Dosage Forms and Routes of Administration Flashcards
dosage form
- the way a drug is identified in its physical form
- comprised of active and inactive ingredients
Defining Dosage Forms
- Physical appearance of drug product
- Physical form of drug product prior to dispensing
- The way a product is administered
- Dosage frequency
- How pharmacists and other health professionals might recognize and handle the product
Active Ingredients
drugs
inactive ingredients
excipients
excipients
provide the performance characteristics of the dosage form
- Can also include:
- diluents
- binders
- granulating agents
- glidants
- lubricants
- disintegrants
- sweeteners
- flavors
- pigments
- polymer coating
- Tablets must be strong enough to survive manufacturing, packaging and handling. excipients are important to this requirement
Primary Routes of Administration
- Oral (Enteral)
- Inhalation
- Parenteral
- Topical
- Suppository
Oral Route
- drug administration that involves taking medication by mouth
- most convient route for patients
Pills
- 1st solid oral-dosage form
- many still refer to tablets and capsules as pills
- date back to 1500 bc
- 500 bc earliest known trademark on pills with special indentations similar to today’s embossing
- early pill excipients were:
- honey
- bread dough
- grease
pilula
early name for pill
Tablets
- Most common form of solid oral-dosages
- standard compressed
- controlled release
- chewable
- orally disintegrating
- coated
tablete
- Old French word from which the word tablet is derived
- means “little slab”
William Brockedon
- 1844 in England invented compressed tablets
- (prior to this, they were rolled into long snakes or tubes and cut into “little slabs” = tablets)
- compressed manufacturing is now the most economical way to produce pharmaceuticals
High-Speed Tableting Machines
- can produce up to 1 million tablets per hour
- tablet manufacturing bacame high-speed following WWII when bullet manufacturing methods were modified to create tablets
diluents
a diluting substance
binders
a substance that causes the components of a mixture to cohere
granulating agents
a binding agent added to form the fine particles together into granules
glidants
flow aids used to maintain efficient movement of bulk powders from hoppers into the tableting press
lubricants
used to ensure the tablet is easily ejected from the compression mold
polymer coating
makes the tablet more resilient, extends shelf life, improves appearance while making a tablet easier to swallow, and controling how slowly or quickly the active ingredient is released
- are necessary for medications with an unpleasant taste
- must not stick together during the coating process
- must follow the fine contours of embossed characters or logos on the tablet
- must permit tablets to be permeable enough to eventually disintegrate in the GI tract
Tablet Shapes
- Round, Oval, and Capsule
- most common shapes
- Can be made in virtually any shape, however the 3 most common are easiest for patients to swallow and the more uncommon shapes are prone to chipping and breakage during manufacturing, shipping and handling
Tablet Administration
- orally
- sublingually
- buccally
- ODT
- rectally
- intravaginally
sublingually
under the tongue
buccaly
between the cheek and gum
rectally
anus administration
intravaginally
vagina administration
ODT
orally disintegrating tablets
- designed to break up when the touch saliva - used for the population of patients who have trouble swallowing
caplet
a tablet that is smooth, coated, and oval-shaped in the general shape of a capsule
Capsule
- 2nd most common oral-dosage form
- comprised of a gelatin “shell” and the medicinal “filling”
- may be hard or soft shelled
- may be powder, liquid or pellet filled
- may be coated
- mayb be banded (against tampering)
capsula
Latin word from which the word capsule is derived
- means “small box or container”
softgels
- were the first capsules
- invented in 1834 by a French pharmacist
- invented to mask the unpleasant taste and odor of many medicinal substances
- today they may be referred to as soft-shelled capsules
- and ar primarily used for oils and for active ingredients that are dissolvedor suspended in oils (poorly soluble)
- filling process ensures each softgell has the same amount and concentration of medication
- prevents operators from being exposed to drug dust, making them well suited for potent medications
James Murdock
- patented the 2-piece gelatin capsule in 1847, in London
hard-shelled capsules
- made using gelatin and contain dry, powdered ingredients, or miniature pellets
- composed of 2 halves:
- body
- cap
pellets
a way of controlled release with capsules
body
lower diameter shell of the capsule that is filled
cap
higher-diameter shell of the capsule that seals the body
capsule size
- variety of sizes
- 000 = largest
- 5 = smallest
gelatin
- as related to capsules:
- made mainly from animal protein
- similar to Jell-O gelatin
Modern High-Speed Capsule Machine
can produce up to 200,000 capsules an hour
Oral Liquids
- 3rd most common oral-dosage form
- mostly used for pediatric application
- oldest dosage system for medications
- history includes ancient elixirs and potions
Oral Liquid Forms
- solutions
- emulsions
- suspensions
- come either finished or in a granular or powder form that must be prepared just before use
- may be clear, colored, or cloudy
solution
a homogeneous, molecular mixture of two or more substances
homogeneous
as relates to medication forms, mixed together until the substances are mixed equally; one part of the solution is the same as any other part of the solution should it be divided (into doses, for example).
