Section 13.2 Drugs (Book 3B, Chapter 36) - PowerPoint PPT Presentation

Loading...

PPT – Section 13.2 Drugs (Book 3B, Chapter 36) PowerPoint presentation | free to download - id: 44bc7a-ZGZmN



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

Section 13.2 Drugs (Book 3B, Chapter 36)

Description:

Chiral drugs What drugs in our daily life are chiral? What drugs in our daily life are chiral? What drugs in our daily life are chiral? – PowerPoint PPT presentation

Number of Views:177
Avg rating:3.0/5.0
Slides: 104
Provided by: Windo425
Learn more at: http://edblog.hkedcity.net
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Section 13.2 Drugs (Book 3B, Chapter 36)


1
Section 13.2 Drugs(Book 3B, Chapter 36)
2
Syllabus for consideration
3
Syllabus for consideration (12.6)
4
overview
  • Drugs and medicine an introduction
  • Key stages of drug development
  • Some common drugs
  • Dangerous drugs
  • Chiral drugs

5
overview
  • Drugs and medicine an introduction
  • Key stages of drug development
  • Some common drugs
  • Dangerous drugs
  • Chiral drugs

6
Drugs and medicine
  • Drugs chemical substances producing
    physiological effects on human body
  • Often act by altering a range of biological
    processes
  • Carefully researched, monitored by doctors or
    pharmacists or else extremely hazardous
  • Medicine Drugs prescribed by doctors
  • Poisons if drugs taken abusively excessive
    intake death (e.g. excessive paracetamol (a
    painkiller,???????) coma or death)

7
Drugs and medicine
  • Most drugs are natural products modified by
    chemical reactions or are synthetic chemical
    substances.
  • Categorized according to their use
  • Painkillers (???)
  • Antacids (???)
  • Antibiotics (???)
  • Cancer drugs (???) etc.
  • Categorized according to their biological
    effects
  • Narcotics (???)
  • Analgesics (???)
  • Hallucinogens (???)
  • Depressants (???)
  • Stimulants (???)
  • Tranquillizers (???)etc.

8
Drugs and medicine (3B 194 196)
  • In ancient times, drugs discovery related to
    finding of natural products showing medicinal
    effects
  • From extracts of animals, plants and even
    minerals
  • Nowadays, drug development is a systematic
    process including stages of
  • Lead compound discovery (???????)
  • Molecular structural modeling (????)
  • Dosage formulation (????)
  • Safety tests and trials (?????????)
  • Approval from government monitoring agency (????)
  • Two examples aspirin (????) and cisplatin (??)

9
overview
  • Drugs and medicine an introduction
  • Key stages of drug development
  • Some common drugs
  • Dangerous drugs
  • Chiral drugs

10
Key stages of drug development
  • Aspirin
  • Cis-platin

11
Key stages of drug development
  • Aspirin (Book 3B, p.191 p.192)
  • Cis-platin

12
Key stages of aspirin developmentLead compound
discovery
  • Aspirin development originated from discovery of
    medicinal use of the bark of the willow tree (??)
    240 years ago
  • In 1827, a Scottish physician used extracts to
    treat acute rheumatism (???)
  • Active ingredient found to be salicin (???)
    (isolated from willow bark and flowers of
    meadowsweet (??????) plant)

13
Key stages of aspirin developmentMolecular
modiFication)
  • 1870, Prof von Nencki discovered salicin was
    converted to salicylic acid (???) in the body.
  • Synthesis of salicylic acid and prescribed to
    cure fevers
  • BUT salicylic acid causes serious burns and
    irritation to oral cavity, oesophagus and
    stomach.
  • ? patients taking salicylic acid ulcers (??)

14
Key stages of aspirin developmentmolecular
modification
  • Reduce side effect, use sodium hydroxide to
    neutralize carboxylic acid group
  • i.e. use sodium salicylate instead
  • This salt derivative works as an antipyretic
    (???) and the irritation (??) is reduced.

15
Key stages of aspirin developmentmolecular
formulation
  • BUT sodium salicylate tastes awful and the
    patient would vomit badly if a large dose is
    taken.
  • 1897 Felix Hofmann from Bayer synthesized a new
    compound by acetylation of the phenol group
    producing acetyl salicylic acid (or ASA).
  • ASA a mild irritant, a reasonable taste, good
    fever-reducing and pain relieving properties

16
Key stages of drug development dosage
formulation
  • ASA large scale synthesis
  • Initially as a powder in packers and later made
    into tablets
  • Today ASA formulations include additives like
    buffers.

