Dosage Formulations and Routes of Administration
6
Sources of DrugsSources of Drugs
• Natural drug sources Occur in nature and are naturally
occuring Derived or extracted from plants,
animals, and minerals
Sources of DrugsSources of Drugs
• Natural drug sources Plant sources include:• Acetylsalicyclic acid (aspirin) derived
from white willow bark• Cocaine derived from the coca plant• Codeine and morphine derived from the
opium poppy plant
Sources of DrugsSources of Drugs
• Natural drug sources Animal sources include:• Bovine insulin derived from cow pancreas• Porcine insulin derived from pig pancreas• Pepsin derived from cow stomach• Thyroid hormones derived from pig
thyroid gland
Sources of DrugsSources of Drugs
• Natural drug sources Mineral sources include:• Ferrous sulfate (iron) to treat iron
deficiencies• Gold used to treat arthritis• Magnesium for milk of magnesia (laxative
and antacid)
Sources of DrugsSources of Drugs
• Natural drug sources Mineral sources include:• Potassium to supplement low potassium
levels• Sodium chloride is common base solution
for IV therapies• Zinc for skin protectants and sunscreen
Sources of DrugsSources of Drugs
• Synthetic drug sources Produced in a laboratory, not naturally
occuring Semisynthetic: naturally occuring
substance that has been chemically altered
Synthesized: made in laboratory to imitate a naturally occurring drug
Sources of DrugsSources of Drugs
• Synthetic drug sources Examples of synthetic drugs• Adrenalin• Synthesized epinephrine for treating
hypersensitivity and asthma attacks• Amoxicillin, ampicillin, and piperacillin• Semi-synthetic pencillins to treat various
infections
Sources of DrugsSources of Drugs
• Synthetic drug sources Examples of synthetic drugs• Barbiturates• Synthetic CNS depressants
• OxyContin• Synthetic opiate for pain management
Sources of DrugsSources of Drugs
• Genetically engineered drug sources Recombinant DNA• Combining two different DNA strands to
produce a new strand of DNA or rDNA • Human insulin created to treat diabetes• Recombinant hepatitis B vaccine
Sources of DrugsSources of Drugs
• Genetically engineered drug sources Monoclonal antibodies (MAbs)• Hybrid cells created in laboratory from
animals; used to treat tumors and diagnose various conditions• Rituxan, Zevalin, Erbitux, Avastin: used in
the treatment of various cancers
Drug NomenclatureDrug Nomenclature
• Chemical name Reflects the chemical structure of the
compound Often long and hard to remember and
pronounce Named according to guidelines from the
International Union of Pure and Applied Chemistry (IUPAC)
Used primarily in research settings
Drug NomenclatureDrug Nomenclature
• Generic name Convenient and concise Assigned by manufacturer in
collaboration with the FDA Not capitalized May be used by anyone—not restricted
by copyright or tradmark Used in the USP and the USP-NF
Drug NomenclatureDrug Nomenclature
• Trade or brand name Registered or trademarked by a specific
producer or manufacturer to identify its particular drug
This name cannot be used by other manufacturers but a generic may be sold under more than one trade name.
Usually capitalized Also called the "proprietary name"
Classification of DrugsClassification of Drugs
• Classifications based on: Chemical ingredients Method by which the drug is used Area of the body that is treated
• Two usual classification methods Therapeutic use Mechanism of action
Dosage FormulationsDosage Formulations
• Dosage forms How medication is prepared for
administration to the patient Solid or liquid Single medication may be available in
multiple dosage forms for use at various disease states, patient ages, and desired results.
Dosage FormulationsDosage Formulations
• Solid dosage forms Most widely available form Can be administered orally, rectally,
vaginally, or topically Advantages and disadvantages
Dosage FormulationsDosage Formulations
• Solid dosage forms Tablets• Small formed shapes usually taken by
mouth• Active and inert ingredients work
together to ensure tablet is easy to swallow, taste, digestible, and releases drug at proper time.