emulsions
- a dispersion of two insoluble liquids (phases)
- may settle upon standing with the phases distributed into distinct bands
- once shaken, the solution will become homogenous for a time.
suspensions
- a dispersion of solid particles in a liquid - usually water
- will settle upon standing
- homogeneous when shaken
multi-dose
a preparation of liquid medications where a prepared bottle of medicine is intended to be measured out into smaller, equal, sizes for administration
single-dose
a liquid medicine preparation where the entire mixture is intended for a one-dose administration
syrups
specialy liquid preparations that contain a high proportion of sucrose and are usually very sweet, making them well suited for masking unpleasant tastes and help children tolerate medications
- syrups have antimicrobial preservatives added since microorganisms grow well in sugar media
elixirs
have traditionally been ethanol-containing solutions
ethanol has been used to dissolve a drug substance with poor water solubility
reconstitutions
adding water to a dry drug substance
- many drugs lack water stability and have poor shelf life as a liquid preparation
- dry powders – such as antibiotics – will remain stable for years and can be reconstituted
- once reconstituted it becomes a suspension with exp. date of 14 days
microemulsions & nanoemulsions
newer forms of emulsion that disperses the insoluble phase into tiny droplets that are suspended in the continuous phase.
- the droplet size averages from micrometers to nanometers in diameter
- are clear, and may resemble a solution
- unlike other emulsions, these will not settle and do not require shaking
“Shake Well Before Use”
required labeling for both suspensions and emulsions
Inhalation
- very old method of medication administration
- primarily used to provide local relief of pulmonary symptoms associated with asthma and COPD
nasal inhaler
primarily used to treat hay fever and other allergies
aerosol therapy
becme the mainstay of respiratory care during the 20th century
aerosls
sprays of small droplets or particles suspended in a gas
Inhaler Classes
3 Major Classes:
- dry powder (DPI = dry powder inhaler)
- nebulizer
- metered dose
DPI
dry powder inhaler
Aerohaler
1950’s was early version of DPI that delivered PCN to treat respiratory infections
nebulizer
- dates back to ancient Greece for psychotropic drugs
- smoked leaves of the Datura ferox plant used to treat asthma in early 1800’s
- humidifier’s debuted in U.S. in 1949
- improvements continue
MDI
metered dose inhaler
- first approved for clinical use in 1956
- still widely used today
Inhaled Corticosteroids
- also referred to as topical corticosteroids or glucocorticosteriods
- anti-inflammatory medications that have been used successfully to treat asthma for over 50 years
bronchodilators
nonsteriod medications that open up airways by relaxing the small muscles that tighten the airways
rapid-acting bronchodilators
rescue inhaler or quick-relief inhalers
aerosol clouds
contain particles that are neither too small (risking exhalation) nor too large (tend to deposit primarily in the throat and upper airways)
pressurized MDI
- propels medication more deeply into the lungs than a regular inhaler
- guards against medications being deposited mainly in the throat, mouth and upper airways as is a common problem with regular inhalers and when patients inhale too forcefully with administration
spacer
- a divice that may be prescribed if the patient has trouble coordinating the medication delivery of an MDI with the inspiratory process
- spacer may also make the medication droplets smaller which enables them to be more easily drawn into the lower airways where they are needed
- some MDI’s have built in spacers
- some MDI’s are automated to release medication with the patitients inspiration through the inhaler
Inhalation Benefits
Many manufacturers are working on ways to deliver therapeutic agents by inhalation due to the fact that small molecules deposited in the lungs are very rapidly absorbed systemically due to these factors:
- huge surface area of the lungs
- highly dispersed nature of aerosols
- hundreds of millions of particles per dose
- good epithelial permeability
rapid absorption causes medication to be fast-acting
Parenteral Administration
medications administered directly into body tissues rather than through the alimentary canal
- SQ
- IM
- IV
alimentary canal
digestive system that extends from the mouth to the anus
para enteron
Greek words from which paraenteral is derived. Para meaning “beside” and enteron meaning “the intestine”
SC
- subcutaneous
- under the skin
IM
- intramuscular
- into the muscle
IV
- intravenous
- into the vein
Sir Christopher Wren
- 1st recorded injection of medicine into animals
- 1657
Dr. Alexander Wood
- 1855, performed the first SQ injection using hypodermic needle
Baxter
produced the first commercially prepared prepared intravenous solution in 1931
intravenous solutions became a mainstay of hospital care by 1950’s
nosocomial
hospital-acquired infections
parenteral advantages
Over other administration routes include:
- it can be used with drugs that are poorly absorbed or ineffective when given orally
- provides immediate onset of action
- can be used for slow or delayed drug action
- assures that a patient has received their dose of medication
parenteral disadvantages
over other drug administration routes are:
- costly and painful
- can be difficult to reverse
- requires aseptic technique
- requires special devices, such as infusion pumps
Special Injection Routes
Used by physicians only:
- intra-arterial = into an artery
- intraperitoneal = into organ cavity
- intracardiac = into the heart
- intrathecal = into spinal canal
deposition site
spot in which medication is injected or deposited
syrinx
Greek word from which we get syringe, means “tube”
barrel
of the syringe is a tube that is open at one end and tapers to a hollow tip at the other end
plunger
of a syringe is a tightly fitting rod that seals medication in the barrel and pushes it out the barrel tip as the blunger slides forward
tip
of a syringe is where the needle attaches to the syringe barrel
graduation lines
on the sides of the barrel show the volume of syringe solutions in mL’s or fractions of mL’s
Luer-Lok
common type of syringe tip that incorporates a twist-on coupler that locks the needle onto the barrel and creates a leak-free connection
Slip-Tips
a common syringe tip that makes needle installation quick and simple. The needle is held on the syringe by friction and is reasonably secure. The needle may come off if not attached correctly or if a lot of pressure used
Eccentric Tips
are used when a needle must be nearly parallel with the skin. The tip of the syringe is nearly in line with the outer edge of the barrel. enabling the barrel to be in close proximity with the skin. Good for injections into a surface vein.