17
Key stages of aspirin development safety tests
and human trials
  • Two stages
  • Preclinical trial
  • Clinical trial
  • Preclinical trials
  • On tissue samples and live animals
  • Provide useful information on the drugs
    absorption, distribution (transportation inside
    the body), metabolism and elimination in the
    body.
  • Clinical trial
  • Involve human testing
  • Ethical and legal issues
  • To be conducted under stringent legal approval by
    a recognized ethical committee
  • If pass all the trials certificates

18
Key stages of aspirin development market approval
  • Aspirin synthesized and marketed by Bayer
    Company
  • Initially as a powder than as a 500 mg tablet
  • One of the first drugs in the world to be
    available in a standardized dosage.

19
Key stages of drug development
  • Aspirin
  • Cis-platin (3B, p.193)

20
Key stages of cis-platin developmentLead
compound discovery
  • Discovered accidentally in 1961 by a biophysicist
    (Prof Barnett Rosenberg)
  • Studying effect of electromagnetic radiation on
    the growth of E.coli.
  • After the experiment, bacteria growth inhibited
    by electrolysis product of the Pt electrodes.
  • Rosenberg Growth of E. coli. Was inhibited by a
    square planar complex, cisplatin
    (cis-dichlorodiamineplatinum(II)) and light
  • Further investigated by other chemists

21
Key stages of cis-platin development lead
compound discovery
  • Rosenberg use of cis-platin in animal tests in
    1968
  • Cis-platin
  • capable of stopping the rapid cell division in
    bacteria at concentrations that are effective yet
    without significant toxicity.
  • Reduce the size of cancerous tumors in mice
  • Cisplatin use in anti-cancer treatment

22
Key stages of cis-platin developmentmolecular
modification
  • Rosenberg noticed that the trans isomer is
    thermodynamically more stable, it is a much less
    active complex for cancer treatment
  • Other chemical derivatives (change its ligands)
    potent anti-tumor variants of cis-platin

23
Key stages of cis-platin development molecular
modification
  • Common features in cis-platin and its
    derivatives
  • Geometries (all square planar)
  • All electrically neutral
  • Two cis-monodentate ligands or a bidentate ligand
  • Cyclic ligands can enhance the antitumor
    activities of the complexes BUT the solubility of
    complex would be decreased

24
Key stages of cis-platin development dosage
formulation
  • Serious difficulties in formulation
  • Side effects
  • Nausea (????)
  • Vomiting (??)
  • Renal failure (???)

25
Key stage of cis-platin development safety test
and human trials
  • In vivo studies (????) almost discontinued due
    to the toxicity
  • Clinical trial
  • Cvitkovic and coworkers aggressive diuresis
    (????) in minimizing renal damage
  • Gralla et al. using antiemetic drugs (???)
    resolving nausea and vomiting problems

26
Key stages of cis-platin developmentmarket
approval
  • Administered in a chloride containing solution
  • Side effects several drugs taken together
  • Mannitol (???) increase urine flow (deal with
    renal failure)
  • Injecting anti-emetics (???) minimize nausea and
    vomiting
  • Since 1970s, treat various cancers
  • Ovarian
  • Testicular
  • Lung

27
overview
  • Drugs and medicine an introduction
  • Key stages of drug development
  • Some common drugs
  • Dangerous drugs
  • Chiral drugs

28
Over-the-counter drugs and prescription drugs
(3B, p.197)
  • Over-the-counter drugs
  • Aspirin
  • Acetaminophen
  • Vitamin C
  • Prescription drugs
  • Albuterol
  • Amlodipine
  • Loratadine
  • Amoxicillin
  • Omeprazole

29
Over-the-counter drugs
  • Aspirin

30
Over-the-counter drugs
  • Analysis of aspirin
  • (See handout)

31
Over-the-counter drugs
  • Acetaminophen (paracetamol, p-acetaminophenol)
  • An analgesic that relieves pains such as
    headaches
  • Less corrosive to stomach and is an alternative
    to aspirin
  • Present in Panadol, Saridon, Tylenol and Fortolin

32
Over-the-counter drugs
  • Vitamin C (Ascorbic acid)

33
Common names of prescription drugs (3B, p.198)
34
Common names of drugs use common names for
easier reference (3B, p.198)
  • Albuterol (???)
  • Asthma medicine (???)