Dosage FormulationsDosage Formulations
• Solid dosage forms Tablets• Molded tablets made with mold and wet
materials• Compressed tablets formed by die-
punching compressed, powdered, crystalline, or granular substances into a uniform shape, usually has a film, sugar coating, or enteric coating
Dosage FormulationsDosage Formulations
• Solid dosage forms Tablets• Caplets are film-coated tablets in the
shape of a capsule.• Chewable tablets should be chewed for
desired results.• Effervescent tablets dissolve in liquid
before administration.• Fast dissolving tablets can be taken orally
without water.
Dosage FormulationsDosage Formulations
• Solid dosage forms Tablets• Sublingual tablets disintegrate and are
absorbed under the tongue.• Buccal tablets disintegrate in the buccal
pouch, between the gums and the cheek.• Vaginal tablets are dissolved and
absorbed through the mucous lining of vagina.
Dosage FormulationsDosage Formulations
• Solid dosage forms Capsules have drug contained in a shell• Soft gelatin shells are soft and elastic,
flexible during administration, and can't be broken apart.• Hard gelatin shells have two oblong
halves joined together, which can be separated if necessary.
Dosage FormulationsDosage Formulations
• Solid dosage forms Lozenges (also called pastilles or
troches)• Hard, disk-shaped solid form in a sugar
base• Remains in the patient's mouth until has
been completely dissolved and all medication releases
Dosage FormulationsDosage Formulations
• Solid dosage forms Powders• Usually produced in large supplies for
bulk compounding• Can be used internally or externally• Individual doses packaged in a powder
paper
Dosage FormulationsDosage Formulations
• Solid dosage forms Granules• Made from wetted then dried powders
ground into course, nonuniform particles• Commonly used in pediatric antibiotic
suspensions• Dissolved in distilled water
Dosage FormulationsDosage Formulations
• Solid dosage forms Medicated sticks• For topical application of local
anesthetics, sunscreens, antivirals, antibiotics, and cosmetics
Dosage FormulationsDosage Formulations
• Semisolid dosage forms Suppositories • Administer medication via rectum, vagina,
or urethral tract• Melt or dissolve at body temperature• Used for babies and other instances where
oral dosing may not be practical Creams may or may not contain
medication; oil-in-water or water-in-oil bases.
Dosage FormulationsDosage Formulations
• Semisolid dosage forms Ointments are applied externally to the
skin or mucous membranes.• Oleaginous ointments: emollients to
soothe and cool. Hydrophobic, meaning not easy to wash off.
Dosage FormulationsDosage Formulations
• Semisolid dosage forms Ointments are applied externally to the
skin or mucous membranes.• Water-soluble ointments: contain no fat
or water, easily wash off. Can be mixed with nonaqueous or solid medication• Anydrous ointments: absorb water,
turning into a water-in-oil emulsion
Dosage FormulationsDosage Formulations
• Semisolid dosage forms Ointments are applied externally to the
skin or mucous membranes.• Emulsions• Emollient bases made of water-in-oil
(occlusive) or oil-in-water (nonocclusive)• Pastes• Stiff or very viscous ointments that do not
melt or soften at body temperature; usually contain at least 20% solids
Dosage FormulationsDosage Formulations
• Liquid dosage forms Solutions• Medication is completely dissolved and
evenly distributed (homogeneous) and quickly absorbed• Aqueous solutions use purified/sterile
water as vehicle for douches, irrigating solutions, enemas, washes, and sprays.
Dosage FormulationsDosage Formulations
• Liquid dosage forms Solutions• Viscous aqueous solutions use
purified/sterile water; thick, sticky—either liquid or semisolid; syrups, jellies, and mucilages.
Dosage FormulationsDosage Formulations
• Liquid dosage forms Solutions• Nonaqueous solutions don't use water,
usually alcohol, glycerin, or propylene glycol.
