dosage forms Flashcards
What are the different delivery routes?
*Oral
*Buccal
*Sublingual
*Nasal
*Ocular
*Intra-arterial
*Intra-venous
*Intra-muscular
*Intra-dermal
*Topical
*Transdermal
*Pulmonary
*Aural
*Rectal
What is systematic drug delivery? + most common type of dossage form
– Where the drug reaches the site of action through the systemic
(cardiovascular) circulation
– Oral dosage forms are the most common type of systemic dosage
form
What is local drug delivery?
– Drug is delivered directly to the site of action via the dosage form
(or the action of the dosage form)
– Topical drug delivery, i.e. to the skin, using creams/ ointments/ gels
is a good example
What are the three types of oral dosage forms?
*tablets
*capsules
*powders and granules
How do tablets work?
Tablet must disintegrate in the gastro-intestinal
(GI) tract and the drug then enter solution
How do capsules work?
Capsule shell quickly dissolves in the stomach and
releases the drug
– Liquids / emulsions / pastes may be incorporated
in 1-piece soft gelatin capsules
What are powders and granules typically mixed with?
mixed with water in bulks or single dosages
What are the three types of oral dosage forms?
*solutions
*suspensions
*emulsions
How does drug dispersion work in solution?
– Drug and other excipients are completely dissolved, i.e. as
a molecular dispersion, in a liquid (solvent)
– Faster acting than an equivalent tablet formulation –
disintegration and dissolution steps are absent
How does drug dispersion work in suspensions?
– Drug and/or other excipients remain as solid particles
dispersed in the “vehicle”
– Usually employ a suspending (thickening) agent to keep
the particles dispersed
How does drug dispersion work in emulsions?
– Dispersions of (at least) two immiscible or
partially miscible liquids
– Medicinal oils, supplements,
lipophilic drugs
What are the 5 types of rectal and vaginal dosage forms?
- suppositories
*enemas
*foams
*pessaries
*vaginal creams and gels
How do suppositories work?
– Drug is incorporated into a water-soluble/
dispersible base or a base which melts at
body temperature
– Once inserted the drug will be released to
exert a local or (sometimes) systemic effect
What are enemas?
– Liquid preparations formulated for rectal delivery
What are foams?
– Two-phase system administered from a pressurised container
– Drug dissolved in the liquid phase
What are the five topical and transdermal dosage forms?
- creams
- ointments
- gels
*Pastes / sprays / lotions / foams
*transdermal therapeutic systems (patches)
What is a cream?
Semi-solid emulsion preparations usually
applied topically to the skin, but
formulated for other delivery routes
What is an ointment?
– Single-phase semi-solid base in which a drug can be dispersed
– Have excellent emollient properties
What is a gel?
– Single-phase semi-solid preparations, usually aqueous in nature
How are parenteral dosage forms administered?
Drug (or source of calories/ nutrients/ hydration) administered
via a hollow metal needle
What are the two types of parenteral dosage forms?
- injections
- infusions
What is an injection and common routes?
– Sterile liquid preparation drawn up and injected from
a vial, ampoule or pre-filled syringe
– Typically IV, IM or SC, but many other routes
– Can utilise a syringe driver (or pump)
Why do we utilise infusions?
can be used to deliver larger volumes IV and can be in solution or emulsion form
What are the 3 types of pulmonary drug delivery systems?
- Inhaler
*nebuliser - electronic cigarette
How are nebulisers useful?
– Convert liquids to aerosols (dispersion of a liquid or a solid in a gas)
– Useful for delivering larger doses of drug
What are typical ocular dosage forms?
Formulations: solutions,
suspensions, gels,
emulsions, injections
What should be considered when giving ocular drugs?
Consider: osmolarity,
pH, surface tension
What are the typical sublingual/ buccal dosage forms?
Small porous tablets enabling
faster disintegration & drug
release
* Sprays (sublingual)
* Orodispersible/ “melt”
tablets
What are the typical nasal dosage forms?
Formulations: solutions,
suspensions, emulsions
(dropper bottles, sprays); gels,
creams, ointments; powders
(pMDIs)
What should be considered when delivering nasal drugs?
Consider: irritancy, residence
time
* Systemic and delivery to the
brain are possibilities
What are the typical aural dosage forms? what are the exceptions?
Topical drug delivery:
drops, gels, foams.
* Middle/ inner ear: often
require other approaches,
e.g. implants/ injections
What are some examples of advanced dosage forms/ technologies?
- Needle-free technology, e.g. jet injection systems and
microneedles - Implantable delivery systems
- Nanotechnology
- Cell-based therapies