35
Common names of drugs use common names for
easier reference (3B, p.198)
  • Amlodipine (????)
  • Reduces blood pressure
  • Peripheral arterial vascodilator (??????????)

36
Common names of drugs use common names for
easier reference (3B, p.198)
  • Prilosec (Omeprazole,????)
  • Treatment of heartburn, stomach ulcers

37
Common names of drugs use common names for
easier reference (3B, p.198)
  • Loratadine (????)
  • Antihistamine (????)

38
Common names of drugs use common names for
easier reference (3B, p.198)
  • Amoxicillin (???????????)
  • Antibiotic (???)

39
overview
  • Drugs and medicine an introduction
  • Key stages of drug development
  • Some common drugs
  • Dangerous drugs
  • Chiral drugs

40
Dangerous drugs
  • Narcotic drugs
  • Morphine and heroin
  • Stimulant drugs
  • Ketamine, methamphetamine and phenylethylamine

41
Dangerous drugs
  • Narcotic drugs
  • Morphine and heroin
  • Stimulant drugs
  • Ketamine, methamphetamine and phenylethylamine

42
Dangerous drugs Narcotic drugs (????)
  • Chemical substances relieving pain by numbing the
    senses, inducing sleep
  • Highly addictive
  • Many countries ban their imports manufacture or
    possession
  • Commonly abused narcotic drugs
  • Morphine (??)
  • Heroin (???)

43
Dangerous drugs Narcotic drugs(3B, p.199)
  • Opium (??) and morphine (??)
  • From opium puppy (??)
  • A mixture of alkaloids,?????(organic bases)
  • Most abundant alkaloid morphine (10 opium)

44
Dangerous drugs narcotic drugs
  • Morphine and its analogues most effective
    painkillers BUT strong addiction
  • Codeine (???) less addictive while less
    pain-killing
  • Replacing the hydroxyl group by methoxy group

45
Dangerous drugs narcotic drugs
  • Heroin (3B, p.199)
  • Two hydroxyl groups replaced by two acetoxy
    groups
  • More powerful narcotic BUT more addictive

46
Danerous drugs Heroin
  • Precursor chemicals
  • Acetic anhydride (CH3 C O CCH3)

  • O O
  • Acetyl bromide (CH3COBr)
  • Acetyl chloride (CH3COCl)
  • Acetone ((CH3COCH3)
  • Ethyl ether (CH3CH2OCH2CH3)

47
Methadone (???)
http//en.wikipedia.org/wiki/Methadone accessed
on 28/12/2007
48
Comparing structures of heroin and methadone
Heroin
49
Cannabis (??)
  • Contains Cannabinoids Some examples

http//en.wikipedia.org/wiki/Cannabinoids
accessed on 28/12/2007
50
Cannabis
51
Dangerous drugs narcotic drugs(3B, p.200)
  • Adverse effects (????) of narcotics
  • Dependence (??)
  • Respiratory depression (????)
  • Drowsiness (????)
  • Death in high dosages
  • Severe withdrawal symptoms????(cramps??,
    sweating??, running nose???and tearing)
  • Illegal in trafficking and possession in many
    countries

52
Dangerous drugs
  • Narcotic drugs
  • Morphine and heroin
  • Stimulant drugs
  • Ketamine, methamphetamine and phenylethylamine

53
Dangerous drugs stimulant drugs (?????)
  • Chemicals causing an increase of alertness and
    physical awareness (???????????????) in the body
  • Often addictive
  • Increase pulse rate and respiratory rate
  • Addicts of stimulants indulge (??) in the
    temporary feeling of a boost of energy (????????)
    brought on by the drug
  • To counter the effect of depressants???(e.g.
    sleeping pills???)

54
Dangerous drugs stimulant drugs
  • Ketamine (???) (3B, p.201)
  • A stimulant patented (??) in 1963
  • A general anesthetic (???) if properly prescribed
  • Dream-like feelings hallucinations(??), deliria
    (????)
  • Also named Ketalar K?

