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Master of Pharmacy Degree at King’s College London

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Title: Master of Pharmacy Degree at King’s College London


1
Master of Pharmacy Degreeat Kings College
London
2
The College
  • Kings is one of the two founding Colleges of the
    University of London a major international
    university in the heart of London with
    approximately 14,000 undergraduate students and
    more than 5,000 postgraduates in nine Schools and
    five campuses.
  • School of Biomedical and Health Sciences
  • Dental Institute
  • School of Humanities
  • School of Law
  • School of Medicine
  • Florence Nightingale School of Nursing
    Midwifery
  • School of Physical Sciences Engineering
  • Institute of Psychiatry
  • School of Social Science Public Policy

3
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4
The Department of Pharmacy
  • Master of Pharmacy
  • Master of Science Programmes
  • Biopharmacy
  • Pharmaceutical Technology
  • Pharmaceutical Analysis Quality Control
  • Master of Science / Diploma Programmes
  • Primary Care Community Pharmacy
  • Supplementary Prescribing
  • Research Degrees in the Pharmaceutical Sciences
  • Pharmacy Practice

5
Pharmaceutical Education Training in the UK
  • Master of Pharmacy (MPharm) Degree
  • Four Years
  • Pre-Registration Training One Year
  • Hospital Pharmacy
  • Community Pharmacy
  • Hospital or Community / Industry or Academic
    Pharmacy
  • Professional Examination
  • Registration Member of the Royal Pharmaceutical
    Society of GB (RPSGB)

6
MPharm 1 Principles of Pharmacy
  • Pharmacy orientation course
  • (First three weeks)
  • Interprofessional Education
  • (Throughout the Year)
  • Biochemical Basis of Therapeutics
  • Pharmacy Practice Biopharmacy
  • Physical Pharmaceutics
  • Chemistry of Drugs

7
  • MPharm 2 Pharmacy Therapeutics
  • Formulation Analysis of Drugs
  • Nervous System
  • Respiratory Musculoskeletal Systems
  • Cardiovascular Renal Systems
  •   
  • MPharm 3 Pharmacy Therapeutics
  • Medicines Discovery Design
  • Gastrointestinal System Skin
  • Infection Pharmaceutical Microbiology
  • Endocrine System Cancer
  • Pharmacy Law Ethics

8
MPharm 4 Pharmacy into Practice
  • Semester 1 Research Project
  • Semester 2 Preparation for Practice
  • Electives - Two from
  • Chemical Mediators Disease
  • Plants Pharmacy
  • Drug Development from Natural Sources
  • Drug Delivery
  • Science of Dosage Form Design
  • Drug discovery Design
  • Drug Metabolism
  • Drug Toxicity

9
Department of Pharmacy and Overseas Study
European Union Erasmus-Socrates
  • Undergraduate students
  • PhD students
  • Post-doctoral staff
  • Academic staff
  • Austria
  • University of Vienna
  • France
  • Joseph Fourier University, Grenoble
  • Germany
  • Johann Wolfgang Goethe University,
  • Frankfurt
  • Philipps University, Marburg
  • Hungary
  • Semmelweis University, Budapest
  • Italy
  • University of Bologna
  • University of Calabria
  • University of Padova
  • University of Parma
  • Poland
  • Medical University of Lódz
  • Spain

10
Stereochemistry Biological Activity
  • Andrew J. Hutt
  • Department of Pharmacy,
  • Kings College London.

11
Pharmaceutical Medicinal Chemistry
  • No drug was ever used because it had an
  • Interesting synthetic pathway
  • An unusual stability profile
  • Required a particularly sophisticated
  • analytical technique.
  • Drugs are used because they do something!

12
  • .. and they do something as a result of
    their molecular structure, which determines
  • Physicochemical properties
  • Chemical / biochemical reactivity
  • Shape
  • STEREOCHEMISTRY.

13
  • Stereochemistry
  • Concerned with the three dimensional spatial
    arrangement of the atoms within a molecule.
  • Stereoisomers
  • Compounds with the same molecular
    connectivity but differ in the spatial
    arrangement of their constituent atoms or groups.

14
  • Enantiomers
  • Stereoisomers which are non-superimposable
    mirror images of one another.
  • Diastereoisomers
  • Stereoisomers which are not enantiomeric.

