Routes of drug administration PPT

1. Routes of drug
administration
Dr. Ravi Mundugaru
Assistant Professor
dept. of Pharmacology
AIMS, B.G.Nagara, Karnataka

2. Factors
 Physical & Chemical properties of
drug
 Site of desired action
 Rate & Extent of absorption
 Effect of digestive juices & first pass
metabolism
 Routine treatment / Emergency
 Accuracy of dosage required
 Condition of patient

3. Routes of drug administration
Local Systemic
Enteral
--Oral
--Sublingual
--Rectal
Parenteral
--Inhalational
--Injections
--Transderma

5. Local Route
 Oral cavity: Nystatin, Clotrimazole
 GIT: Neomycin
 Rectum & Anal canal: Enema (
Methylprednisolone)
Suppository ( Bisacodyl )
 Eye, Ear, Nose
 Bronchi: Salbutamol
 Vagina
 Urethra: Lignocaine
 Infiltration anaesthesia

6. Systemic route
 Oral route
TABLE
T
ENTERIC-COATED
TABLET
CAPSULE
MIXTURE & SYRUP

7. Oral route
 Advantages:
◦ Safer
◦ More convenient
◦ Economical
◦ Painless
◦ Self administration
possible
◦ Complications of
parenteral therapy
avoided
 Disadvantages:
◦ Slow onset
◦ Irritant &
unpalatable drugs can
not be given
◦ Vomiting, unconscious
pts.- not useful
◦ Drugs which are
destroyed by
digestive juices --
not
useful

8. Enteric – Coated tablet
 Coating made of cellulose, acetate,
etc.
 Prevent gastric irritation.
 Protect drug from gastric acid.
 Retard absorption- prolonging duration
of action of drugs

9. Sustained or time release
preparation
 Different coating dissolving at different
intervals of time.
 Advantage:
1. Prolong duration of action
2. Reduces the frequency of
administration
3. Improves patient compliance
 Example: Nifedipine

10. Sublingual route
Placed under the tongue e.g.
nitroglycerine.
•Advantages:
1. Rapid onset of action
2. First pass metabolism is avoided
3. Avoids degradation of drug in
stomach
4. Termination of drug action is

11. Rectal route
 Suppositories:
Indomethacin for Rheumatoid
Arthritis
 Enema:
Diazepam for Status
epilepticus in children

12. Parenteral Route
Advantage.
 Unconscious & un-
cooperative pt.
 Vomiting &
diarrhoea
 Emergencies.
 Irritant drugs
(I.V.route)
 Drugs which are
destroyed by G.I.
enzymes - given
safely.
Disadvantage.
 More expensive
 Inconvenient
 Self medication is
difficult
 Painful
 Chances of local
tissue injury,& injury
to nerves
 Requires sterilization
of instruments & skill

13. Inhalation
Advantage
 Instant absorption
 Local route in
pulmonary
diseases
 Avoids first pass
metabolism in liver
 Blood levels of
volatile anesthetics
can be
conveniently
Disadvantage
 Irritant gases can
increase
pulmonary
secretions

14. Injections.
 Intradermal route
1. Drug is injected into layers of skin
2. Raising a bleb e.g. BCG vaccine,
allergy tests
3. By multiple punctures of epidermis
e.g. small pox vaccine
4. Only small quantities
5. May be painful

15. Subcutaneous.
Drug injected into subcutaneous tissue
example: Insulin
Advantage
 Self administration
possible. (Insulin)
 Depot preparation
can be inserted
(Norplant)
Disadvantage
 Suitable for non-
irritant drugs.
 Drug absorption is
slow.

16. Intramuscular.
 Deltoid
 Gluteus maximus
 Lateral aspect of thigh

17. Intramuscular.
Advantage
 Absorption rapid
 Mild irritant, depot
preparation can be
given.
Disadvantage
 Aseptic condition
needed.
 Painful.
 Self administration
not possible
 May injure nerves

18. Intravenous
 Drugs injected directly into blood
stream through a vein.
 Administered as
1. Bolus ( heparin )
2. Slow i.v. injection ( morphine )
3. i.v. infusion (dopamine infusion in
cardiogenic shock)

19. Intravenous
 Advantage
1. Bioavailability 100%
2. Emergency
3. Large volume can be
administered.
4. Highly irritant drug
administered
5. Constant plasma
level maintained.
 Disadvantage
1. Once injected, cannot
be withdrawn
2. Thrombophlebitis
3. Extravasation →
severe
irritation/sloughing
4. Only aqueous
solutions can be given
5. Self administration
difficult
6. Aseptic measures
required

20. Intra-arterial route
 Rarely employed
 Diagnostic studies- coronary
angiography

21. Intrathecal route
 Drug injected into sub- arachnoid
space
 Spinal anaesthetics ( lignocaine ),
antibiotics (amphotericin-B)

22. Intra-articular route
 Drugs injected directly into joint space
 Hydrocortisone injection for
Rheumatoid arthritis.
 Disadvantage:
 Strict aseptic precaution
needed.
 Repeated administration
damage articular cartilage.

23. Transdermal route
Scopolamine for
Motion sickness

24. Transdermal route
Advantage
 Provide smooth
plasma
concentration
 Minimize side
effects
 Patient compliance
 Duration of action
prolonged
Disadvantage
 Local irritation
 Patch may fall
unnoticed
 expensive

25. Special drug delivery system
 Transdermal patch
 Ocuserts
 Progestaserts
 Liposomes as drug carriers
 Prodrugs
 Computerised miniature pumps
 Monoclonal antibodies as drug
carriers

26. Thank you