Pharmacy syllabus

1. ROUTES OF DRUG
ADMINISTRATION OF DRUG
Mrs.Varsha Mahavir Dhulasawant
Asst.Professor
S S P Shikshan Sanstha's
Siddhi College of Pharmacy Chikhali Pune

2. Introduction
A route of administration is the path by which a drug, fluid,
poison or other substance is brought into contact with the body.
No single method of drug administration is ideal for all drugs in
all circumstances

4. Choosing Particular Route of Drug Administration
DRUG RELATED FACTORS
 Physical and Chemical properties
Compared bioavailability for different routes
PATIENT RELATED FACTORS
Condition of the patient
 Site of desired action
 Effect of digestive juice, first pass metabolism
Urgency for response
 Accuracy of dosing

5. Systemic effect
The effect produced by the drug after being effectively
absorbed in blood stream is known as Systemic effect
Local Effect
Effect produced by the drug in localized area where it is
applied (administered)is known as local effect

6. Enteral Routes
Enteron meaning intestine ,drugs directly placed in the GIT.
Three routes :
oral
sublingual and
rectal routes.
It is the safest, most economical, and convenient route of drug
administration. Tablets,Capsules,powders,mixtures, Emulsions and
gels are taken orally.

7. Oral Route
In this route of administration the drug whether liquid or solid preparation is
placed in the mouth cavity and is swallowed along with drinks such as water
milk etc. Sometimes the tablet is chewed by the patient and is then swallowed
from mouth cavity.
After administration of drug by this route absorption of drug takes place in the
intestine.

8. Safe, convenient and painless method therefore
most preferred.
Economical, sterilisation is not required
 For oral drug administration any assistance is not
required.
 Less chance of acute drug reaction
Advantages

9. Sometimes complete drug is not absorbed.
 Gastric mucosa irritation by certain drugs leads to nausea and vomiting.
Late onset of action so not effective in emergencies.
Unpleasant taste of drugs.
 Route not preferred in unconscious and uncooperative patients.
 Drug could not be administered during vomiting and diarrhoea.
Drug absorption is reduced due to complex formation of chelation.
Disadvantages

10. Certain drug preparation such as insulin undergo degradation in the GIT,
hence such preparations cannot be given by oral route in order to avoid their
degradation by digestive juices.
After oral Administration certain drugs like testosterone are destroyed in the
liver cells (hepatic first pass metabolism)

11. First-pass Effect
The first-pass effect is the term used for the hepatic
metabolism of a pharmacological agent when it is
absorbed from the gut and delivered to the liver via the
portal circulation. The greater the first-pass effect,
the less the agent will reach the systemic circulation
when the agent is administered orally

12. Normal circulation
Arteries
Portal Circulation
Arteries
Vein(capillary bed)
Vein capillary bed
Heart
One organ
Two organ
Heart
Heart
organ
Heart
vein

13. Sublingual route
Drug is kept beneath the tongue to disintegrate and get absorbed in mouth. The
drug enters the systemic circulation through diffusion in to the capillary
network.
Medicament are kept below tongue ------dissolve in mouth cavity-------absorbed
in systemic circulation
e.g……..Nitroglycerine used as in angina pectoris

14. Rapid absorption of drug due to highly vascularised site therefore fast onset
of action.
Drug do not undergo first pass metabolism. Portal circulation is by passed.
In case of any side effect drug can be withdrawn .
Drug can be administrated easily.
Less chance of infection.
 No involvement of harsh GI environment.
Advantages

15. It is sometime inconvenient to keep drug in mouth.
Small doses are required to keep in mouth.
Drug having high molecular weight cannot be absorbed.
 Unpleasant, distasteful, irritant drug cannot be administrated
through this route.
Disadvantages

16. Rectal Route
Drugs can be given in the form of solid or liquid.
a.Suppository: It can be used for local (topical) effect as well as systemic effect,
e.g. indomethacin for rheumatoid arthritis. Bisacodyl suppository
b. Enema: Retention enema can be used for local effect as well as systemic
effect. The drug is absorbed through rectal mucous membrane and produces
systemic effect, e.g. diazepam for status epilepticus in children,
1.Evacuant Enema 2. retention Enema(Local effect)

17. •Useful in the patient is having recurrent vomiting or unconscious stage.
• Potential of long term drug absorption with various intrauterine
devices (IUDs).
• Some irritant and unpleasant drugs can be introduced into rectum as
suppositories.
Advantages

18. • This is rather inconvenient and embarrassing.
• Absorption is slower, irregular and unpredictable.
• Bleeding problems such as discomfort to real
pathologies.
Disadvantages

19. The parenteral route includes the route of drug administration other than the
alimentary tract(GIT).
In latein Par means beyond and enteron means intestine.
By Parenteral route drug can be administered with injection or in some cases in
form of vapour or droplets by inhalation route
Parenteral Route