15
Stereogenic centre
16
Chiros Greek Handed
17
Sequence Rule Designation
18
Stereoisomers of Ibuprofen
19
Stereogenic S P centres
20
Stereoisomers of Phenylpropanolamine
21
Phenylpropanolamine UK Confusion
  • Independent risk factor for hemorrhagic stroke in
    women1
  • Withdrawn in the USA (FDA, Oct. 10, 2000)
  • ()-norpseudoephedrine in European
    preparations(?)-norephedrine in North
    America(Martindale 32nd Pharm J, Nov. 11, 2000)
  • (?)-norephedrine in USA and Europe structure of
    norpseudoephedrine presented in the British
    Pharmacopoeia 2000 (Pharm J, Dec. 2, 2000)

1Kernan WN, et al. N Engl J Med.
20003431826-1832.
22
Glyceraldehyde enantiomers
23
Stereochemical Designations
  • Spatial Arrangement
  • R/S
  • D/L
  • Physical Properties
  • d,l
  • (),(-)

24
Optical Rotation (1)
25
Optical Rotation (2)
  • Chloramphenicol
  • 1R,2R-absolute configuration
  • Dextrorotatory in ethanol
  • Laevorotatory in ethyl
    acetate
  • Moxalactam
  • Mixture of two epimeric diastereoisomers both
    of which
    are laevorotatory

26
Nomenclature
  • Dextro / Dex () Es (S)
  • Dexamethasone Esomeprazole
  • Dexamfetamine Escitalopram
  • Dextromethorpan Eszopictone
  • Dextropropoxyphene
  • Levo / Lev (-) Ar (R)
  • Levamisole Arformoterol
  • Levobunolol Arflurbiprofen
  • Levodopa
  • Levonorgestrel

27
D-Glucose
28
Amino Acids
29
  • Differences between stereoisomers are hard to
    detect normally, but become much more marked in
    a chiral environment

30
Chiral Biological Macromolecules
  • Proteins
  • Enzymes
  • Structural elements of membranes
  • Receptors
  • Carbohydrates
  • Nucleic acids
  • Chiral building blocks of L-amino acids and
    D-carbohydrates.

31
Helical structures
32
Differences Between Enantiomers Odor
  • R S
  • Limonene Oranges Lemons
  • Carvone Spearmint Caraway

33
Differences Between Enantiomers Taste
  • D L
  • Asparagine Sweet Tasteless
  • Leucine Sweet Bitter

34
Enantiomeric DiscriminationEasson Stedman
Model (1933)
35
Adrenaline Adrenergic Receptors
36
Pharmacology Pharmacodynamics
  • Stereoselectivity of drug action has been known
    for a number of years.
  • Many natural ligands are chiral, eg,
    transmitters, hormones, etc.

37
Pharmacodynamic Considerations
  • Greatest differences between a pair of
    enantiomers occur at the level of receptor
    interactions.
  • Additional Terminology
  • Eutomer enantiomer with higher
    affinity/activity.
  • Distomer enantiomer with lower
    affinity/activity.
  • Eudismic Ratio Ratio of the Eutomer/Distomer
    affinities or activities.
  • Eudismic Ratios of 100 to 1000 fold are not
    uncommon.

38
Eudismic Ratio
  • Terminology applies to a particular activity of a
    drug.
  • Dual action drug the Eutomer of one activity may
    be the Distomer for another.
  • Propranolol S-enantiomer 40-100 fold more potent
    than the R- as a ß-adrenoceptor antagonist
    similar activity with respect to their membrane
    stabilising properties.
  • Eudismic Ratios may also vary with receptor
    subtypes.
  • Noradrenaline ER (R/S) a1, 107 a2, 480.
  • a-Methylnoradrenaline ER (1R,2S/1S,2R) a1,
    60a2, 550.

39
Amosulalol Enantiomer Activity
Eudismic Ratio
Eutomer pA2 (Enantiomer)
Tissue
Receptor
  • Adrenoceptor agonist
  • Nonspecific ß
  • Selective a1

48
7.71 (-)
Rat atrium
ß1
Guinea pig trachea
ß2
47
7.38 (-)
14
8.31 ()
Rabbit aorta
a1
3
5.36 ()
Rat vas deferens
a2
40
Stereoselectivity of TerfenadineH1-Antihistamine.
  • Inhibition of mepyamine binding R-, 6.4µM S-,
    7.5 µM.
  • Ligand binding at H1-receptors Ki values
  • R-, 7.6 S-, 6.81.
  • Blockade cardiac K channels R-, 1.19 µM S-,
    1.16 µM.
  • Stereogenic centre located in a non critical
    region.

41
Sertraline Selective Serotonin Reuptake
Inhibitor
42
Formoterol
43
Pharmacodynamic Complexity activity resides in a
single enantiomer.
  • (S)-?-Methyldopa, antihypertensive.
  • (1R,2S)-?-methylnoradrenaline by dopa
    decarboxylase dopamine ß-hydroxylase.

