Introduction to practical pharmacology(part1) Sources and dosage forms of drugs

1. General Introduction
to Pharmacology
By Dr. Sameh Abdel-Ghany

2. Pharmacology Definition
It is science dealing with drugs.
Drug:
 a chemical agent that stimulates
or inhibits an existing cell
function but not create new one

3. Drug Sources
Biosynthetic
Synthetic
Natural sources
Semisynthetic

4. Natural Sources
Text
Plants
Animals
Microbiological
Natural SourcesMinerals

5. A- Plant Sources
Examples:
Rauwolfia
serpentina
TobaccoPapavarum
somniferum
Atropa
belladonna
ReserpineNicotineMorphineAtropine

6. Examples
Digitalis lanataDigitalis Fox glove

7. Examples
ginger oil
‫الزنجبيل‬ ‫زيت‬
eucalyptus oilpeppermint oil
‫النعناع‬ ‫زيت‬
clove oil
‫القرنفل‬ ‫زيت‬

8. Examples
cod liver oil
‫الحوت‬ ‫كبد‬ ‫زيت‬
peanut oil
‫الفول‬ ‫زيت‬‫السودانى‬
croton oilcastor oil
‫الخروع‬ ‫زيت‬
olive oil
‫زيت‬‫الزيتون‬

9. Examples
gum tragacanthGum acaciapsyllium seedsgut agar

10. B-ANIMAL SOURCES :
Examples
VaccinesInsulin

11. C-MICROBIOLOGICAL SOURCES
 Many life-saving drugs are
obtained from fungi, moulds and
bacteria
 e.g. penicillin from
Penicillium notatum

12. II. SEMISYNTHETIC SOURCES
 used to prepare drugs when the synthesis
of drugs (complex molecules) may be
difficult, expensive and uneconomical or
when the natural sources may yield
impure compounds.
 Some examples are semisynthetic human
insulin.

13. III. Synthetic
 At present majority of drugs used
in clinical practice are prepared
synthetically
 e.g as aspirin, oral antidiabetics,
antihistamines, amphetamine,
chloroquine, chlorpromazine and
thiazide diuretics.

14. IV. BIOSYNTHETIC SOURCES
 New field which is being developed
by mixing discoveries from molecular
biology, recombinant DNA
technology, DNA alteration, gene
splicing, immunology and
immunopharmacology.

15. Examples
Human insulinHepatitis-B vaccine

17. Uses of drugs
I. Treatment of diseases
II. Prevention of diseases
(Prophylactic)
III.Diagnostic
IV.Prevention of normal biological
function

18.  Processes involved in drug therapy:
1. Pharmaceutical
 Active ingredient obtained from any
source should be put in proper dosage
forms to be absorbed

19.  Processes involved in drug therapy:
2. Pharmacokinetics
 It is the action of body toward drug given
 It consist of 4 precesses:absorptiob –
distribution – metabolism and excretion
(ADME)

20.  Processes involved in drug therapy:
3. Pharmacodynamics
 It is the effect of drug on body
 It includes mechanism of action

21.  Processes involved in drug therapy:
4. Pharmacotherpeutic
 It deals with use of drug diagnosis ,
prevention and treatment

22. Dosage Forms

23. Divisions of Dosage forms
Liquid
Solid
Semisolid
Divisions
of dosage
forms

24. I. Liquid Forms
Aqueous preparations Alcoholic preparations
1.Solutions
2.Syrups
3.Emulsions
4.Suspension
5.Infusions
6.Decoction
7.Lotion
1.Elixirs
2.Spirits (Essences)
3.Tinctures

25. 1. Aqueous preparations
I. Solutions :
 are homogeneous mixtures of
one or more solutes dispersed in
a dissolving medium (solvent).

26. II.Syrups:
 are aqueous solutions containing:
a sugar or sugar substitute ±
flavoring agents

27. III. Suspensions
 are mixtures of small water insoluble solid
drug particles dispersed in water using
suspending agent e.g. gums.

28. IV. Emulsions
 are milky solutions with bitter taste and
odour.
 It is intimate mixture of two immiscible
liquids.

29. V. Decoction : obtained
by boiling in water
dried plants.
VI.Infusion: obtained by
soaking dried plants in
cold or boiling water.
like decoctions, they
spoil quickly

30. 2. Alcoholic preparations:
I. Elixirs:
 sweetened and flavoured
hydroalcoholic solutions that contain
varying amounts of alcohol.
 may be non-medicated to be used
only as vehicles (e.g. bitter orange
elixir) or medicated when they
include specific drug (e.g. barbital
elixir).

31. Example

32. II. Spirits (Essences):
 volatile oils dissolved in alcohol
 e.g. peppermint spirit, and lemon spirit.

33. III.Tinctures:
alcoholic solutions of non-volatile
substances (vegetables).
e.g. tincture belladonna

34. II. Solid Forms
Tablets
Capsules
Powder
Solid
forms

35. A. Tablets
1)Tablets that are swallowed
whole

36. 2)Effervescent tablets

37. 3)Chewable tablets

38. 4)Buccal and sublingual tablets

39. 5)Controlled-release tablets

40. 6)Lozenges

41. B. Capsules
1)Hard gelatin capsules

42. 2)Soft gelatin capsules

43. 3)Controlled-release capsules

44. C. Powders
 may be dispensed in small paper packets
or in bulk.

45. Cont.
 It may be formulated in the form of
effervescent granules

46. III. Simisolid Forms
Suppositories
Ointments
Creams
Liniments
Gel

47. a- Ointment

48. b- Cream

49. c- Liniment

50. d- Gel

51. e- Suppositories

52. IV. Inserts, Implants, and Devices
 used to control drug delivery for localized
or systemic drug effects.
Device e.g artificial
pancreas
Implant e.g Norplant

53. V. Transdermal Patches
 deliver drugs directly through the skin and
into the bloodstream.
 Example Nitroglycerin patches and
nicotine patches

54. VI. Targeted Drug Delivery Systems
A) Macromolecular
carrier systems
TDDS
B) Particulate drug
Delivery systems
1- Liposomes:
2- Microencapsulation .

56. A) Macromolecular carrier systems
 drug can be attached to the polymer chain
either directly or via a spacer.
 Attachment of polyethylene glycol (PEG)
to proteins can protect them from rapid
hydrolysis or degradation within the body,
and increase blood circulation time and
lower the immunogenicity of proteins
 e.g. PEGylated forms of interferons

57. B) Particulate drug Delivery systems
I. Liposomes:
 Water-soluble drugs can be entrapped in
liposomes by intercalation in the aqueous
bilayers, while lipid-soluble drugs can be
entrapped within the hydrocarbon interiors
of the lipid bilayers.
 e.g amphotericin B formulated in
liposomes .

59. II. Microencapsulation
 is a technique that involves the
encapsulation of small particles or solution
of drugs in a polymer film or coat.
 e.g. Lupron Deopt