Design Of Medicines Flashcards
(30 cards)
formulation converts…
drug into medicine to achieve bioavailability, stability + efficacy
formulation includes…
methods of manufacture, ingredients, excipients, appearance, colour + taste
when should small scale products (extemporaneous dispensing/compounding) be used? and why?
when medicinal prod not available
because they cannot be well controlled
what are extemporaneous preparations?
medicines prepared depending on request (legal prescription) from prescriber
what are the factors that affect safety of medicine?
- correct drug
- correct dose
- correct method of delivery (correct label)
what are the positive and negative therapeutic actions of a drug?
positive - medicinal purpose
negative - side effects
what is the shelf life of a pharmaceutical product?
period during which the product = expected to maintain its physical + chemical properties unchanged
shelf-lives for extemporaneous preparations do not exceed….
1 month
what are the different types of degradation?
- chemical
- physical
- microbiological
what are suspensions?
preparations that contain fine drug particles distributed uniformly throughout a vehicle
the formulation of a suspension having optimal physical stability depends on …
whether particles = flocculated / remain deflocculated
describe the approaches to suspension formulations?
- dispersed phase (particles)
- addition of wetting agent + dispersion medium
- uniform dispersion of deflocculated particles (extemporaneous dispensing - stability only 2 weeks)
- incorporation of structured vehicle (deflocculation)
OR
addition of flocculating agent
if the powder is not wetted when the medium is added, what will happen and how can you overcome this?
particles will clump + float on top of vehicle —> uneven suspension
wetting agent should be added
during extemporaneous compounding of suspensions, what does the pharmacist do?
- adds contents to mortar
- crushes tablets using mortar with pestle
- selective vehicle added slowly to create paste
- then diluted to desired vol
liquid forms have faster…
decomposition compared to solid forms
exposure of product to light can have what effect?
deleterious effects on product integrity
what can be added to protect against bacterial contamination?
preservative
what are the details that must appear on the label of dispensed medicines?
- name of preparation
- quantity
- instructions for patient
- patients name
- date of dispensing
- name + address of pharmacy
- warning/ advisory labels (shake bottle)
- batch/prod number
- expiry date
- ‘keep out of reach of children’
what are powders?
dry mixtures of finely divided medicinal + non-medicinal agents intended for internal/external use
what are the advantages of powders?
- solid prep more stable than liquid formulations
- powders + granules = convenient forms as drugs with large doses dispensed easily
- have faster dissolution rates than tablets/capsules
- easy for compounding solids
what are the disadvantages of powders?
- less convenient for patients to carry
- problematic in masking unpleasant taste
- not suitable for administrating potent drugs
- not suitable for drugs that = inactivated in stomach
- not suitable for hygroscopic drugs
how can you reduce particle size?
grind with mortar and pestle (trituration)
what is levigation?
when non-solvent is added to the solid to form paste
rubbing the paste in a mortar with pestle
when mixing 2/more powders, what method is applied?
geometric dilution
to obtain uniform distribution