44
Pharmacodynamic Complexity Both enantiomers have
similar activity.
  • Promethazine antihistamine enantiomers have
    similar pharmacological toxicological profiles.
  • Flecainide antiarrhythmic activity effect on
    cardiac sodium channels similar no significant
    pharmacokinetic differences.

45
Pharmacodynamic Complexity Both enantiomers
marketed with different therapeutic indications.
Propoxyphene
CH2NMe2
CH2NMe2
Me
H
H
Me
C6H5
EtCOO
C6H5
OOCEt
CH2C6H5
CH2C6H5
(-)-2S,3R Antitissive NOVRAD
()-2R,3S Analgesic DARVON
46
Pharmacodynamic Complexity Enantiomers have
opposite effects at the same receptor.
  • Picenadol
  • Opioid analgesic
  • ()-(3S,4R) enantiomer is agonist
  • (-)-(3R, 4S) enantiomer is antagonist
  • (?)-(3RS, 4RS) partial agonist

47
Pharmacodynamic Complexity One enantiomer
antagonises the side effects of the other.
  • Indacrinone
  • Loop diuretic, evaluated for treatment of
    hypertension and congestive heart failure
  • Racemate administration results in elevated uric
    acid
  • R-enantiomer diuretic, t½ 10 12
    hS-enantiomer uricosuric, t½ 2 5 h
  • Mixture SR 41 isouricemic SR 81
    hypouricemic

48
Pharmacodynamic Complexity Required activity
resides in one or both enantiomers, adverse
effects predominantly associated with one
enantiomer
  • Ketamine, general anaesthetic with analgesic
    properties.
  • S-enantiomer ca 3-fold greater affinity for the
    NMDA receptor
  • 2-4 selectivity for µ- and ?-opioid receptors.
  • Post-anaesthesia emergence reactions
  • hallucinations, vivid dreams, agitation,
  • mainly associated with the R-enantiomer.
  • Chiral Switch, the S-enantiomer being available
    in Germany.

49
Configuration Activity
50
Pharmacology Pharmacokinetics
  • Absorption active transport
  • Distribution active/selective uptake, protein
    binding
  • Metabolism numerous examples
  • Excretion active secretion or reabsorption

51
Stereoselective drug absorption
52
Stereoselectivity in plasma protein binding
  • Acidic drugs Unbound () Ratio
  • S-enantiomer
    R-enantiomer (S/R)
  • Flurbiprofen 0.048 0.082 0.59
  • Ibuprofen 0.64 0.42 1.5
  • Indacrinone 0.3 0.9 0.33
  • Pentobarbitone 26.5 36.6 0.72
  • Phenprocoumon 0.72 1.07 0.67
  • Warfarin 0.9 1.2 0.75
  • Basic drugs
  • Bupivacaine 4.5 6.6 0.68
  • Chloroquine 33.4 51.5 0.64
  • Disopyramide 22.2 34 0.64
  • Methadone 9.2 12.4 0.74
  • Mexiletine 28.3 19.8 1.4
  • Propafenone 2.5 3.9 0.64
  • Sotalol 62 65 0.95
  • Verapamil 11 6.4 1.7

53
Drug metabolismProchiral to chiral
transformation
54
Drug metabolismChiral to chiral
55
Drug metabolismChiral to diastereoisomers
56
Drug metabolismChiral Inversion of
2-Arylpropionic Acid NSAIDs
57
Enantiomeric Differences in Pharmacokinetic
Profile
58
Use of Racemates
  • Isomeric ballast
  • Clean drugs
  • Polypharmacy

59
FDA
  • The Agency is impressed by the possibility that
    the use of single enantiomers may be
    advantageous (1) by permitting better patient
    control, simplifying dose-response relationships
    (2) by reducing the extent of interpatient
    variation in drug response.

