-requisite for the acceptance and approval of any pharmaceutical product. Stability testing is a routine procedure performed on drug substances and products and is employed at various stages of the product development.
Dissolution, factors affecting drug dissolution, methods to evaluate dissolution, advantages and disadvantages, recent approaches--these are the topics covered in this presentation.
Dissolution : Official and Non official methods, Alternative methods of dissolution testing and transport models, Drug release testing, Invitro drug release testing
drug execipent compatibilty studies is of prime importance for the better formulation of the new drug and also for reducing cost by verfication of the data at the earlier atage.
this presentation will give the brief explanation of the goal, importance, dteps involve to studi the drug execient compatibility studies with different examples suitable accordiingly.
Introduction to Dissolution equipment's, Calibration of dissolution apparatus, Dissolution procedure development and validation, Dissolution method development for generic drug products.
Stability studies ensuring the maintenance of product quality, safety and efficacy throughout the shelf life are considered as pre-requisite for the acceptance and approval of any pharmaceutical product. Stability testing is a routine procedure performed on drug substances and products and is employed at various stages of the product development.
Dissolution, factors affecting drug dissolution, methods to evaluate dissolution, advantages and disadvantages, recent approaches--these are the topics covered in this presentation.
Dissolution : Official and Non official methods, Alternative methods of dissolution testing and transport models, Drug release testing, Invitro drug release testing
drug execipent compatibilty studies is of prime importance for the better formulation of the new drug and also for reducing cost by verfication of the data at the earlier atage.
this presentation will give the brief explanation of the goal, importance, dteps involve to studi the drug execient compatibility studies with different examples suitable accordiingly.
Evaluation methods for drug excipients and container interactionSagar Savale
Excipients are one of the three components that in combination produce the medicine that the patient will take.
In therapeutic terms, the API is of primary importance because without it there is no treatment and no product.
In term of drug manufacturing all three of them are equally important so we cannot neglect anyone of them.
The interactions between excipients and the other two components (the API and the manufacturing process), and/or between two or more excipients, are fundamental to the transformation of an API into a medicinal product.
Physics of Tablet compression is very useful during study of the tablet. It contains the mechanism of tablet compression. It also contains the process of tablet compression.
GCE A LEVEL TOPIC: (A2) CHEMICAL KINETICS
PLEASE DOWNLOAD BECAUSE THERE ARE MANY ANIMATIONS THAT HIDE SOME OF THE CONTENTS (THE ANIMATIONS DO NOT PLAY DURING THE PREVIEW)
Evaluation methods for drug excipients and container interactionSagar Savale
Excipients are one of the three components that in combination produce the medicine that the patient will take.
In therapeutic terms, the API is of primary importance because without it there is no treatment and no product.
In term of drug manufacturing all three of them are equally important so we cannot neglect anyone of them.
The interactions between excipients and the other two components (the API and the manufacturing process), and/or between two or more excipients, are fundamental to the transformation of an API into a medicinal product.
Physics of Tablet compression is very useful during study of the tablet. It contains the mechanism of tablet compression. It also contains the process of tablet compression.
GCE A LEVEL TOPIC: (A2) CHEMICAL KINETICS
PLEASE DOWNLOAD BECAUSE THERE ARE MANY ANIMATIONS THAT HIDE SOME OF THE CONTENTS (THE ANIMATIONS DO NOT PLAY DURING THE PREVIEW)
This presentation discusses the various uses of chemical kinetics involved in the unit processes involved in most of the industries these days. I have discussed all the basics and also included 4 examples with detailed description.
Rate of reaction,Order of Reaction,Molecularity of Reaction,Zero Order Reactions,First Order Reactions, Half life of reactuion ,Sequential Reactions,Arrhenius Equation,Temperature Coefficient,Collision Theory of Reaction Rate,Radioactivity
Pharmaceutical formulation is the means whereby a drug is converted into a medicine, i.e., to a suitable form for administration to a patient by a particular route.
