Basics Of Pharmacy: Basics Of Route of Drug Administrations

Saturday, October 23, 2021

Basics Of Route of Drug Administrations

Route of drug administration is the path that is used to deliver drugs into the body to treat,  cure or prevent the occurrence of disease. As the name indicates route means paths so basically route of drug administration is the route or path which is followed by the drug to reach its site of action.

Selection of suitable Route of drug administration plays an important role for patient health because the onset of drug action and bioavailability of the drug is greatly dependent on the drug route and the route may be selected on the following basis,

  • Ease Of the Patient/Age of patient

  • Nature of the drug

  • Patient Condition

  • Required Onset of action

  • Pharmacokinetics & Pharmacodynamics

Ease Of Patient/Age of patient

  • Ease of the patient means which route is comfortable for the patient.  For example,  the oral route is not suitable for those patients who have difficulty in swallowing.

Nature of the drug

Selection of drug route administration is also dependent on the nature of drugs, this mean nature of some drugs is such that those can only be administered by a specific route like insulin.

Patient Condition

The selection of drug route administration is also dependent on the condition of the patient.

If Patient is suffering from nausea and vomiting. The oral route is not recommended.

Required Onset Of Action

  • The selection of the route of drug administration is also dependent on the  drug onset of action.

  • For example,if  delayed  release action   is required then it can be administered in the controlled release tablet by oral route.

Classification Of Drug Routes

The action of a drug may be required locally on a specific site or it can be used for systemic effect. Based on the above-mentioned requirement there are two main factors for the classification of drug routes,

  • Local effect 

  • Systemic Effect

Following are main routes for drug administration,

  • Enteral Route

  • Parenteral Route

  • Topical

  • Transdermal

  • Inhalation

Enteral Route

The enteral route of administration  is the type of drug administration route in which the drug is administered to the body through GIT.

We can use both ends of GIT for the enteral route meaning the drug may be administered through the mouth or by rectal route as well.

Enteral Route is further divided into following,

  • Oral(Per Oral),  PO

  • Sublingual

  • Rectal Route

Oral Route Of Administration

The oral route of administration is one of the most commonly used routes for drug administration and in this route drugs are in the form of a tablet, capsule,  pills, syrup or  suspension and are taken by mouth.

Benefits of Oral Route

Following are some major benefits or advantages of the oral route,

  • Oral administration is cheapest route

  • Patient Acceptance is high

  • Easy to administer

  • Safe to use 

  • No device is required to administer

Disadvantages Of Oral Route

Following are some drawbacks of the oral route

  • Not suitable for patients suffering from nausea and vomiting.

  • Not suitable for unconscious patients.

  • Bioavailability is low due to the first-pass effect.

  • Food may interact with drugs.

  • Objectionable, due to bitter taste.

Sublingual Route/Buccal Route

The sublingual route is the route of drug administration in which the drug is placed below the tongue or in between gums and gingiva.

In the sublingual or buccal route, the drug is absorbed through the mucosa into the circulation.

  • The sublingual route provides fast dissolution of drugs.

  • The first pass effect is prevented.

  • Not suitable for bitter drugs.

  • Nitroglycerine is a common example of a drug administered through this route.

Rectal Route

The rectal route is also an important route for drug administration and is used for local and systemic effects.

In the rectal route,  drugs are absorbed through the rectal mucosa.

  • This route can be  used for unconscious patients.

  • The drugs which are irritating to the stomach can be administered through this route.

  • Suppositories and enemas are dosage forms that are administered through this route.

  • The patients suffering from nausea and vomiting are good candidates for this route.

Parenteral Route

Parenteral is derived from the Greek word "para" which means beside and "enteral" means intestine so the parenteral definition is as follow,

Drug administration other than GIT.


The parenteral route or parenteral meaning is the route of drug administration other than intestine,it is also known as injection route.

  • Bioavailability through the parenteral route is highest because through this route the first-pass effect is bypassed.

  • The fastest onset of drug action is achieved through this route because usually in the case of the IV route drug is directly administered into the blood circulation.

Types Of Parenteral Route

The parenteral route is further divided into the following,

  • Intravenous Route (IV)

  • Intramuscular Route (IM)

  • Subcutaneous Route (SC)

Intravenous Route (IV)

  • In the IV route drug is directly administered into the veins.  This route provides rapid drug action and can be used in emergency conditions.

Intramuscular Route (IM)

In this route, drugs are injected into the muscles of the body.

Subcutaneous Route (SC)

It is the route in which drugs are  injected below the skin.

Above mentioned are three most commonly used parenteral routes, other parenteral routes which are not  widely used are as follow,

  • Intraspinal Route

  • Intrathecal Route

  • Intra-Arterial Route (IA)

  • Intraperitoneal Route (IP)

  • Intracardiac Route

  • Intracerebroventricular

Topical Route

The topical route is the route in which drugs are applied to the skin surface mucous membrane or into body cavities like the ear,  nose, eyes etc

Topical route is further subdivided into the following,

Epidermic Route

  • In the epidermal route, a drug is applied to the skin by rubbing into the skin.

Enepedermic Route

  • In this route,drugs are applied to outer   skin surfaces in the form of creams or ointments etc.


  • In this route the drug in finely divided powders are applied to the body cavities.


  • In irrigation, the cavities of the vagina, uterus,  and urethra are washed with antiseptic fluids.

Transdermal Route

  • In the transdermal route, the drug in the form of patches is applied to the skin and the drug is absorbed.

  • This route is used for lipophilic drugs.

  • Transdermal medications are administered through the skin in the form of patches of different drugs.

Inhalational Route

  • In this route drug in form of aerosols or fine powders is administered through inhalation and directly reaches to the lungs.

  • This route is used for both local and systemic effects.

  • Usually, this route is used for asthmatic patients for rapid action.

Also Read:

Pharmacology And Its Branches

Basics Of Pharmacognosy

No comments:

Post a Comment