1.Introduction to parenterals and Routes of parenteral administration.ppt

The term parenteral is derived from the Greek words para (meaning “outside”) and enteron (meaning “intestine”). Thus, parenteral administration refers to routes of drug delivery that bypass the gastrointestinal (GI) tract. This method is particularly important for drugs that are poorly absorbed, unstable in the GI environment, or rapidly metabolized when administered orally. Parenteral dosage forms deliver medications directly into the body tissues or circulatory system using sterile techniques and specialized dosage forms.

Parenteral products are critical in clinical settings where rapid onset of action, precise dosing, and systemic effects are essential — for example, in emergencies, critical care, and situations where patients cannot take medications orally (such as unconscious or vomiting patients).

1. Routes of parenteral administration

5. Route of
Administration

6. •Intracutaneous or intradermal injections
•This is given into the skin between inner layer dermis and
outer layer epidermis. Volume can be 0.1 to 0.2 ml. This route
is mainly used for diagnostic purposes. In investigation of
immunity and allergy. E.g. Mantoux test injection for
diagnosis of tuberculosis.
•Subcutaneous or hypodermic injections
•These are made under the skin into subcutaneous tissue. The
volume injected is 1 ml or less usually given injection in
upper arm. This is most popular route as it is convenient for
patient and doctor.

7. Intramuscular injections
These are made into a muscle passes through the skin, subcutaneous tissue,
membrane enclosing the muscle. Volume 2 to 4 ml. Aqueous or oily
suspensions and oily solutions can not be given subcutaneously as blockage of
small blood vessels may occur. Painful injections should be administered
slowly.
Intravenous injections:
These are made into a vein and therefore are introduced directly into the blood
stream. Median basilic vein is selected as it can be easily located. Volume
injected varies from 1 ml to 500ml.infusion fluids are given. Eg.Normal saline
solution or dextrose solution.
Intra arterial injections: Injection of drug into an artery is a random event. It
may be accidental or associated with drug abuse. At first sight it appears
puzzling because the simple expedient of withdrawing blood into the syringe
prior to an ‘IV’ injection should preclude its occurrence. The brachial artery is
the commonest site of accidental injection.

8. •Intra cardiac injection:
•These are given into the heart muscle or ventricle in an emergency
only. To improve heart rate. Eg. Adrenaline and isoprenaline
injection.
•Intrathecal injection:
•These are made into subarachnoid space that surrounds the spinal
cord. Spinal anasthesia.
•Intracisternal injection: The intracisternal route
involves
 administration of a drug directly intothe cerebrospinal
fluid of the brain ventricles. It could be
 performed by
 
direct injection  into the cisterna magna or via permanently
positioned tube.

9. •An epidural injection:
•It provides temporary or lasting relief from pain or
inflammation in the spine or extremities (arms and legs).
Imaging guidance may be used to place the needle in the right
location for maximum benefit. The injection may also help
confirm the exact site of the pain.
•Intra-articular injection:
•It  
is a type of shot that's placed directly into a joint to relieve
pain. Corticosteroids (steroids), local anesthetics, hyaluronic
acid, and Botox are the most common substances
 injected into
joints for this treatment.