Dosage FormulationsDosage Formulations
• Liquid dosage forms Solutions• Hydro-alcoholic solutions use alcohol and
water as vehicle or dissolving agent. Example:• Elixirs: liquid preparations with flavored
water and alcohol mixtures for oral administration. Many drugs dissolve more easily this way. Range of alcohol contents varies from 2–30%.
Dosage FormulationsDosage Formulations
• Liquid dosage forms Solutions• Hydro-alcoholic solutions use alcohol and
water as vehicle or dissolving agent. Example:• Aromatic elixirs are nonmedical, used to
mask unpleasant medicine taste.
Dosage FormulationsDosage Formulations
• Liquid dosage forms Solutions• Alcoholic solutions use no water, usually
ethyl or ethanol alcohols.• Collodions contain pyroxylin, applied to
skin, can carry an added medication• Spirits contain volatile and aromatic
substances, administered internally or inhaled.
Dosage FormulationsDosage Formulations
• Liquid dosage forms Solutions• Alcoholic solutions use no water, usually
ethyl or ethanol alcohols.• Glycerite contains medication dissolved in
glycerin, then is mixed into a water or alcohol vehicle, often has viscous, jelly-like consistency, rarely used today.
Dosage FormulationsDosage Formulations
• Suspensions Contain very fine solid particles mixed
with gas, liquid, or solid Break down faster than tablets or
capsules Must be shaken well before use
Dosage FormulationsDosage Formulations
• Suspensions Usually intended for oral ingestion
where large amount of medication is needed.
Other routes• Ophthalmic, parenteral, otic, and rectal
Dosage FormulationsDosage Formulations
• Suspensions Magmas and milks• Suspensions of undissolved medications
in water Lotions• For external use only
Dosage FormulationsDosage Formulations
• Suspensions Gels• Similar to magmas and milks but
particles are smaller, used for oral or topical administration
Extractives• Drug extracted by soaking dried plant or
animal tissue in solvent
Dosage FormulationsDosage Formulations
• Suspensions Tinctures• Extractive alcoholic and hydro-alcoholic
solutions; each mL of tincture = 100 mg of crude ingredient
Fluidextracts• More potent than tinctures; each mL =
1,000 mg of crude drug
Dosage FormulationsDosage Formulations
• Suspensions Extracts• Similar to tinctures and fluidextracts but
potency of crude drug is 2–6 times stronger
Dosage FormulationsDosage Formulations
• Emulsions Mixtures of water and oil (which
normally do not mix) Internal phase: one liquid broken into
small elements External (or continuous) phase: the
other liquid remains liquid Emulsifying agent added to keep two
liquids from seperating
Dosage FormulationsDosage Formulations
• Liniments Applied to skin with friction and rubbing Can be solutions, suspensions, or
emulsions Contain medication that mildly irritates
skin, producing counterirritation or inflammation to relieve inflammation of deeper tissues or muscles
Ben-Gay most common OTC liniment today
Dosage FormulationsDosage Formulations
• Transdermal patches Medicated adhesives that deliver
medication directly into bloodstream through the skin
Prescription and OTC applications• Sprays
Pump-type dispenser delivers medication nasally or translingually for quick absorption and onset
Dosage FormulationsDosage Formulations
• Inhalants Fine powder or solution delivered as
mist into nose or mouth, immediately entering respiratory tract
Asthma inhalers and allergy nasal sprays
Dosage FormulationsDosage Formulations
• Aerosols Very fine liquid or solid particles mixed
in vehicle, packed with gas and pressure, administered via respiratory tract or topically
Delayed and Extended ReleasesDelayed and Extended Releases
• Medications released over a period of time Extended release (ER) Long acting (LA) Sustained release (SR) Time release (TR) Controlled release (CR)
Routes of AdministrationRoutes of Administration
• Method by which medication is introduced into the body for absorption and distribution
• Varies from patient to patient Factors include patient's age,
consciousness, medical condition, time to achieve results, and side effects.
