This presentation includes various routes of drug administration. It also includes advantages and disadvantages of various routes.

1. ROUTES OF DRUG
ADMINISTRATION
Dr. Rupali A. Patil
Associate Professor & Head - Pharmacology
GES’s Sir Dr. M. S. Gosavi College of Pharm. Edu. & Res., Nashik

2. 2

3. FACTORS GOVERNING CHOICE OF ROUTE
• Physical & chemical properties of drug-
solid/liquid/gas; solubility, stability, PH, irritancy
• Site of desired action- localized and approachableor
generalized and non approachable
• Rate & extent of absorption from various routes
• Effect of digestive juices & first pass effect
• Rapidity of the desired response- emergency/routine
• Accuracy of dosage
• Condition of the patient- unconscious, vomiting
3

4. ENTERAL routes
A. ORAL
B. SUBLINGUAL
C. RECTAL
4

5.  1. ENTERAL
A. Oral
- Most common route of administration
- Most variable
- Most complicated pathway
- Cheapest
- Non - invasive
[NOTE: most drugs are absorbed in theGIT &
encounter the liver before they are distributed into
the general circulation]
po (from the Latin per os) oral route of medication administration
5

6. Advantages
1. Safe
2. Convenient-self- administered
3. Pain free, non-invasive and easy to take
4. Economical- compared to other parenteral routes
5. Usually good absorption- takes place along the whole
length of the GI tract
6. No need for sterilization
6

7. Disadvantages
1. Slow absorption: slow action - can not used in emergency
2. Irritable and unpalatable drugs- nausea and vomiting
3. Cannot be used Unco-operative, vomiting and unconscious
patients
4. Some drugs destroyed
5. Sometimes inefficient drug absorbed,some drugs are
not absorbed likestreptomycin
6. First-pass effect- Due to Biotransformation
7. Food–Drug interactions and Drug-Drug interactions
7

8. Dosage forms
Capsules, powders
Tablets, spansules
Syrup, emulsion
Suspension, elixirs
Tablets Hard- gelatin capsule
Spansule
Soft- gelatin capsule
Syrup
8

9.  1. ENTERAL
B.Sublingual
- Placement under the tongue
- Allows the drug to diffuse into the capillaries &
therefore to enter the systemiccirculation
9

10. Advantages:
•Drug absorption is quick
•Quick termination
•Drug bypasses the intestine & liver : 1st -pass avoided
•Can be self administered
•Economical
Disadvantages:
•Unpalatable & bitter drugs
•Irritation of oral mucosa
•Large quantities not given
•Few drugs are absorbed
10

11. 1. ENTERAL
c. Rectal
- Useful if the drug induces vomiting if given orally or if
the patient is already vomiting
- Drainage of the rectal region bypasses the portal
circulation (No First Pass effect)
- Similar to the sublingual route, it prevents the
destruction of the drug by intestinal enzymes or by
the low pH in the stomach
- Unco-operative patient / in childrens
[commonly used to administer anti – emetic agents] 11

12. Disadvantages:
 Inconvenient
 Absorption is slow and erratic
 Irritation or inflammation of rectal mucosa can occur
By Suppository or enema:
E.g. aspirin,
theophylline,
chlorpromazine
12

13. PARENTERAL routes
SC / subcutaneous
IM /
intramuscular
IV / intravascular
13

14. Parenteral
Used for drugs which are
 Poorly absorbed in the GIT
 Unstable
 For unconscious patients
 Circumstances with
rapid onset of action
 Provides the most
control over the actual
dose delivered to the
body
 Greek words
 Para: outside
 Enteron: the intestine
14

15. parenteral
 Advantages
 Fast: 15–30 seconds forIV,
3–5 minutes for IM and
subcutaneous(SC)
 100% bioavailability
 suitable for drugs not
absorbed by the gut or
those that are too irritant
(anti-cancer)
 IV can deliver continuous
medication, e.g., morphine
for patients in continuous
pain, or saline drip for
people needing fluids
 Disadvantages
 more risk of addiction
when it comes toinjecting
drugs of abuse
 Belonephobia, the fear of
needles and injection.
 If needles are shared,there
is risk of HIV and other
infectious diseases
 It is the most dangerous
route of administration
 If not done properly,
potentially fatal air boluses
(bubbles) can occur.
 Need for strict asepsis
15

16. 16

17. 2. PARENTERAL
a. IV / intravascular
- Most common parenteral route
- For drugs which are not absorbed orally
- Bypasses the liver
- Permits a rapid effect & a maximal degree of control
over the circulating levels of the drug
- Can introduce bacterial contamination at the site
- Can cause hemolysis
17

