enteron: intestine (i.e. beside the intestine)
These are the preparations which are given
other than oral routes.
Pyrogen free preparations intended to be
administered parenterally (outside
Parenteral preparation or injectables are the
sterile solutions or suspensions of drug in
aqueous or oily vehicles meant for introduction
into the body by means of an injection under or
through one or more layers of the skin or mucous
•Based on types of packaging
1)Single dose units: ampoules, infusions and
prefilled disposable syringes
2)Multiple dose units: multiple dose vials
•Based on the production and control
a)Small volume parenterals: volume < 100 ml
b)Large volume parenterals: volume ≥ 100 ml
Classification of parenteral preparations
•Based on clinical use
a)Solutions for irrigation
•Based on physical state of product
Small volume parenterals:
Volume of these parenterals varies from fractions of
Milli liter to several hundred milliliters i.e. 1ml to 500ml
Example: Injections :- Furosemide, Heparin, Cimetidine,
Iron dextran etc
Large volume parenterals:
Volume of these parenterals varies from 500ml and above.
They are administered as single dose injections at a slow rate.
Example: Infusion Fluids, Total parenteral nutrition solutions,
patient controlled anlgesia, dialysis fluids etc.
Parenteral Route Is Used bcoz
1) Rapid action
2) Oral route can not be used
3) Not effective except as injection
4) Many new drugs particularly those derived
from new development in biotechnologically
can only be given by parenteral coz they are
inactivated in GIT if given orally.
5) New drugs require to maintain potency &
specificity sodium that they are given by
Quick onset of action
Suitable for the drugs which are not administered by
Useful for unconscious or vomiting patients.
Duration of action can be prolonged by modifying
Suitable for nutritive like glucose & electrolyte.
Suitable for the drugs which are inactivated in GIT or
HCl (GI fluid)
Once injected cannot be controlled (retreat)
Injections may cause pain at the site of injection
Only trained person is required
If given by wrong route, difficult to control adverse
Difficult to save patient if overdose
Sensitivity or allergic reaction at the site of injection
Requires strict control of sterility & non pyrogenicity
than other formulation.
Necessities of Parenteral preparations:
Free from particulate matter (must)
Solvents or vehicles used must meet special purity and
Restrictions on buffers, stabilizers, antimicrobial
preservative. Do not use coloring agents.
Must be prepared under aseptic conditions.
Specific and high quality packaging.
Routes of Parenteral Administration
Subcutaneous (SC; SQ ;Sub Q):
The injection is given under the skin
Need to be isotonic
Upto 2 ml is given
Using ½ to 1 inch 23 gauge needle or smaller needle
Striated muscle fibre
0.5 to 2 ml sometimes upto 4 ml
1 to 1.5 inch & 19 to 22 gauge needle is used
Deltoid (upper arms)
Vastus lateralis (lateral thigh)
Into the vein
1 to 1000 ml
1 inch ,19 to 20 gauge needle with injection rate
1ml/ 10 sec. for volume upto 5 ml & 1 ml/ 20 sec.
for volume more than 5 ml.
Hydro alcoholic solutions
IV infusion of large volume fluids (100- 1000
ml) has become increasingly popular. This
technique is called as Venoclysis.
This is used to supply electrolytes & nutrients
to restore blood volume & to prevent tissue
Combination of parenteral dosage forms for
administration as a unit product is known as
an IV admixture.
Lactated Ringer Injection USP
NaCl Injection USP (0.9 %)– (replenish fluid &
Dextrose Injection USP (fluid & electrolyte)
Direct into the artery
2 to 20 ml
20 to 22 gauge
Solutions & emulsions can be administered
Radio opaque media
Also called intra-spinal
Directly given into the spinal cord
1 to 4 ml
24 to 28 gauge
Must be isotonic
Given directly into the joints
2 to 20 ml
5 inch 22 gauge
Must be isotonic
Given directly into the pleural cavity or lung
Used for fluid withdrawal
2 to 30 ml
2 to 5 inch, 16 to 22 gauge needle
Directly given into the heart
0.2 to 1 ml
5 inch , 22 gauge needle
Calcium salts as a calcium channel blockers
Also called as diagnostic testing
½ inch, 25 to 26 gauge needle
Should be isotonic
Official Types of Injections:
1. Solutions of Medicinal
Example: Codeine Phosphate Injection
2. Dry solids or liquid concentrate does not contain
Example: Sterile Ampicillin Sodium
3. If diluents present, referred to as.....for injection
Example: Methicillin Sodium for injection
Parenteral drugs are formulated as solutions, suspensions,
emulsions, liposomes, microspheres, nanosystems and
powders to be reconstituted as solutions.
Formulation mainly consists of two components
1.water for injection
2.sterile water for injection
3. bacteriostatic water for injection
2. Non-aqueous vehicles
water miscible vehicles
water immiscible vehicles
a. It is most frequently used in the large scale manufacturer of
b. Water of suitable quality for compounding and rinsing product
contact surfaces may be prepared either by distillation method
or reverse osmosis, to separate adequately various liquid, gas,
and solid contaminants and undissociated substances such as
pyrogens present in the absence of ions from water.
c. It is not required to be sterilized and pyrogen free.
d. It is intended to be used within 24 hours after collection.
e. The water should be collected in sterile and pyrogen free
f. It contains total solid contents not more than 1 mg/100 ml.