The conversion of a drug into a medicine often involves the addition of pharmaceutical adjuvants (excipients) such as binding agents, disintegrating agents, antioxidants, antimicrobial preservative and emulsifying agents etc.
The stability of a medicine relates to the various changes that may occur in the medicine during preparation and storage and to the impact of those changes on its fitness for use.
The all the content in this profile is completed by the teachers, students as well as other health care peoples.
thank you, all the respected peoples, for giving the information to complete this presentation.
this information is free to use by anyone.
free for all download and learn it
it is in original ppt format for you my friends
Definition: Chemical conversion of one form to another.
The term is used synonymously with METABOLISM.
Drug biotransformation is thus a DETOXIFICATION process.
Liver is the primary site for metabolism of almost all drugs.
The decreasing order of drug metabolising ability of various organs is :
Liver > Lungs > Kidneys > Intestine > Placenta > Adrenals > Skin
Brain, testes, muscles, spleen, etc also metabolise drugs but to a small extent
ARTIFICIAL INTELLIGENCE IN HEALTHCARE.pdfAnujkumaranit
Artificial intelligence (AI) refers to the simulation of human intelligence processes by machines, especially computer systems. It encompasses tasks such as learning, reasoning, problem-solving, perception, and language understanding. AI technologies are revolutionizing various fields, from healthcare to finance, by enabling machines to perform tasks that typically require human intelligence.
Anti ulcer drugs and their Advance pharmacology ||
Anti-ulcer drugs are medications used to prevent and treat ulcers in the stomach and upper part of the small intestine (duodenal ulcers). These ulcers are often caused by an imbalance between stomach acid and the mucosal lining, which protects the stomach lining.
||Scope: Overview of various classes of anti-ulcer drugs, their mechanisms of action, indications, side effects, and clinical considerations.
- Video recording of this lecture in English language: https://youtu.be/lK81BzxMqdo
- Video recording of this lecture in Arabic language: https://youtu.be/Ve4P0COk9OI
- Link to download the book free: https://nephrotube.blogspot.com/p/nephrotube-nephrology-books.html
- Link to NephroTube website: www.NephroTube.com
- Link to NephroTube social media accounts: https://nephrotube.blogspot.com/p/join-nephrotube-on-social-media.html
Tom Selleck Health: A Comprehensive Look at the Iconic Actor’s Wellness Journeygreendigital
Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
Follow us on: Pinterest
Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
Explore natural remedies for syphilis treatment in Singapore. Discover alternative therapies, herbal remedies, and lifestyle changes that may complement conventional treatments. Learn about holistic approaches to managing syphilis symptoms and supporting overall health.
Title: Sense of Taste
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
micro teaching on communication m.sc nursing.pdfAnurag Sharma
Microteaching is a unique model of practice teaching. It is a viable instrument for the. desired change in the teaching behavior or the behavior potential which, in specified types of real. classroom situations, tends to facilitate the achievement of specified types of objectives.
Pulmonary Thromboembolism - etilogy, types, medical- Surgical and nursing man...VarunMahajani
Disruption of blood supply to lung alveoli due to blockage of one or more pulmonary blood vessels is called as Pulmonary thromboembolism. In this presentation we will discuss its causes, types and its management in depth.
Flu Vaccine Alert in Bangalore Karnatakaaddon Scans
As flu season approaches, health officials in Bangalore, Karnataka, are urging residents to get their flu vaccinations. The seasonal flu, while common, can lead to severe health complications, particularly for vulnerable populations such as young children, the elderly, and those with underlying health conditions.
Dr. Vidisha Kumari, a leading epidemiologist in Bangalore, emphasizes the importance of getting vaccinated. "The flu vaccine is our best defense against the influenza virus. It not only protects individuals but also helps prevent the spread of the virus in our communities," he says.
This year, the flu season is expected to coincide with a potential increase in other respiratory illnesses. The Karnataka Health Department has launched an awareness campaign highlighting the significance of flu vaccinations. They have set up multiple vaccination centers across Bangalore, making it convenient for residents to receive their shots.