18. IV route…
Advantages
 Bioavailability100%
 Desired blood
concentrations achieved
 Large quantities
 Vomiting & diarrhea
 Emergencysituations
 First passavoided
 Gastric manupalation
avoided
Disadvantages
 Irritation& cellulitis
 Thrombophelebitis
 Repeated injections not
Always feasible
 Less safe
 Technicalassistance
required
 Danger of infection
 Expensive
 Less convenientand painful
18

19. 2. Parenteral
b. IM / intramuscular
Drugs administered
aqueous sol’n
specialized depot
preparations
19

20. IM route…
Advantages
 Absorption
Reasonablyuniform
 Rapidonsetof action
 Mild irritantscan be given
 First passavoided
 Gastricfactorscan be avoided
Disadvantages
 Only upto10ml drug given
 Local pain and abcess
 Expensive
 Infection
 Nerve damage
20

21. 2. Parenteral
c. SC / subcutaneous
- like IM requires absorption &
somewhat slower than the IV
route
IMPLANT :a tablet or porous
capsule is inserted into the
loose tissues by incision of the
skin, which is then stiched up.
example : certain hormonal
drugs 21

22. INTRA-ARTERIAL
 Rarely used
 Anticancer drugs are given for localized effects
 Drugs used for diagnosis of peripheral vascular
diseases
22

23. INTRA-ARTICULAR
 injections of
antibiotics and
corticosteroids are
administered in
inflammed joined
cavities by experts.
example:
hydrocortisone in
rheumatoid arthritis
23

24. INTRADERMAL
 drug is given within skinlayers
(dermis)
 Painful
 Mainly used for testing
sensitivity to drugs.
e.g. penicillin,ATS(antitetanus
serum)
INOCULATION:administration of
vaccine (like small pox vaccine)
24

25. 3. Others
a. Inhalation
- Provides a rapid delivery of a
drug across a large surface
area of the mucus
membranes of the
respiratory and the
pulmonary epithelium
- Effect is as rapid as IV
injection
- For gaseous drugs
25

26. Advantages
 Fastest method, 7–10 seconds
for the drugto reach the brain
Disadvantages
 Typically a more addictive route of
administration because it is the
fastest, leading to instant
gratification.
 Difficulties in regulating the exact
amount of dosage
 Patient having difficulties
administering a drug via inhaler
26

27. 3.Others
b. Intranasal
- Through the nose
eg. : desmopressin,
salmon calcitonin,
cocaine
27

28. .Others
c. Intrathecal, intraventricular
- Introducing drugs directly into
the cerebrospinalfluid /CSF
Eg., amphotericin B
28

29. 3.Others
d.Topical
- Is used when a local effect
of a drug is required
- Eg. clotrimazole, atropine
29

30. Topical Routes of Administration
 Topical administration is the application of a drug
directly to the surface of the skin
 Includes administration of drugs to any mucous
membrane
vagina
urethra
colon
 eye
 nose
 ears
 lungs
30

31. Topical Dosage
Forms
Dose forms for topical administration include:
 Skin:
 creams
 ointments
 lotions
 gels
 transdermal patches
 disks
• Eye or ear:
– solutions
– suspensions
– ointments
• Nose and lungs:
– sprays and powders
31

32. Topical Route
Advantages and Disadvantages
 Local therapeutic effects
 Not well absorbed into the deeper layers ofthe skin or
mucous membrane
lower risk of side effects
 Transdermal route offers steady level of drug in the
system
sprays for inhalation through the nose may
be for local or systemic effects
32

33. Topical route
Produce local effect to
 Skin (percutaneous) e.g. allergy testing, topical
local anesthesia
 Mucous membrane of respiratory tract
(Inhalation) e.g. asthma
 Eye drops e.g. conjunctivitis
 Ear drops e.g. otitis externa
 Intranasal, e.g. decongestant nasal spray
33

34. 3. Others
e.Transdermal
- achieves systemic effects by application of
drugs to the skin, usually by using a
transdermal patch.
- Rate of absorption varies markedly
- stable blood levels
- no first pass metabolism
- drug must be potent or patch becomes
too large
Eg. nitroglycerin
34

35. 35

36. Route for administration
-Time until effect-
 intravenous
 intraosseous
 endotracheal
 inhalation
 sublingual
 intramuscular
 subcutaneous
 rectal
 ingestion
 transdermal (topical)
30-60 seconds
30-60 seconds
2-3 minutes
2-3 minutes
3-5 minutes
10-20 minutes
15-30 minutes
5-30 minutes
30-90 minutes
variable (min to hrs)
36

37. Dosage forms available for different routes
37