Water for injection:
Sterile water for injection:
a.It must be pyrogen free but an allowable endotoxin level is not
more than 0.25 USP endotoxins units per milliliter.
b.It may not contain any added substance like antimicrobial agent.
c.It is packed in single dose containers not larger than 1 liter.
d.This water is intended to be used as solvent, vehicle or diluent for
already sterilized and packaged injectable medications.
e.It is mainly used for reconstitution of multiple antibiotics.
f.It contains more slightly more total solid contents than the water
for injection because of the leaching of solids from the glass lined
tanks during sterilization.
a. It is sterile water for injection containing one or more
suitable antimicrobial agents.
b. It is packaged in prefilled syringes or in vials
containing not more than 30 ml of the water.
c. It is used as a sterile vehicle in the preparation of
small volumes of the injectable preparations ( in large
volumes, excessive and toxic amounts of
bacteriostatic agents such as benzyl alcohol may
cause gasping syndrome(multiorgan failure)).
d. Presence of bacteriostatic agent in small volumes may
provide flexibility for multiple-dose vials.
e. This water is specifically labeled as per the USP
requirements as “NOT FOR USE IN NEONATES”.
Bacteriostatic water for injection:
1.Total solids content- a gravimetric evaluation of the
dissociated and undissociated organic and inorganic
substances present in the water.
2.Electrolytic measurement of the conductivity- immersing
electrodes in the water and measuring the specific
conductance, a measurement that depends on the ionic
content of water.
Conductance may be expressed by the meter scale as
1.conductivity in micromhos
2.resistance in megohms
3.ionic content in ppm of sodium chloride
Water for injection should not have a conductivity of more
than 1 micromho, 1 megohm and approximately 0.1 ppm
Quality tests for Water for Injection:
a) These are mainly used to eliminate water entirely or impart from the
vehicle, primarily because of the solubility factors or hydrolytic reactions.
b) It must be non-irritating, non-toxic or non-sensitizing and it must not
exert an adverse effect on the ingredients of the formulation.
c) It must not exert a pharmacological activity of its own and it may not
adversely affect the activity of the medicinal agent.
d) It physical and chemical stability at various pH levels
e) It has sufficient viscosity which must be such as to allow ease of injection.
f) It has Fluidity, which must be maintained over a fairly wide temperature
g) It has a Boiling point, which should be sufficiently high to permit heat
sterilization, miscibility with body fluids and low vapor pressure to avoid
problems during heat sterilization.
Two types of solvents are mainly used in combination with water are
1.water miscible solvents
2.water immiscible solvents
Water miscible solvents Water immiscible solvents
Dioxolanes Fixed oils
Dimethylacetamide corn oil
N-(β-hydroxyethyl)-lactamide cottonseed oil
Butylene glycol peanut oil
Polyethylene glycol 400 and 600 sesame oil
Propylene glycol Ethyl oleate
Glycerin Isopropyl myristate
Ethylalcohol Benzyl benzoate
a.The most commonly used solvents are Polyethylene glycol,
Propylene glycol and fixed oils.
b.Ethyl alcohol (40% ethanol with water) is particularly used in
the preparation of solutions of cardiac glycosides.
c.Glycols are mainly used in the solutions of barbiturates, certain
alkaloids and certain antibiotics.
d.The fixed oils must be of vegetable origin so that they will be
2.liquid at room temperature
3.not become rancid readily
4.clear when cooled to 10°C to ensure the stability and clarity
of the injectable product during refrigeration.
5.Not contain mineral oil or paraffin, as these are not
absorbed by body tissues.
6.Having saponification value between 185 and 200 and an
iodine value between 79 and 141
I)All substances added to the preparation must improve its quality.
II)An added substance may
•Increase and maintain drug solubility. Examples include
complexing agents and surface active agents.
1.Complexing agents include cyclodextrins, mainly Capsitol.
2.Surface active agents include :
polyoxyethylene sorbitan monolaurate (Tween 20) and
polyoxyethylene sorbitan monooleate (Tween 80).
2. Provide patient comfort by reducing pain and tissue irritation.
Tonicity modifiers such as sodium chloride, dextrose and glycerin.
3. Enhance the chemical stability of a solution. Examples are
gases, chelating agents and buffers.
Solutes or added substances:
4. Enhance the chemical and physical stability of a freeze-
dried product. Examples
are cryoprotectants and lyoprotectants.
5. Enhance the physical stability of proteins by
minimizing self aggregation or
interfacial induced aggregation. Examples include
6. Minimize protein interaction with inert surfaces
such as glass, rubber and plastic
by adding competitive binders such as albumin and
surface active agents to the
1.Protect a preparation against the
growth of micro organisms. Examples
1.Sustaining or controlling the drug
release by using controlled release
2.Maintaining the drug in a
suspension dosage form by using the
suspending agents includes polymers
and surface active agents.
3.Maintaining the drug in an
emulsified dosage form by using the
emulsifying agents includes
amphiphilic polymers and surface
4.Useful in the preparation of
liposomes by using hydrated
2. Melting point
4. Surface characteristics
6. Partition coefficient
8. Bulk density and powder flow