To encourage widespread vaccination, the government is also collaborating with local schools, workplaces, and community centers to facilitate vaccination drives. Special attention is being given to ensuring that the vaccine is accessible to all, including marginalized communities who may have limited access to healthcare.
Residents are reminded that the flu vaccine is safe and effective. Common side effects are mild and may include soreness at the injection site, mild fever, or muscle aches. These side effects are generally short-lived and far less severe than the flu itself.
Healthcare providers are also stressing the importance of continuing COVID-19 precautions. Wearing masks, practicing good hand hygiene, and maintaining social distancing are still crucial, especially in crowded places.
Protect yourself and your loved ones by getting vaccinated. Together, we can help keep Bangalore healthy and safe this flu season. For more information on vaccination centers and schedules, residents can visit the Karnataka Health Department’s official website or follow their social media pages.
Stay informed, stay safe, and get your flu shot today!
Ethanol (CH3CH2OH), or beverage alcohol, is a two-carbon alcohol
that is rapidly distributed in the body and brain. Ethanol alters many
neurochemical systems and has rewarding and addictive properties. It
is the oldest recreational drug and likely contributes to more morbidity,
mortality, and public health costs than all illicit drugs combined. The
5th edition of the Diagnostic and Statistical Manual of Mental Disorders
(DSM-5) integrates alcohol abuse and alcohol dependence into a single
disorder called alcohol use disorder (AUD), with mild, moderate,
and severe subclassifications (American Psychiatric Association, 2013).
In the DSM-5, all types of substance abuse and dependence have been
combined into a single substance use disorder (SUD) on a continuum
from mild to severe. A diagnosis of AUD requires that at least two of
the 11 DSM-5 behaviors be present within a 12-month period (mild
AUD: 2–3 criteria; moderate AUD: 4–5 criteria; severe AUD: 6–11 criteria).
The four main behavioral effects of AUD are impaired control over
drinking, negative social consequences, risky use, and altered physiological
effects (tolerance, withdrawal). This chapter presents an overview
of the prevalence and harmful consequences of AUD in the U.S.,
the systemic nature of the disease, neurocircuitry and stages of AUD,
comorbidities, fetal alcohol spectrum disorders, genetic risk factors, and
pharmacotherapies for AUD.
Lung Cancer: Artificial Intelligence, Synergetics, Complex System Analysis, S...Oleg Kshivets
RESULTS: Overall life span (LS) was 2252.1±1742.5 days and cumulative 5-year survival (5YS) reached 73.2%, 10 years – 64.8%, 20 years – 42.5%. 513 LCP lived more than 5 years (LS=3124.6±1525.6 days), 148 LCP – more than 10 years (LS=5054.4±1504.1 days).199 LCP died because of LC (LS=562.7±374.5 days). 5YS of LCP after bi/lobectomies was significantly superior in comparison with LCP after pneumonectomies (78.1% vs.63.7%, P=0.00001 by log-rank test). AT significantly improved 5YS (66.3% vs. 34.8%) (P=0.00000 by log-rank test) only for LCP with N1-2. Cox modeling displayed that 5YS of LCP significantly depended on: phase transition (PT) early-invasive LC in terms of synergetics, PT N0—N12, cell ratio factors (ratio between cancer cells- CC and blood cells subpopulations), G1-3, histology, glucose, AT, blood cell circuit, prothrombin index, heparin tolerance, recalcification time (P=0.000-0.038). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and PT early-invasive LC (rank=1), PT N0—N12 (rank=2), thrombocytes/CC (3), erythrocytes/CC (4), eosinophils/CC (5), healthy cells/CC (6), lymphocytes/CC (7), segmented neutrophils/CC (8), stick neutrophils/CC (9), monocytes/CC (10); leucocytes/CC (11). Correct prediction of 5YS was 100% by neural networks computing (area under ROC curve=1.0; error=0.0).