55
Dangerous drugs stimulant drugs
  • Ketamine (???)

56
Dangerous drugs stimulant drugs
  • Ecstasy (MDMA, ?? Fing Tau Pills)

http//www.3dchem.com/molecules.asp?ID60
accessed on 28/12/2007
57
Dangerous drus ecstasy
  • Precursor chemicals
  • Safrole (???)
  • Isosafrole
  • Piperonal
  • 3,4-Methylenedioxy-phenyl-2-propanone

http//www.chemblink.com/products/94-59-7.htm
accessed on 28/12/2007
http//potency.lbl.gov/chempages/ISOSAFROLE.html
accessed on 28/12/2007
http//www.inchem.org/documents/jecfa/jecmono/v44a
je32.htm accessed on 28/12/2007
http//www.isomerdesign.com/Cdsa/scheduleUN.php?sc
hedule3sectionALLstructureC accessed on
28/12/2007
58
Dangerous drugs LSD ???
  • Lysergic acid diethylamide (LSD)

http//en.wikipedia.org/wiki/LSD accessed on
28/12/2007
59
Dangerous drugs lsd
http//www.isomerdesign.com/Cdsa/scheduleUN.php?sc
hedule3sectionALLstructureC accessed on
28/12/2007
  • Precursor chemicals
  • Ergotamine Ergometrine
    Lysergic acid

60
Dangerous drugs stimulant drugs
  • Methamphetamine (??????)
  • A member of amphetamine ???? family
  • Causes a release of dopamine ??? and
    noradrenaline ?????? from the CNS
  • Feelings of arousal ????, euphoria ??, strength
    ????, self-assertion ??, enhanced motivation ????
    and focus ???, diminished need for sleeping or
    eating
  • Last for many hours as amphetamine is not readily
    broken down by body

61
Dangerous drugs stimulant drugs
  • Methamphetamine
  • After-effects (???)
  • Lows of intense mental depression (????)
  • Fatigue (??)
  • due to the depletion of dopamine
  • An illegal drug
  • Common names speed ?????, chalk ????
  • Also known as ice ??? as methamphetamine
    hydrochloride in form of clear chunky????crystals

62
Dangerous drugs stimulant drugs
  • Methamphetamine (3B, p.202)

63
Dangerous drugs Amphetamine-type stimulant
http//www.isomerdesign.com/Cdsa/scheduleUN.php?sc
hedule3sectionALLstructureC accessed on
28/12/2007
  • Precursor chemicals
  • Ephedrine Pseudoepherdrine 1-phenyl-2-
  • propanone
  • Phenylacetic acid Norephedrine

64
Dangerous drugs stimulant drugs
  • Phenylethylamine (????) (3B, p.202)
  • Resembles amphetamines
  • Increase blood glucose level and blood pressure
    to enhance alertness and a sense of well being
    and contentment (???????)
  • Prescribed to treat narcolepsy (???)
  • Found in chocolates
  • High dosage a physiological effect similar to
    ketamine

65
Dangerous drugs stimulant drugs
  • Phenylethylamine (????)

66
Dangerous drugs stimulant drugs
  • Ketamine and methamphetamine illegal stimulants
    in HK
  • Adverse effect (3B, p.203)
  • Prolonged abuse will cause
  • Insomnia (??)
  • Depression (??)
  • Loss of appetite (????)
  • Eventually
  • Heart and kidney failure (???????)

67
Other dangerous drugs Mandrax (Methaqualone ??,
??? )
  • sedative hypnotic drug

http//www.indopedia.org/Methaqualone.html
accessed on 28/12/2007
http//www.indopedia.org/Methaqualone.html
accessed on 28/12/2007
68
Other dangerous drugs Mandrax (Methaqualone)
http//www.isomerdesign.com/Cdsa/scheduleUN.php?sc
hedule3sectionALLstructureC accessed on
28/12/2007
  • Precursor chemicals
  • Anthranilic acid
  • N-acetylanthranilicacid

69
Other dangerous chemicals angel dust
(Phencyclidine, PCP Tenocyclidine, TCP)
  • Originally used as anaesthetic (??)
  • Exhibits a hallucinogenic (??) effect

http//en.wikipedia.org/wiki/Tenocyclidine
accessed on 28/12/2007
http//en.wikipedia.org/wiki/Phencyclidine
accessed on 28/12/2007
70
Other dangerous chemicals angel dust (PCP TCP)
http//www.isomerdesign.com/Cdsa/scheduleUN.php?sc
hedule3sectionALLstructureC accessed on
28/12/2007
  • Precursor chemical Piperidine

