Understanding Different Routes Of Drug Administration💊

I am exploring the Journey from Injection to Inhalation, revealing the Science Behind Drug Delivery Methods.

I’ve chosen to tell you about the routes of drug(medicines) administration which is indeed very important from the knowledge perspective in the field of medical medicine and pharmacy.

Introduction:

If I talk about the introduction, the route of administration is an important factor that influences the absorption of a drug. Here comes a word called ‘Biological Lag’ which is the interval between drug administration and the development of response.

Classification of routes:

The routes of drug administration can be classified as:

1. Oral or Enteral route: Tablet, Capsules, pills, etc
2. Parenteral route: Injection, Inhalation, Transcutaneous, etc
3. Local application: Creams, Ointment, paste, etc

Oral or Exteral route:

It is the most commonly used route for drug administration. This route has many advantages like it is a safe, convenient, and economical route, self-medication is possible, and withdrawal of the drug is possible but also has some disadvantages which include,

1. Slow onset of action
2. Drugs that are bitter in taste can not be administrated
3. Gastric enzymes may inactivate the drug
4. This route is not possible in an unconscious patient

Parenteral Routes:

Route of administration other than oral route are termed as parenteral.

Advantages of the parenteral route:

1. Absorption is rapid
2. accurate dose of the drug can be given
3. useful in emergency
4. useful in the case of an unconscious patient

Disadvantages:

1. Pain may be produced by the injection
2. It is an expensive route
3. Self-medication is not possible
4. Abscess and inflammation at the injection site

A.Injection

Intradermal:

The drug is administrated in the layers of the skin. e.g. BCG vaccine

2. Subcutaneous:

Subcutaneous injections are used to administer medications between skin and muscle.

3. Intravenous(IV):

A drug is directly injected into a vein.

4. Intra arterial:

A drug is injected into an artery. eg. Anticancer drugs are sometimes administrated by this route.

5. Intraperitoneal:

A drug is injected into the perineal cavity.

B. Inhalation

Gases, Volatile liquids, Aerosols, or Vapours can be administrated by this route.

C. Transcutaneous

It is further divided as,

1. Iontophoresis
2. Inunction
3. Jet injection
4. Adhesive units

1. Iontophoresis:

In this method, a drug is driven deep into the skin by means of a galvanic current e.g. Salicylates.

2. Inunction:

It is rubbing the drug on the skin. The drug gets absorbed and produces systemic effects. e.g. nitroglycerine ointment for angina

3. Jet injection:

This method does not require a syringe. So it is painless. Using a gun-like instrument with a microfine orifice, the drug solution is projected as a high-velocity jet. This method is useful for mass inoculation.

4. Adhesive units:

It is a transdermal drug delivery system(TDDS). It is available in the form of an adhesive unit. It delivers the drug slowly. So it produces a prolonged systemic effect e.g. scopolamine for motion sickness.

D. Transmucosal route

It is further divided as,

1. Sublingual
2. Trans nasal
3. Trans rectal

1. Sublingual route:

A tablet containing the drug is put under the tongue and allowed to dissolve in the mouth e.g. nitroglycerine and isoprenaline.

2. Trans nasal:

It is useful for drugs in the form of snuff or nasal spray. The drug is readily absorbed through the mucous membrane of the nose. e.g. posterior pituitary powder.

3. Trans rectal:

Drugs can be absorbed through the rectum to produce systemic effects. e.g. aminophylline for bronchospasm, and diazepam for status epilepticus.

E. Special drug delivery systems:

1. occusert:

It is placed directly under the eyelid. It can release drugs like pilocarpine for prolonged periods.

2. Progestasert:

It is an intrauterine contraceptive device. It produces a controlled release of progesterone within the uterus for a year.

3. Prolong:

It is an inactive drug that after administration is metabolized into an active drug. for example, L-dopa is an inactive compound. After administration, it is metabolized to the active drug dopamine which is effective against Parkinsonism.