Syringe sizes
- range from 1 - 60 mL’s
- as a rule, syringes should be selected that are the next size up from the volume to be measured
- syringes should not be filled to capacity to lessen the chance of the plunger becoming dislodged from the barrel
hub
of a needle is at the end of the needle and forms the adaptor that connects the needle to the syringe
shaft
of a needle is the length of metal that ends in the bevel
bevel
the sharp, pointed end of a needle
hollow bore
- lumen
- hollow space inside the needle shaft
Needle size
Designated by length and gauge
needle length
measured in inches from where the hub joins the shaft to the tip of the bevel
- range from 3/8 inch to 3 1/2 inches
- some specialty needles are even longer
needle gauge
refers to the size of the lumen
- range from 30G (smallest) to 13G (largest)
- G = gauge
needle size factors
- type and viscosity of solution
- nature of the rubber closure on the vial
coring
occurs when a needle punctures or tears a part of the rubber closure on the vial and the piece falls into the medication causing = particulate material contamination
filter needle
- depth needle
- has a small built-in filter between shaft and hub to remove any particulate matter
- commonly used with ampules
vented needle
allows the simultaneous addition of fluid and the vented building up of pressure from constituting a powdered medication
transfer needle
has a bevel at each end and is used when transferring the entire contents of one vial into another vial
parenteral solutions
come packaged as LVP solutions and SVP solutions
LVP
large-volume parenteral
- typically bags or bottles containing larger volumes (greater than 100 mL’s)
SVP
small-volume parenteral
- come in a unit dose container of 100 mL’s or less in a small plastic bag (minibag), ampules, vials, cartridges, and prefilled syringes
liquid parenteral drugs
are provided in prefilled syringes, heat-sealed ampules, or rubber sealed vials
powdered parenteral drugs
are provided in vials and they must be constituted before addition to any solution
constituted
dissolved in a suitable liquid
Topical Medications
drug applied to body surfaces
- date to 3000 bc in Ancient Egypt
topos
Greek word from which topical is derived, means “place” or “location”
topoi = Greek pleural form
Topical Applications
- Epicutaneous
- Ophthalmics
- Otics
- Dental
Epicutaneous
applied directly to the skin
ophthalmics
(eye drops) applied to the conjunctiva
factoid: eye drop solutions MAY be used in the ear
Otics
(ear drops) placed in the ear canal
factoid: ear drops MAY NOT be used in the eye because the eye is a sterile field and the ear is not.
local effect
medication affects only the area to which it’s applied
systemic effect
when medication affects the entire body system
base
as relates to medications: is the medium for the drug
the correct base is critical to patient treatment and should never be switched one for another.
topical base
usually wax or oil
potency
strength
Topical Solutions
- are of low viscosity
- often use water or alcohol as a base
Lotions
- thicker than solutions
- emollient - moisturizing in nature more than solution
- usually an oil and water mixture that contains less alcohol than a solution
cream
- an emulsion nof oil and water in approx. equal proportions
- penetrates the stratum corneum
- thicker than lotion and maintains shape when removed from the container
- has moderate moisturising qualities
stratum corneum
outer layer of the skin wall
ointments
- homogeneous, viscous, semi-solid
- generally 80% oil and 20% water
- very moisturizing
- unpopular due to greasy/oily application
prophylactic
disease prevention
Gels
- thicker than solution
- often are a semisolid emulsion in an alcohol base
- some will melt at body temp
Transdermal Patches
- medicated adhesive applications that time-release small amounts of medication into the blood stream through the membrane of the skin
Suppository
- rectum
- vagina
- urethra
- deliver systemic and local medications