71
Other dangerous drugs cocaine???
  • A stimulant drug

http//en.wikipedia.org/wiki/Cocaine accesed on
27/12/2007
72
Other dangerous drugs cocaine
http//www.isomerdesign.com/Cdsa/scheduleUN.php?sc
hedule3sectionALLstructureC accessed on
28/12/2007
  • Precursor chemicals
  • Potassium permanganate
  • Methyl ethyl ketone
  • Toluene
  • Sulphuric acid
  • Hydrochloric acid

73
Other dangerous drugs GHB (Gamma
hydroxybutyrate, ??? )
  • Originally used as a sleep-aid

74
Other dangerous drugs benzodiazepine (BZD,???)
  • Sedative, hypnotic drug
  • (???????)
  • As tranquillizers (???)
  • Surreptitiously slipped into
  • the drink of the intended victim

http//en.wikipedia.org/wiki/Benzodiazepine
accessed on 28/12/2007
75
Benzodiazepines
http//en.wikipedia.org/ accessed on 28/12/2007
76
Poster from Customers excise Department
77
Poster from Customers excise Department
(http//www.isomerdesign.com/Cdsa/scheduleUN.php?s
chedule3sectionALLstructureC accessed on
28/12/2007)
78
Viagra (Sildenafil citrate)
79
For treatment of obesity Sibutramine (????)
  • trade name Meridia in the USA, Reductil in Europe
    and other countries)
  • Structurally related to amphetamines

Amphetamine
Sibutramine http//en.wikipedia.org/wiki/Sibutrami
ne accessed on 28/12/2007
80
For treatment of obesity Dexfenfluramine (??????)
http//en.wikipedia.org/wiki/Dexfenfluramine
accessed on 28/12/2007
81
overview
  • Drugs and medicine an introduction
  • Key stages of drug development
  • Some common drugs
  • Dangerous drugs
  • Chiral drugs

82
Syllabus for consideration
  • 11.4 Under relevant activities (3rd column)
  • Search and present information ion chiral drugs

83
Chiral drugs
  • What is chirality?
  • 3 types of stereoisomers
  • Importance of chirality in drug development
  • Chiral drugs in daily life

84
Chiral drugs
  • What is chirality?
  • 3 types of stereoisomers
  • Importance of chirality in drug development
  • Chiral drugs in daily life

85
What is chirality?
  • Chirality is the property possessed by a
    molecule with such spatial arrangement of atoms
    that it cannot superimpose on its mirror image.
  • The object and mirror image pair of molecules has
    the same constituents and structural formula.
  • Their relationship with each other is similar to
  • our left and right hands.

86
What is chirality?
  • The carbon atom of a simple chiral centre has
    four different groups arranged tetrahedrally.
  • Isomers of such nature are called enantiomers.

87
Chiral drugs (????)
  • What is chirality?
  • 3 types of stereoisomers
  • Importance of chirality in drug development
  • Chiral drugs in daily life

88
3 types of stereoisomers (?????)
  • Enantiomers
  • Diastereomers
  • Geometrical isomers.

89
Enantiomers (?????)
  • Enantiomers are two stereoisomers containing
    asymmetric carbon atoms related as
    non-superimposable object and mirror images.
  • If an enantiomer rotates polarized light to the
    right or in a clockwise direction, it is said to
    be the () or the dextrorotatory isomer.
  • If the plane polarized light is rotated to the
    left or in a counter-clockwise direction, the
    isomer is called as the (-) or the levorotatory
    isomer.
  • Enantiomers are identical in chemical and
    physical properties except for the direction of
    rotation of plane polarized light.

90
Diastereomers (??????)
  • Diastereomers are stereoisomers that are not
    related as object and mirror images.
  • They contain at least two asymmetric carbon
    atoms.
  • Unlike enantiomers, the physical and chemical
    properties of diastereomers can differ and it is
    not unusual for them to have different melting
    and boiling points, refractive indices,
    solubility, etc.

