Extemporaneous dispensing introduction Flashcards
When are small scale manufacture of medicines used (5)
- Products unavailable from the manufacturer
- Products requiring specific dose (elderly / children)
- Products requiring specific formulation
- Non-licensed products
- Veterinary products
What is the pharmacist’s responsibility for small-scale manufacture of medicines (5)
- Ensure formula & dose are safe
- Materials appropriate quality
- Adequately trained staff
- Record keeping
- Use of SOPs
What should the working environment be like for small-scale manufacture of medicines (6)
- Organisation
- Safe system of working
- Health & safety
- Cleanliness & hygiene of bench, equipment, instruments, dispensing container
- prevention of contamination of ingredients
- prevention of microbial contamination
What are the procedures for small-scale manufacture of medicines (6)
- Comprehensive records essential
- Kept for minimum of 2 years (ideally 5)
- Include formula, calculations, ingredients, quantities, sources, batch numbers, expiry dates
- All calculations, weights/volumes: 2 stage process of checks
- Hazardous substances: record special precautions
- Prescribed item: patient & prescription details, date of dispensing
what are the weighing equipment for small-scale manufacturing of medicines (2)
- Non-automatic and automatic weighing equipment.
- Non-automated dispensing balances include mechanical beam and electronic top-pan balances.
What are the three types of balances traditionally used in dispensing (3)
- class A (50mg to 1g)
- class B (100mg to 50g)
- class C (1g to 2kg).
What are the rules for use of weighing equipment (8)
- Place on level surface – Level indicator device
- Zero before use
- Site in draught-free area
- Balance pan clean
- When using top-pan balance, use weighing boat or piece of paper and auto-zero to cancel weigh
- Record weight of boat / paper
- Never split quantities – will increase inaccuracy
- Caution, scales have a minimum weighable quantity
How are conical measures used (5)
- Level of liquid read to bottom of meniscus at eye level
- Measure vertical when reading
- Thoroughly drained
- Use smallest measure
- Viscous liquid must be measured by difference or rinsed
how are small volumes measured (2)
- 5mL to 0.1mL
- less than 0.1mL requires dilution
What are the heat sources used in extemporaneous dispensing (3)
- Bunsen burner, Yellow flame – carbon
(for safety/visibility – NOT for heating), Blue flame – hottest - Water bath - For flammable substances e.g. melting ointment bases, preparing suppositories
- Electric hot plates - Traditionally used when stiff ointments and pastes needed to be prepared extemporaneously as an aid to softening the base.
what are used for mixing and grinding in extemporaneous dispensing (3)
- Mortar (bowl) + Pestle (pounding device)
- Glass - Small, used for mixing, Smooth surface, not suitable for size reduction
- Porcelain - Rough surface ideal for size reduction and mixing powders & liquids, making emulsions
What is the manipulative technique of mixing
To ensure that even distribution of all the ingredients has occurred.
What is the manipulative technique of mixing of liquids (2)
- Simple stirring or shaking
- the degree depends on the viscosity of liquids
What is the manipulative technique of mixing solids with liquids (2)
- stirring rod (solution), pestle and mortar (suspension).
- Consider size reduction to speed up dissolution process or enhance the distribution of solid through out the liquid.
What is the manipulative technique of mixing solids with solids (2)
- mortar and pestle
- “doubling up” procedure.
What is the manipulative technique of mixing semi-solids (2)
- rubbing them on an ointment slab using a spatula (may need doubling up).
- The fusion method using a porcelain evaporating basin.
What are tared containers (4)
- container marked with a predefined fill level
- ensures accurate volume
- achieved by marker pen or paper label
- “Accurate reading of the meniscus is essential when preparing the tare volume”
What is important when considering ingredients (4)
- Quality - BP standard is the normal requirement, although food grade is acceptable in certain circumstances
- Selection - Care with names / synonyms
(e.g Lanolin / hydrous wool fat, Magnesium sulphate / Manganese sulphate) - Forms - Hydrated / anhydrous (e.g. Glucose, anhydrous C6H12O6, Glucose monohydrate C6H12O6,H2O)
- Chloroform - Chloroform, chloroform water, chloroform water double strength, chloroform water concentrated
What is the use of light magnesium carbonate
Because of lightness and diffusible properties, it is used in suspensions
What is the use of heavy magnesium carbonate
Normally used in bulk or individual powders
What is the use of light kaolin
Used in suspensions
What is the use of heavy kaolin
Used in the preparation of kaolin poultice
What is the use of precipitated sulphur (2)
- Has a smaller particle side then sublimed sulphur
- Is preferred in preparations for external use (suspensions, creams & ointments )
What is the use of sublimed sulphur
Slightly gritty powder which does not produce such elegant preparation as precipitated sulphur
What is the use of yellow soft paraffin
Used as an ointment base
What is the use of white soft paraffin (2)
- Bleached yellow soft paraffin
- normally used when the other ingredients are not strongly coloured
What is the synonym for the substance wool fat
Anhydrous lanolin
What is the synonym for the substance hydrous wool fat
Lanolin
What is the synonym for the substance hard paraffin
Paraffin wax
What is the synonym for the substance compound benzoic acid ointment
Whitfield’s ointment
What is the synonym for the substance macrogol 2000
Polythylene glycol 2000 (PED 2000)
What is the synonym for the substance theobroma oil
Cocoa butter
What Laboratory conduct must be maintained (21)
- Allocated bench places
- Lab coat essential
- Tie back long hair
- No long/false nails
- Safety glasses not required
- Responsible for cleanliness of workplace and equipment used
- Clean up spillages immediately
- Broken glass in glass bin
- Hand in air to summon staff
- Each bench - own equipment / materials
- Do not use anything from other benches
- Equipment / dispensing containers placed at end of bench
- Measures, spatulas, tiles, bottles, jars etc.
- May have to share certain items e.g. bunsens, balances
- Ingredients by sink
- Do NOT transfer ingredients to separate container and take to work place
- Use quantity required and NO more
- DO NOT contaminate ingredients
- Make sure all equipment is CLEAN
- Retain ingredient until checked
- Return to end of bench after use
What is the laboratory conduct for using balances (3)
- Keep clean at all time
- Take care when measuring
- Clean spillage immediately
What is the laboratory conduct for using electronic top-ban balances (3)
- Use for quantities no smaller than 100mg
- Require weighing boat
- Use tare facility wisely – may need to record weights!