CONCLUSIONS: 5YS of LCP after radical procedures significantly depended on: 1) PT early-invasive cancer; 2) PT N0--N12; 3) cell ratio factors; 4) blood cell circuit; 5) biochemical factors; 6) hemostasis system; 7) AT; 8) LC characteristics; 9) LC cell dynamics; 10) surgery type: lobectomy/pneumonectomy; 11) anthropometric data. Optimal diagnosis and treatment strategies for LC are: 1) screening and early detection of LC; 2) availability of experienced thoracic surgeons because of complexity of radical procedures; 3) aggressive en block surgery and adequate lymph node dissection for completeness; 4) precise prediction; 5) adjuvant chemoimmunoradiotherapy for LCP with unfavorable prognosis.
Lung Cancer: Artificial Intelligence, Synergetics, Complex System Analysis, S...
Degradation Kinetics and mechanisam
1. 1
PRESENTATION
ON
DEGRADATION KINECTICS AND MECHANISM
BY,
NAME : K.SAILAKSHMI,
ROLL NO : 256213886016,
,
DEPARTMENT: M.PHARMACY(PHARMACEUTICS).
UNDER THE GUIDENCE,
OF
Mrs.YASMIN BEGUM
M.pharmacy.
3. 3
Definitions:-
Kinetics:
DEGRADATION KINETICS
pharmacokinetics is the mathematical analysis of process of ADME
Rate of reaction:
The rate of a reaction can be expressed either decrease or
Increase in concentration per unit time
dx/dt
Order of reaction:
order of reaction express expermentally determined dependence
of rate upon reactant concentration.
dc/dt = - kc n
Where,K = rate constant, n = order of reaction(0,1,2)
Half life:
It is defined as the time taken for 50% of the reaction to occur.
This time is called the half life of the reaction.(t 1/2).
4. 4
DEGRADATION KINETICS PATHWAYS
The degradation of kinetics mathematically divided as follows:
Zero order reactions
First order reactions
Second order reactions
Third order reactions
5. 5
ZERO ORDER REACTION
A zero-order reaction has a rate that is independent of the concentration of the
reactant(s).
dc/dt = -ko
Where,
ko = zero order rate constant (mg/ml)
dc = -k0dt
By integrating,
c-co = -kot
Where,
co = conc. Of drug at t=0
c = conc. Of drug at to under go reaction at time t.
7. 7
Half life of zero – order reaction:
When t = t ½ , c = c0/2
There fore,
co/2 = co – ko t1/2
t ½ = co/2k0
Thus,
t1/2 of zero order is constant by proportional to initial conc.
Of drug co & inversely to zero order rate constant ko.
8. 8
EXAMPLE:
Decomposition of NH3 in presence of molybdenum or tungsten is
a zero-order reaction. [Mo]
2NH3 → N2 + 3H2
The surface of the catalyst is almost completely covered by
NH3 molecules. The adsorption of gas on the surface cannot change by
the pressure or concentration of NH3. Thus, the concentration of gas
phase remains constant although the product is formed.Therefore, this
reaction zero order kinetics.
11. 11
FIRST ORDER REACTION
A reaction is said to be first order if its rate is determined by the change of one
concentration term only.
dc/dt = - kdt
By integrating,
ln c =ln co-kt
c = coe-kt
Since ln = 2.303log
Log c =log c0 – kt/2.303
k = 2.303/t log c/c0
13. 13
Half life of first order reaction:
If c = c0/2 at t1/2
t1/2 = 0.693/k
Examples of first order reactions
1. Decomposition of H2O2 in aqueous solution
H2O2 → H2O + 1/2 O2
2.Hydrolysis of methyl acetate in presence of mineral acids.
Acid
CH3COOCH3 + H2O → CH3COOH + CH3OH
14. 14
PSEUDO FIRST ORDER REACTION
This occurs when the rate of process is proportional to the concentration of
only one reactant even though the reaction involves several reactant species
EXAMPLE:
Procaine hydrochloride undergo hydrolysis obeys pseudo first order reaction.
