D. Pharmaceutics Flashcards
What are ‘specials’?
Medicines made for
individual patients with special
needs that can not be met by
licensed medicines
What features are present on the ‘main label’ in ‘specials manufacturing’?
- Dose, frequency and other instructions
- Storage instructions
- Discard unused contents after….
(the expiry date) - Date of manufacture
- Batch number
- Patient name
What features are present on a ‘ancillary label’?
- BNF WARNINGS
- KOOSAROC - for ALL meds
- Shake the bottle - for ALL liquid meds
- Use this medicine only on your skin - for ALL Skin meds
- Not to be taken - On non-skin products that are not to be
swallowed e.g. eye drops, ear drops
How do you decide on an expiry date for a special?
- The instabilities of the ingredients
- The stability of the medicine itself
- The protection provided by the packaging
- Any risks of microbial contamination during use e.g. eye drops or creams in a jar
Why store in a cool place?
To protect against instabilities like heat, microbiological
growth, volatile
ALL powder meds must be stored in a cool place
Why store in a dark place?
To protect against instabilities like oxidation and light.
Why store in a dry place?
To protect against instabilities like moisture.
A medicine containing water should not be stored in a
Why store in a tightly sealed container?
To protect against instabilities like moisture and air
What are some routes of administration for bulk powders?
- Dusting powders
- Nasal spray
- Dry powders inhaler
How are oral bulk powders packaged?
In a jar or vial
How are oral bulk powders taken?
- Either spoonfuls of powder dispersed in water, milk, …or
sprinkled onto food sprinkled on food - reconstituted in water before dispensing- useful when the drug is unstable in water
What are the advantages of sachets over bulk containers?
- More accurate dosing
- better protection against moisture,
- more convenient
What are the advantages of oral bulk and wrapped powders over tablets or liquids?
- Patients who have difficulties swallowing tablets or capsules
- more stable that liquid meds
- can give large doses orally
- fast dissolution and action
What are the disadvantages of powders?
- They are hygroscopic so they can cake
- can seperate- due to different size particles and vibration from transport, mixing and pouring
- can have poor flow, which is hard to pack
Features of a hard capsules
- Hard polymer shell soluble in water
(gelatin or HPMC) - Two parts: body and cap
What are hard capsules filled with?
- Powder mixture
- Small tablets
- Granules
- Combinations
(ex: powder + tablet)
What are the advantages of hard capsules?
*easy to swallow
*easier to manufacture than tablets
*different sizes
*Some can be opened
*shell protects the powder
Shell can sometimes mask taste
*shell can be coloured better identifying or delayed release
What are the features of tablets
- Coating (optional)
- drug + excipientsb in the core (matrix)
- print (name or other writting)
- break line
What are the advantages of tablets?
- small, portable, convenient
- very stable (no water, coating so lower risk of hydrolysis)
- shape and colour give a distinct market identity
How do tablets release drugs in the body?
- disintegrants/ disintegrating agents absorbs water and swells tablet
- tablets breaks into small pieces and dissolve so that the drug is in solution
- the drug crosses the gut wall by absorption
- drug in bloodstream
- distributed in the body
- therapeutic effect
How do capsules release drugs in the body?
- The polyer shell of the capsule dissolves in the GI fluid
- powder released and drug dissolves
- drug crosses the gut wall by absorption
- drug in bloodstream
- distributed around the body
- therapeutic effect
What are the different types of tablets?
- Dispersible/ effervescent
- Immediate release
- Extended release
What are the features of dispersible tablets?
- Dissolve in water / or on tongue
- fast acting
- effervecsent mixture or thin porous tablets
Features of Immediate release tablets
- Disintegrates and releases drug in stomach
- fast acting
How do delayed release tablets work?
- remain intact in the stomach
- disintegrates in the small intestine
- enteric coating is insoluble in acid but soluble at neutral pH (in intestine)
- coating is sometimes called enteric coating
What is a delayed release tablet?
A tablet that is resistant to stomach acid
When are delayed release tablets used ?
- If the drug degrades in the stomach
- irritates the stomach
- once a day dose is required
- fast drug release causes side effects
How are extended release drugs designed?
- A insoluble porous coating
OR - a matrix that erodes slowly
What are the different types of liquid medicines?
- Solutions
- Suspensions
- Emulsions
What are solutions?
- Soluble liquid + soluble liquid
OR - soluble solid + soluble liquid
What is a suspension?
Insoluble solid + liquid
What is an emulsion?
Insolule liquid + liqiud
What are the types excipients in liquid medicines?
- Vehicles
- stabilisers-preservs,antiox,buffers
*Appealers-flavours,sweetners,colours - specifc to types-thickners,solubility enhancers, emulsifying agents
What is a vehicle?
The main liquid ingredient
What are common vehicles in liquid meds? And function
- water
- thick sweet liquids-more palatable, pourability
glycerol,syrup,sorbitol solution
- other liquids e.g. alcohol, ether, propylene glycol
Preservatives are to prevent what in liquid meds?
- growth of microbes
- food poisoning
- contamination
- mircrobes degrading the meds
What antioxidants do in liquid meds?
- more easily oxidised so prevents oxidation of drug favouring the unionised form
- terminates oxidation/free rad reactions
What are some examples of water soluble antioxidants?
- Ascorbic acid (vit c)
- Sulphites
- SO2
What are chelating agents used for and give an example
Reduce the ability of heavy metal ions from catalysing oxidation reactions
e.g. EDTA
Why is it important to control the pH of the medicine?
- specific solubility requirements
- to prevent dregradation
- effectivness of excipients
- safety
- taste
What are some sweetners and characteristics of them.
- Sugars-causes tooth decay, preservative if undiluted
- Glycerol - demulcent (prevent irr)
- Sugar alcohols- not calorie free, can causes diarrhoea, cramps, bloating
- Artificial sweetners - possibly carcinogenic
What are flavours use for in liquid meds?
Mask taste
What do solubility emhancers do in liquids meds?
Help the drug and excipients to dissolve
E.g. micelles, cosolvents
What are two physical stability problems with suspensions?
- seperation- particles fall to the bottom due to gravity
- caking- particles bound together
Risks of ununiform suspensions
- low drug content at the top
ineffective/ sub-therapeutic - High drug content at the bottom
Overdose