20. Parenteral Route
Parenteral route includes ( based on Site of release)
•Intradermal (Intracutaneous)
•Subcutaneous route (Hypodermic)
•Intra muscular
•Intra venous
•Intra-arterial
•Intra-thecal
• Intra-cardiac
• Intrapleural
• Intraperitoneal
• Intra-articular

22. • Parenteral route is rapid.
• It is useful for uncooperative patients
• It is useful for unconscious patients
• Inactivation by GIT enzymes is avoided
• First pass effect is avoided
• Bioavailability is 100%,ensure accurate dosage of medicaments.
.
Advantages

23. Self administration is difficult
Skill is required or special techniques of administration ,not convenient and
economical for patient.
 It is painful
 This method is expensive
 It is difficult to control or reverse the effects of drugs administered by these
routes.
It is essential follow strict aspect technique in order to avoid possibility of
infections.(sterilization)
Disadvantages

25. Intradermal route
The drug is injected in layer of the skin.
only a small quantity of the drug can be administered by this route and the injection is
painful.
This route is mostly used for diagnostic purposes and is involved in:
1.Schick test for Diphtheria
2.Dick test for Scarlet fever
3.Vaccines include DBT, polio and Bacillus Calmette–Guerin (BCG) vaccination
4.Sensitivity is to penicillin

26. Intravenous Injection
Drug is injected directly into the vein.by this route the drug rapid action and
desired blood concentration of the drug is obtained by a definite dose .

27. Immediate action takes place, onset of action found to be 15 sec.
 This route is preferred in emergency situations
 This route is preferred for unconscious patients.
 Large volume of fluids might be injected by this route ,hence it is suitable
for administration of saline solution.
Diluted irritant ,hypertonic solutions might be injected because drug
immediately diluted by blood
Absorption is not required
 No first pass effect takes place
 Blood plasma or fluids might be injected.
The desired blood conc. Of the drug can be obtained accurately and
immediately.
Advantages

28.  There is no retreat ---Side effects are quicker than other route
This method is more risky---needle should be inserted properly, no leaking from site
of injection ,Sepsis-Infection might occur.
e.g. Phlebitis(Inflammation of the blood vessel) might occur
Infiltration of surrounding tissues might result.
 This method is not suitable for oily preparations
 This method is not suitable for insoluble preparations
Injected drug into vein must be cautiously controlled and maintain.
E.g. iron,Aminophylline as high conc.of these drug in blood may be dangerous.
Disadvantages:

29. Intramuscular injection
Drug injected in muscle
Drug like soluble substances mild irritants, suspensions and
colloids.
Rapid absorption and even distribution
Volume of injection should be upto 10 ml

30. Advantages
Absorption is rapid than subcutaneous route.
 mild irritants,suspension ,colloids and injections with Oily
preparations can be used.
Slow releasing drugs can be given by this route.
Disadvantages
Using this route might cause nerve or vein damage
Produce local pain and abscess formation.
Total volume of drug injected is restricted up to 10 ml
Certain IM injections need more time for absorption e.g. IM
diazepam,Digoxine .

31. Subcutaneous
Drug Injected below skin
Subcutaneous route might be used for the arm, forearm, thigh and sub
scapular space.
Non irritant substances can be injected by this route.
The volume used is 2 ml.
Insoluble suspensions like insulin and solids might be applied by this
route.

32. Advantages:
• Absorption is slow and constant
• It is hygienic
Disadvantages:
• It might lead to abscess formation
• Absorption is limited by blood flow
Examples of drugs given by subcutaneous route include insulin, adrenaline

33. Hypo spray (jet injections) injection of
drug by high velocity jet projection gun
Hypodermolysis: injecting large amount
of drug through the loose subcutaneous
tissue of the body.
Padiatric practices saline solutions are
given by this route
Implants sustained and long acting slow acting drugs injected by
subcutaneous route act as “depot”
Last for 9 to 15 month by repeated injections

34. Intraarterial route
Drug injected into artery
Produced localized effect in particular organ or tissue
e.g.anticancer drugs are given by this route
 This method is used for chemotherapy in cases of malignant
tumors and in angiography.

35. Intrathecal route
 Intrathecal route involves the subarachnoid space.
 Injection may be applied for the lumbar puncture, for spinal anaesthesia
and for diagnostic purposes.
This technique requires special precautions.

36. Intraperitoneal route:
Drugs are injected into peritoneal cavity which offers a large absorbing
surface.
Employed in laboratories
Used in infants

37. Intra-Articular route
Intra-articular route involves injection into the
joint cavity.
Corticosteroids may be injected by this route in
acute arthritis.

38. Inhalation
• Inhalation may be the route of choice to avoid the systemic effects. In this
way drugs can pass directly to the lungs.
• Drugs used involve volatile drugs and gases.
• Examples include aerosols like salbutamol; steam inhalations include
tincture and Benzoin
Advantages:
• Rapid absorption
• Rapid onset of action
• This route has minimum side effects.
• No first pass effect
• This method is easy.
• Fewer doses is required.
Disadvantages:
• Special apparatus is required.
• Irritation of the respiratory tract may take place.
• Cooperation of the patient is required.