Transcript DOSAGE FORUM AND PRESCRIPTION WRITING

By the end of this session, you’ll
be able to:
 Identify
the various dosage forms
 Enumerate
the different routes of
drug administration
 Explain
the advantages and a
disadvantages of each form.
Drug Dosage Forms
Definition
Dosage Forms:
It is the pharmaceutical
preparation in which the drug is
administered to the patient.
Classification of
Drug Forms
Enteral Parenteral Inhalation Topical
Enteral dosage forms
Through GIT:
Rectal
OralSublingual
Oral
liquids
solid
Liquid preparations
1-aqueous:
1-Solution
2-Syrup
3-Emulsion
4-Suspension
5-Mixture
4-Decoction
6-Infusion
2-alcoholic
1-Tincture
2-Spirits
Advantages:
convenient,
economical, & safe.
FIRST PASS EFFECT
Disadvantages:
Not suitable in
1-unconscious.
2-excessive vomiting.
3-emergencies.
4-drugs destroyed by digestive
enzymes,or gastric acidity benzyl
penicillin.
5-drugs irritant to GIT.
6-drugs not absorbed from GIT.
7-drugs with very extensive first pass
metabolism..
Solid preparations
1-Tablets:
Simple.
Compressed
Sugar coated
Enteric coated
Sustained release
Effervescent
Sublingual.
2 - Capsules:
Hard Gelatin
Soft Gelatin
Enteric coated
Sustained release.
3 - Powder
In packets or in bulk.
4 - Effervescent
granules
In packets or in bulk.
Sublingual
1- Rapid
2- No first pass
3- Effect can be
terminated
4- Avoid GI T
enzymes.
Rectal
Suppository
Advantages:
1-Escape first pass
2-Avoid digestive
enzymes.
3-Avoid gastric
irritation.
4-Large volume of
fluids.
Enema
Parenteral
Subcutaneo
njections
I mplants
Ampoules.
Injections
Vials
Bottles.
Must be sterile and pyrogen free.
`
Means for parenteral
1-I ntravenous(IV):
Adv.:
Rapid
Large volume of fluids
Escape first pass metabolism.
Disadv:
1-Undesirable reactions due to rapid high
concentration.
2-Not suitable for oily preparations
3-Venous thrombosis
2- Intra-muscular (IM):
For aqueous or oily preparations
3-Subcutaneous(SC):
Non irritant drugs (aqueous).
4-Intrathecal
5- Intracardiac
6- Intra-arterial
7- Intra-articular
8- Intra-peritoneal
9-Bone Marrow
Subcutaneous Implantations
Pellet implanted
under skin to allow
release of the drug
over several weeks
or months.
Inhalation

Gas

Volatile liquids


Solution
administered as
AEROSOL
(Nebulizer).
Finely micronized
powder “Spinhaler”
Topical
For Local
Effect
Skin
Mouth
For Systemic
Effect
Ear
Eye
Vagina
Nose
Transdermal Delivery Patches
For systemic
effects
 Advantages:
Prolonged blood
levels
No 1st pass
effect.
Important
Info
The ROA is determined by the physical
characteristics of the drug, the speed
which the drug is absorbed and/ or
released, as well as the need to
bypass
hepatic
metabolism
and
achieve high conc. at particular sites
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Info!