15. 15
SECOND ORDER REACTION:
A reaction is said to be of second order if its reaction rate is determined by
the variation of two concentration terms.
The kinetics of second order reactions are given as follows:
(i) When concentration of both reactants are equal or two molecules of the
same reactant are involved in the change, i.e.,
A + B → products
or 2A → products
dx/dt = k(a(a-x)3
On solving this equation,
k = 1/t.x/a(a-x)
where a = initial concentration of the reactant or reactants and
x = concentration of the reactant changed in time t.
16. 16
(ii) When the initial concentrations of the two reactants are different,
i.e.,
A + B → products
Initial conc. a b
dx/dt = k(a-x)(b-x)
k = 2.303/t(a-b) log10 b(a-x)/a(b-x)
(a-x) and (b-x) are the concentrations of A and B after time interval, t.
Half life of second order reaction:
t1/2 = 1/ka
Examples of second order reactions
Hydrolysis of ester by an alkali (saponification).
CH3COOC2H5 + NaOH → CH3COONa + C2H5OH
17. 17
THIRD ORDER REACTIONS
A reaction is said to be of third order if its rate is determined by the variation
of three concentration terms.
When the concentration of all the three
reactants is same or three molecules of the same reactant are involved, the
rate expression is given as
3A → products
A + B + C → products
dx/dt = k(a-x)3
On solving this equation,
k = 1/t.x(2a-x)/(2a2 (a-x)2)
Examples of third order reacting
1. Reacting between nitric oxide and oxygen
2NO + O2 → 2NO2
2. Reaction between nitric oxide and chlorine.
2NO + Cl2 → 2NOCl
18. 18
DRUG DEGRADATION MECHANISMS
TYPES OF DRUG DEGRADATION
CHEMICAL DEGRADATION
○ HYDROLYSIS ESTER AMIDES BARBITURATES, HYDANOINS
& IMIDES SCHIFF BASE AND OTHER REACTION INVOLVING
CARBON NITROGEN BOND CLEAVAGE
○ DEHYDRATION
○ ISOMERIZATION & RACEMIZATION
○ DECARBOXYLATION & ELIMINATION
○ OXIDATION
○ PHOTODEGRADATION
19. 19
R1
O
X + H2O R1
O
OH
+ HX
Carboxylic acid derivatives
20. 20
ESTER HYDROLYSIS
• Ester hydrolysis is a chemical degradative process during which
the ester group reacts with water and yields an acid and an alcohol.
• It occurs because of the disruption of covalent linkage between carbon
and oxygen atom
Examples:
drugs like aspirin, cocaine, procaine
21. 21
AMIDES HYDROLYSIS
Amide bonds are commonly found in drug molecules.
•Amide bonds are less susceptible to hydrolysis than ester bonds
because the carbonyl carbon of the amide bond is less electrophilic
(the carbon-to-nitrogen bond has considerable double bond
character)
• The leaving group, an amine, is a poorer leaving
EXAMPLES
.
• Acetaminophen, chloramphenicol,lincomycin, indomethacin and
sulfacetamide, all of which are known to produce an amine and an acid
through hydrolysis of their amide bonds.
.
22. 22
• β-Lactam antibiotics such as penicillins and cephalosporins, which
are cyclic amides or lactams, undergo rapid ring opening due to
hydrolysis
23. 23
BARBITURATES, HYDANTOINS & IMIDES
• Barbiturates, hydantoins, and imides contain functional groups related to amides
but tend to be more reactive.
• Barbituric acids such as barbital, phenobarbital and amobarbital, undergo ring-opening
hydrolysis.
• Decomposition products formed from these drug substances are susceptible to
further decomposition reactions such as decarboxylation.
