Any route other than oral, sublingual, buccal or
rectal is considered a parenteral route
The term parenteral means next to, or beside, the
enteral. It refers to any sites of administration that
are outside of or beside the alimentary tract
Intraocular
Volume of tears: 7 microliters
Hold up to 10 microliters without spillage
Eyedropper dispenses 50
microliters hich means
80% of a dose will be lost
from the eye overflow
Rate of tear production:
2 microliters/minute
Tear volume in the eye turns
over every 2-3 minutes
Ophthalmic ointment
tubes hold approximately
3.5 g of ointment
Intranasal
Nasal cavity capacity: 20ml
Most common use is for decongestant activity
Should not be used for prolonged periods
Inhalation
Metered dose inhaler (MDI)
Delivers a fixed dose when
the aerosol is actuated
Adapter and Spacers
Allows the patient to coordinate
inhalation and actuation of the aerosol
Dry powder inahler
Device automatically
releases the drug when
the user inhales
The powdered drug is supplied in hard gelatin
capsules, cartridges, or foil blister strips, and is
loaded into the inhalation device
Atomizers and Nebulizers
Device breaks up a liquid into a spray
Dermal
Most dermal dosage forms are used for local effects on or within the skin
Ointments, creams, and lotions are the most popular dermal formulations
Collodions: liquid preparations of proxylin dissolved in a solvent mixture of
alcohol and ether. Looks like raw cotton and is slowly but completely soluble in
the solvent mixture. When applied to the skin, the solvent rapidly evaporates,
leaving a protective film on the skin that contains a thin layer of the drug
Liniments: alcoholic or oleaginous solutions generally applied by rubbing
Dermal aerosols are generally used to apply
anesthetic and antibiotic drugs for local effect
Vaginal
Avoids degradation that occurs with oral administration; doses can be retrieved if
necessary; and it has the potential of providing long term drug absorption
Suppositories are used as contraceptives, feminine hygiene antiseptics,
bacterial antibiotics, or to restore the vaginal mucoas
Parenteral routes are some times preferred when a rapid drug
response is desired, as in an emergency, or when the patient is
uncooperative, unconscious, or otherwise unable to take a drug by
an enteral route
Disadvantages
Cost more than enteral route
Require skilled personnel to administer them
Once administered, it is most difficult to remove
the dose if there is an adverse or toxic reaction
Injections
Intravenous
Needle gauge: 16-20
Large needle gauge
Needle length 1-1.5"
May be large volume, slow infusion
Intramuscular
Needle gauge: 19-22
Needle length: 1-1.5"
Slower onset but longer duration
of action compared to IV
Z-tract injection
Intradermal
Needle gauge: 25-26
Small needle gauge
Needle length: 3/2"
Injected into the top layer of skin at a slight angle
Subcutaneous
Provides slower absorption compared to IM, but
faster absorption compared to oral administration