???
????
91
Geometrical isomers (?????)
  • Geometrical isomers are molecules with a
    carbon-carbon double bond and they are not
    optically active.
  • When the groups attached to each end of the
    double bond are on the same side, the
    stereoisomer is named as cis-isomer when the
    groups are on the opposite sides, the
    trans-isomer designation is used.

92
Chiral drugs
  • What is chirality?
  • 3 types of stereoisomers
  • Importance of chirality in drug development
  • Chiral drugs in daily life

93
Why is chirality important in drugdevelopment?
  • Biological systems like that of human beings have
    been known to exhibit chirality.
  • This is reflected by the existence of chirality
    of drug receptor areas and the requirement of
    chiral specificity on drugs.
  • In order to understand the biological effect of
    drugs, we have to distinguish the three main
    phases of their action.

94
Why is chirality important in drugdevelopment?
  • The first phase is the initial receptor
    differentiation phase, where different drugs have
    different affinity and tissue specificity due to
    receptor (??) differentiation and distribution
    for the parent compound formed.
  • The second phase is the absorption, distribution,
    metabolism and excretion phase, where the type of
    bioavailability (?????) is determined.
  • The third phase is the interaction of the drug
    with the molecular site of action, leading to the
    observed therapeutic effect (??).

95
Why is chirality important in drugdevelopment?
  • The three phases of action are based on the
    receptor theory, similar to the lock-and-key
    hypothesis proposed by the famous scientist Emil
    Fischer.
  • Receptor molecules in the body are proteins that
    exhibit high affinities for the binding of
    molecules with certain structures.
  • This is completely analogous to enzyme-substrate
    binding.
  • Mismatching of drug molecules with the targeted
    receptors may cause undesirable side effects such
    as requirement of higher dosage and increased
    toxicity.

96
Why is chirality important in drugdevelopment?
  • All pharmacological activity may reside in one
    enantiomer.
  • The therapeutic inactive isomer is regarded as an
    impurity that possesses a different or
    undesirable pharmacological entity.
  • This situation may become even more acute if the
    active enantiomer exhibits a low therapeutic
    value or there is clinically significant
    toxicity.
  • A well-known example of therapeutic-specific pair
    is the R- and S-enantiomers of thalidomide (the R
    and S designation, after Cahn, Ingold and Prelog,
    is a way of naming enantiomers by their
    structures).

97
Why is chirality important in drugdevelopment?
98
Why is chirality important in drugdevelopment?
  • The R-enantiomer is an effective sedative (???),
    which is a medication with calming and soothing
    effect that relieves anxiety(????) and promotes
    sleep(??).
  • However, the S-enantiomer may cause teratogen
    (??) formation.
  • A teratogenic foetus is one with deficient,
    redundant, misplaced or grossly misshapen
    parts.(???????????????????)
  • S-Thalidomide was shown to be responsible for
    over 2,000 cases of serious birth defects in
    children born of women who took it during
    pregnancy.

99
Chiral drugs
  • What is chirality?
  • 3 types of stereoisomers
  • Importance of chirality in drug development
  • Chiral drugs in daily life

100
What drugs in our daily life are chiral?
  • Chirality is an essential dimension in
    pharmacology.
  • Worldwide sales of chiral drugs in
    single-enantiomer forms continue to grow.

101
What drugs in our daily life are chiral?
  • The commonly used single-enantiomer drugs are
    grouped as follows
  • Cardiovascular disease (???)
  • Atorvastatin calcium (?????)
  • Simvastatin (????)
  • Pravastatin sodium (?????)and
  • Valsartan (???)
  • Central nervous system(????????)
  • Paroxetine hydrochloride (??????)and
  • Sertraline hydrochloride (?????)

102
What drugs in our daily life are chiral?
  • The commonly used single-enantiomer drugs are
    grouped as follows
  • Respiratory (??????)
  • Fluticasone propionate (???????) and
  • Salmeterol (????)
  • Hematology (????)
  • Clopidogrel bisulfate (???????)
  • Gastrointestinal (????)
  • Esomeprazole magnesium (???????)
  • Antibiotic (???)
  • Amoxicillin and (??????)
  • Potassium clavulanate (?????)

103
overview
  • Drugs and medicine an introduction
  • Key stages of drug development
  • Some common drugs
  • Dangerous drugs
  • Chiral drugs
About PowerShow.com