Rajeshwari .....pharm D .......Routes of administrations...classified into two....local and Systemic.....pharmacology....

1. ROUTES OF
ADMINISTRATION

2.  Drugs may be administered by various routes.
The choice of the route in a given patient
depends on the properties of drugs and patient
requirements.
 The routes of administration can be divided
into :
 LOCAL
 SYSTEMIC

3.  LOCAL
 Topical
 Arterial
 Deeper tissues
 Intrathecal
 Retro tubular
 Intrathecal

4.  SYSTEMIC
 Oral
 Sublingual
 Rectal
 Cutaneous
 Inhalations
 Nasal

5.  Parenteral
 Intravenous
 Intramuscular
 Intraperitoneal
 Transdermal
 Subcutaneous
1.LOCAL: These routes can only be used for localized
lesions at accessible sites and for drugs whose systemic
absorption from these site is minimum or absent.
Ex: lotion,ointment,cream,powder,paints,drops etc.

6.  Drugs can be efficiently delivered to localized
lesions on skin, nasal mucosa, eyes, vagina etc.
 ARTERIAL SUPPLY: Here drug is injected
directly into arteries. It is used in the treatment
of :
 Peripheral vascular diseases
 Local malignancies
 Diagnostic studies like angiograms

7.  DEEPER TISSUES: Certain deep areas can be
approached by using a syringe and needle, but
the drug should be in a form that systemic
absorption is slow.
 INTRATHECAL: Injected into subarachnoidal space
for actions on CNS.
 EX: SPINAL ANAESTHETICS
 LIMITATIONS: strict aseptic precautions are
must.

8.  INTRAOCULAR: injected into a joint for treatment
of arthritis and other joint diseases.
 Ex: hydrocortisone injection in rheumatoid arthritis.
 RETROTUBULAR:EX: Hydrocortisone acetate
behind the eye ball.
• SYSTEMIC ROUTE: Drugs administered through
systemic route is intended to be absorbed into
Blood stream and distributed allover including site of
action, through circulation.

9.  1.ORAL:
 Advantages: safest route
 Most convenient
 Most economical
 Drugs can be self administered
 Non-invasive route
 Disadvantages:Onset of action is slower as
absorption needs times.
 Irritable and unpalatable drugs can be administered

10.  There may be irregularities in absorption
 Some drugs may be destroyed by gastric juices ex:
Insulin
 Some drugs may not be absorbed due to certain
physical and chemical characteristics.. Ex:
streptomycin is not absorbed orally.
 Oral preparations cannot be given to unconscious
patients.

11.  2. SUB LINGUAL:
 Advantages: first pass metabolism is avoided
because drug directly reaches systemic circulations.
 Absorption is rapid within minutes to reach
circulation.
 After desired effect is obtained, drug can be spat out
to avoid the unwanted effects.

12.  DISADVANTAGES: Buccal ulceration may occur
3.RECTAL:
ADVANTAGES: Gastric irritation is avoided
 Can be administered by unskilled persons
 Useful in unconscious patients
 Used in geriatric patients with vomiting, those who
unable to swallow , and after gastro intestinal
surgery.

13.  DISADVANTAGES:
 Irritation of rectum may occur
 Absorption may be irregular and unpredictable.
 Ex: enema, predinsolone enema in ulcerative colitis,
evacuation enema in surgeries, radiological
examination of gut.
4.CUTANEOUS: Highly lipid soluble drugs can be
applied over the skin for slow and prolonged
absorption.

14.  Drug can be incorporated in an ointment and
applied over specified over area of skin.
Absorption of drug can be enhanced by
rubbing the preparation , by using oily base
and by an occlusive dressing.
5. INHALATIONS:
advantages: Almost instantaneous absorption
of drug is achieved because of large surface of
lungs, high vascularity, thin alveolar
membrane.

15.  In pulmonary diseases , it serves almost as a
local route as the drug is delivered at desired
site making it more effective and less harmful.
 DISADVANTAGES: Irritant gases may
enhance pulmonary secretion , should be
avoided.
Drug particles may induce cough
6. NASAL: Administered either for systemic or
local effects.

16.  Ex: systemic absorption – oxytocin spray
 Local absorption: budesonide nasal drops
6.PARENTERAL: Routes of administration other
than enteral route are known as parenteral
routes.
 ADVATNAGES: Action is more rapid
 Employed in unconscious people also
 First pass met5abolism is avoided.

17.  DISADVANTAGES: Asepsis must be maintained.
 Injections are painful
 More expensive, less safe, injury to nerves may
occur.
PARENTERAL ROUTES INCLUDES:
A. INTRA VENOUS:
 ADVANTAGES: Most useful in emergencies
 Provides 100% bioavailability
 Large volumes of solutions can be given

18. DISADVANTAGES: Once injected, drug cannot
be withdrawn.
 Only aqueous solutions can be given by intra
venous but not oily suspensions
 Self medication is difficult
 Irritation of veins may cause thrombophelbitis.

19. B. IM: absorption is rapid.
 soluble substances, mild irritants,
suspensions and colloids are injected by the
route.
 DISADVANTAGES:
 May be painful
 Local infection and tissue necrosis may occur.
 Some drugs like heparin, are avoided by IM.

20.  C. IP: Peritoneum offer large surface area for
absorption.
 Also used for peritoneal dialysis
D. TRANSDERMAL: Drugs is injected into layers of
skin raising a bleb.
 by multiple punctures of epidermis through a drop
of drug.
 Ex: small pox vaccine.

21.  E. SUBCUTANEOUS: drugs are deposited in sc
tissue, ex: insulin, heparin.
 Absorption is slow, largely uniform making
drug long acting.
 Patients can be trained for self administered.

22. THANK YOU