60
Potential Advantages of Single Isomer Products
  • Less complex and more selective pharmacological
    profile
  • Potential for an improved therapeutic index
  • Less complex pharmacokinetic profile
  • Reduced potential for complex drug interactions
  • Less complex relationships between plasma
    concentration and effect

61
Racemates vs Enantiomers
  • No requirement from any regulatory authorities
    for marketing single isomers
  • Choice of stereoisomeric form must be justified
    on scientific grounds

62
Racemates vs Enantiomers (Contd)
  • Configurational stability
  • Preparation not technically feasible on a
    commercial scale
  • Enantiomers have similar pharmacological and
    toxicological profiles
  • One enantiomer is shown to be inactive and not
    provide an additional body of burden
  • The use of a racemate produces a therapeutic
    effect superior to that of the individual
    enantiomers

63
Penicillamine
  • Originally introduced for the treatment of
    Wilsons disease
  • Animal toxicity weight loss, intermittent fits,
    death in rats L gtgt D
  • Mutagenicity L gt D
  • Optic neuritis with racemate in man, drug
    withdrawn (USA)

64
Dopa
decarboxylation
L-Dopa
Dopamine (natural neurotransmitter)
  • Side effects nausea, vomiting, anorexia, mental
    effects,involuntary movements, granulocytopenia

65
Thalidomide
66
Thalidomide Enantiomers
  • Both are sedative in the mouse, only
    (S)-thalidomide is teratogenic.
  • Mouse is a poor model for teratogenicity.
  • Both are teratogenic in NZW rabbits.
  • Enantiomers undergo rapid racemization in vivo
    and in vitro.
  • In man following administration of the R- and
    S-enantiomers ca 25 and 43 of the total AUC is
    due to the alternative stereoisomer.

67
Drug Chirality The 1980s
Non chiral 6
Sold as single isomer
Naturalsemisynthetic 475
461
Chiral 469
Sold as racemate
Drugs 1675
8
Sold as single isomer
Non chiral 720
58
Synthetic 1200
Chiral 480
Sold as racemate
422
68
New Chemical Entities Assessed by the UK
Medicines Control Agency (MCA/MHRA) between
1996-2000
Non-chiral 2
Naturalsemisynthetic 19
Single isomer 16
Chiral 17
NCEs 95
Racemate 1
Non-chiral 31
Synthetic 76
Single isomer 30
Chiral 45
Racemate 15
Shah Branch, 2003.
69
Racemate to Enantiomer Racemic or Chiral
Switches
  • Drug Name Class Approval Status
  • Dexfenfluramine Anoretic Withdrawn
  • Levofloxacin Antimicrobial Japan, UK, USA
  • Dilevalol ?-blocker Development stopped
  • Dexibuprofen NSAID Austria (1994), Switzerland,
    EU (2005)
  • Dexketoprofen NSAID Spain, UK
  • Levobupivacaine Local anesthetic UK
  • (S)-Ketamine Anesthetic Germany
  • Esomeprazole H-pump inhibitor UK, USA
  • (R)-Salbutamol ?2-agonist USA
  • (R)-Fluoxetine Antidepressant Development stopped
  • Cisatracurium Neuromuscular blockade UK,
    USALevocetirizine Antihistamine UK,
  • (R,R)-Methylphenidate ADHD USA
  • Escitalopram Antidepressant UK, USA
  • (S)-Amlodipine Dihydropyridine India
  • Eszopiclone Insomnia USA
  • Arformoterol ?2-agonist USA (April 2007)
  • Armodafinil Antinarcoleptic USA (Approvable
    letter, April 2007)

70
Body of Evidence
  • Im not sure I get it, Marino said, rubbing his
    eyes. How can compounds be the same but
    different?
  • Think of dextromethorphan and levomethorphan as
    identical twins, I said. Theyre not the same
    people, so to speak, but they look the same
    except one is right-handed and the other
    left-handed. One is benign, the other strong
    enough to kill. Does that help? Dr Kay
    Scarpetta
  • Patricia Cornwell, 1991

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72
Further Reading
  • A. Slovakova A.J. Hutt (1999) Chiralne
    zluceniny a ich farmakologicke ucinky. Czech
    Slovak Pharmacy, 48, 107-112.
  • A.J. Hutt J. Valentová (2003) The chiral
    switch the development of single enantiomer
    drugs from racemates. Acta Facultatis
    Pharmaceuticae Universitatis Comenenianae, 50,
    7-23.
  • R. Cižmáriková, J. Valentová A.J. Hutt (2004)
    Blokátory ß-adrenergických receptorov skupina
    chirálnych liecivenantioseparácie v skupine
    ß-blokátorov. Czech Slovak Pharmacy, 53, 9-17.
  • J. Valentová A.J. Hutt (2004) Chirálni zámena
    chiral switch cisté enantiomery léciv místo
    racemických smesí. Czech Slovak Pharmacy, 53,
    285-293.
  • R. Cižmáriková, J. Valentová, A.J. Hutt S.
    Sedáková (2005) Blokátory ß-adrenergických
    receptorov skupina chirálnych lieciv
    stereoselektivna syntéza ß-blokátorov. Czech
    Slovak Pharmacy, 54, 201-206.

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