24. SCHIFF BASE AND OTHER REACTION INVOLVING
CARBON NITROGEN BOND CLEAVAGE
• Benzodiazepines such as diazepam,oxazepam, and nitrazepam undergo ring
opening due to reversible hydrolysis of the amide and azomethine bonds
• Benzodiazepinoxazoles(oxazole-condensed benzodiazepines) such as
oxazolam,flutazolam, haloxazolam, and cloxazolam are not Schiff bases but
undergo ring opening due to hydrolysis.
24
25. 25
DEHYDRATION
○ Sugars such as glucose and lactose are known to undergo
dehydration to form 5- (hydroxymethyl)furural.
○ Erythromycin is susceptible to acidcatalyzed dehydration.
○ prostaglandins E1 and E2 undergo dehydration followed by
isomerization.
○ Batanopride undergoes an intramolecular ring- closure reaction in the
acidic pH range due to dehydration whereas streptovitacin A exhibits
two successive acid-catalyzed dehydration reactions,.
Lactose/glucose 5-(hydroxymethyl furfural)
MILLARD REACTION
26. ISOMERIZATION
○ Isomerisation is the process by which one molecule is transformed into
another molecule which has exactly the same atoms, but the atoms are
rearranged e.g. A-B-C → B-A-C
○ Pilocarpine undergoes epimerization by base catalysis.
○ Tetracyclines such as rolitetracycline and ergotamine exhibit epimerization
by acid catalysis.
○ Etoposide converts reversibly to picroetoposide, a cis- lactone, and then
hydrolyzes to cis-hydroxy acid in the alkaline pH region.
26
27. 27
RACEMIZATION
• Racemization refers to partial conversion of one enantiomer into
another.
• Epinephrine is oxidized and undergoes racemization under strongly
acidic conditions.
28. 28
DECARBOXYLATION
• Drug substances having a carboxylic acid group are sometimes
susceptible to decarboxylation,
• 4-Aminosalicylic acid is a good example.
• Foscarnet also undergoes decarboxylation under strongly acidic
conditions.
29. 29
ELIMINATION
• In elimination reaction reaction some groups of the substance
is eliminated.
• Trimelamol eliminates its hydroxymethyl groups and forms
formaldehyde.
• Levothyroxine eliminates iodine.
30. 30
OXIDATION
• Oxidation mechanisms for drug substances
depend on the chemical structure of the drug and
the presence of reactive oxygen species or other
oxidants.
• Catechols such as methyldopa and epinephrine
are readily oxidized to quinones.
N
R2
H
R1
O O R1
HO N
R2
R1
N
R2
O O R1
N+ O-
R2
Amines
31. PHOTODEGRADATION
• Photodegradation is the process by which light- sensitive drugs or excipient
molecules are chemically degraded by light, room light or sunlight.
31
The variation of degradation depends on the wavelength of light, shorter
wavelengths because more damage than longer wavelengths.
Before a photodegradation reaction can occur, the energy from light
radiation must be absorbed by the molecules.
Photodegradation of the chloroquine and primaquine gives the various
product through different pathways.
32. 32
Two way in which photodegradation can occur are:
The light energy absorbed must be sufficient to achieve the activation energy
Or
The light energy absorbed by molecules is passed on to other molecules which
allow degradation to take place
33. 33
REACTION OF AMINES WITH
REDUCING SUGARS
• Reducing sugars readily react with primary
amines, including those of amino acids, through
the Maillard reaction.
• Drug substances with primary or secondary
amine groups undergo this
addition/rearrangement reaction, also called
the .browning. reaction because of the resulting
discoloration.
Examples are the reaction of amphetamine,isoniazid dextroamphetamine
sulfate and norphenylephrine with sugars such as lactose and the degradation
products of sugars, such as 5-(hydroxymethyl)furfural.
• Sulpyrine forms ann addition product with glucose
34. 34
CONCLUSION
•Kinetics allows chemists to predict how the speed of a reaction will
change under different reaction conditions.
•The study of kinetics is important because it can elucidate information
about the mechanism of a reaction and can also allow chemists to be
more efficient in the laboratory.
•It also help full to improve the product stability.