Routes of AdministrationRoutes of Administration
• Oral Abbreviation: PO (per os, Latin for "by
mouth") Advantages• Safe, convenient, easy to store; readily
available; lower cost, immediate release or extended release; easy to self-administer
Routes of AdministrationRoutes of Administration
• Oral Disadvantages• Hard to swallow for those who are
children, elderly, unconscious, ventilated, or having digestion problems• Take longer to absorb and distribute
Routes of AdministrationRoutes of Administration
• Oral Sublingual• Tablets administered under the tongue,
bypassing the digestive system and diffusing directly into the blood supply
Buccal• Tablets and lozenges/troches
administered between the gum and cheek, absorbed into bloodstream through mucous membranes
Routes of AdministrationRoutes of Administration
• Transdermal (percutaneous) Generally uses patch applied to skin Delivers medication to bloodstream Two kinds of patches• One controls rate of delivery to skin and
bloodstream• One lets skin control rate of delivery
Routes of AdministrationRoutes of Administration
• Inhalation Medication inhaled through mouth
directly into lungs Effective for lung conditions when
immediate relief is needed• Nasal
Inhaled through nose and absorbed into the bloodstream
Sprayed into nose for local effects
Routes of AdministrationRoutes of Administration
• Parenteral Medication does not pass through the
gastrointestinal system. Quicker absorption and distribution Convenient for those who cannot take
medicine orally Varied rate of delivery Dosage must be correct because action
is immediate and unreversable.
Routes of AdministrationRoutes of Administration
• Parenteral Intradermal (ID)• Injection into top layers of skin
Subcutaneous (SC)• Injection into tissue under the skin
Routes of AdministrationRoutes of Administration
• Parenteral Intramuscular (IM)• Injection into large muscle masses, such
as upper arm, thigh, buttock Intravenous (IV)• Medication administered directly into
vein
Routes of AdministrationRoutes of Administration
• Parenteral Other parenteral routes include:• Implant• Device inserted into the body to slowly
release medication• Intra-arterial• Injection into artery
• Intra-articular• Injection within joint
Routes of AdministrationRoutes of Administration
• Parenteral Other parenteral routes include:• Intracardiac• Injection into heart
• Intraperitoneal• Injection into abdominal or peritoneal
cavity• Intrapleural• Injection into sac (pleura) surrounding
lungs
Routes of AdministrationRoutes of Administration
• Parenteral Other parenteral routes include:• Intrathecal• Injection into cerebrospinal fluid around
spinal cord• Intraventricular• Injecting antibiotics or chemotherapy
agents into brain cavities (ventricles)
Routes of AdministrationRoutes of Administration
• Parenteral Other parenteral routes include:• Intravesicular• Injection into urinary bladder
• Intravitreal• Injection into vitreous body of the eye
Routes of AdministrationRoutes of Administration
• Topical Administered externally to the skin Absorbed into the mucous membrane,
preventing particles from being absorbed into the bloodstream
• Rectal Administered through the rectum for
local or systemic effects
Routes of AdministrationRoutes of Administration
• Vaginal Medications inserted into vagina for
absorption and distribution for local or systemic conditions
• Ophthalmic Solutions, ointments, suspensions, or
gels administered through the eye Treats conditions of the eye directly
Routes of AdministrationRoutes of Administration
• Otic Medications administered in the ear to
treat infections, inflammation, and severe wax buildup
Solutions and suspensions absorbed in the ear canal for immediate relief
SummarySummary
• Drug sources, nomenclature, common dosage forms, routes of administration
SummarySummary
• Important to: Dispense proper dosage form of
medication Dispense proper dosage amount,
especially for parenteral ROAs• Pharmacy technician must understand
drug names, the meaning and use of each dosage form and ROA.
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