Lecture 13: Intro To Pharmacy Practice Dispensing And Compounding Flashcards
What are some of the types of preparations for oral use
Capsules, powders, granules
SOLID dosage forms:
e.g, digoxin capsules for atrial fibrillation in children
Solutions, suspensions, emulsions, mixtures, linctuses, elixirs, oral drops
LIQUID dosage forms:
different viscosities, different solvents
e,g, choloral elixir paediatric (sedative),
liquid paraffin emulsion (lubricant laxative)
spironolactone suspension (diuretic)
What is Douglas pharmaceuticals?
Biggest pharmaceutical manufacturing company in NZ
Founder Sir Graeme Douglas started as community pharmacist in Auckland
In 60s/70s: imported or compounded pharmaceutical products not available in NZ
Started small manufacturing business in 70s due to high demand.
1990 moved to Henderson (current site)
Now exports pharmaceuticals all over the world
What are some preparations for external use?
Applications/collodions/liniments/lotions/paints:
LIQUID preparations for topical application
Base may be aqueous, oily or alcoholic
E.g. Calamine lotion BP for skin irritation
Turpentine liniment BP for muscle strain
Creams/ointments/pastes/gels SEMISOLIDS for topical application E.g. Zinc and coal tar ointment APF antipruritic for itching Aqueous cream BP emollient cream Dithranol paste BP for psoriasis
What are some preparations for miscellaneous use?
Ear drops/nasal drops
E,g, ephedrine nasal drops (nasal decongestant)
Inhalations/mouthwashes/gargles
E.g. Phenol gargle BP (antiseptic mouthwash)
Methanol and eucalyptus inhalation BP (nasal decongestant)
Suppositories/enemas/pessaries
Suppositories (SOLID) and enemas (LIQUID) for rectal administration;
pessaries for vaginal administration
E.g. Paracetamol suppositories (analgesia)
What does competence standard 6 cover?
Dispensing: the supply of prescription medicines and pharmacist only medicines including extemporaneously compounded products
All actions and responsibilities of the pharmacist from receipt and checking of a prescription or patient request, dispensing and labelling the product, through to counselling the patient about the use of the medicine
What is good dispensing practice?
Check that prescription is legal, completely, clinically appropriate etc
Follow up any queries with prescriber, check patient records
Assess safety and appropriateness of the medicine for that patient
Safe and disciplined dispensing process including checking procedures, products could be preformulated or compounded
Maintain legal dispensing records
Counsel patient appropriately
What does competence standard 7 cover?
Compounding : the preparation of pharmaceutical products in hospital and community pharmacies
Pharmacists prepares small quantities of extemporaneously compounded products such as cream suspensions NZ suppositories (I,e, small scale manufacture of medicines from bulk ingredients)
Standard 7 sometimes viewed as more specialised aspect of standard 6
Why is compounding needed.,
Traditionally a major component of pharmacy practice
From 1950s, shifted towards pre manufactured products from industry e.g. Tablets, capsule am inhalers, cream etc
1980s and 1990s: intro of Code of good manufacturing practice to pharmacy: stringent standards for compounding, now replaced by pharmacy service standards
Further decline in compounding especially in community pharmacy
Resurgence in recent years
What are some reasons for compounding?
Unavailability of dosage forms for selected patient groups e,g, child, elderly, or particular issues in NZ with PHARMAC restrictions
Unlicensed product in NZ
Hospitalised patients nil by mouth
Patients unable to take standard dose forms e,g, if vomiting, difficulty swallowing, short gut (following surgery)
Palliative care patients- may require administration of medicines n unconventional ways
IV nutrition patients
Patients may be allergic to some ingredients in commercial products e.g. Arachis (peanut) oil or colouring agents
Specialist veterinary products
Marketing (some patients like the idea of boutique brand of medicine)
Emergence n recent years of specialist compounding pharmacies
What are the procedures for compounding?
Items usually, but not always individually prescribed for a patient on a prescription from a medical practitioner
Usually manufactured according to an official or local formula
eMixt contains info about standardised formulations for NZ, paediatric oral liquids and other practical formulation issues
Strict protocols are employed (equipment, documentation, personnel etc)
Intended to be used within a strict period
What are skills required for compounding?
Reading and interpreting prescriptions
Using pharmaceutical reference sources
Finding formulae and performing pharmaceutical calculations
Following documentation procedures
Following standard operating procedures
Using generic skills like weighing, measuring etc
Using specific compounding skills like mixing diluting etc
What other skills are required for compounding?
Checking doses
Selection of containers
Labelling- standard and additional information
Storage and expiry
Medication counselling
General awareness of accuracy, organisation, hygiene, cleanliness, professionalism
What are some common reference sources for formulae?.
PharmInfo Tech
Pharmaceuticals heddle
Australian pharmaceutical formulary
Traditional reference sources - not used much now
What are some basic conversions used in pharmaceutical calculations?
1kg=1000g
1g=1000mg
1mg=1000μg
1L= 1000mL
What are some expressions of strength in pharmaceutical calculations?
Ratio of 1:10
= 1part in 10parts. E.g. 1g in 10g
E.g. If 1g of NaCl is in 10mL of solution this is expressed as a percentage strength 10%w/v
What are some tips for calculations?
Always approximate your answer before inputting in calculator
- should know what you roughly expect before tapping in actual figures
- calculations good for checking your answer is correct and getting exact amount
Always calculate twice to double check
Try working in reverse to see if you get same answer
What is professor Shaw’s famous saying?
A decimal point can kill your patient!
Why is documentation required in compounding?
Documentation is very important. Full documentation is required for all extemporaneously prepared products
Requires record o formula, batch#, calculations, methods, expiry dates, etc
Often use standard operating procedure for a specific product
What is dose?
The amount of medicine taken or given at ONE time
What is dosage?
The amount of medicine to be taken or given in a PERIOD of time
When might the number of doses need to be decidedly the prescriber or you, the pharmacist?
If the formula recommends an amount per day in divided doses
E.g.
Pholcodine linctus BP, 20-40mL daily in divided doses
You might suggest 5-10mL four times per day
What happens if the standard text gives ranges for particular condition at a particular age?
You are not expected to know all the specific details of dosing. But when working from a formula always check the dose range is appropriate for your patient, especially for children and elderly
How might you accommodate dosages for children or elderly patients?
Child- weigh them
Elderly: generally lessen dose due to renal/hepatic not functioning as well as younger patients
Why are storage and expiry dates important?
They are a legal requirement
(Every extemporaneously prepared product has an expiry date)
Unfortunately for many preparations, stability data and microbiological data is not known
Standard texts don’t always agree
PSNZ has some recommendations largely based on common sense
Why are preservatives used?
To prevent contamination and spoilage
Chloroform water used in many official formulae but here we swap it for something else as it may be a carcinogen at high amounts
Recommended not to be used for internal medicines.
Recommends compound hydroxybenzoate solution APF0.1% aka parabens used as alternative
Why kind of containers are used?
Variety of containers available depending on type of product
Internal liquid preparations: standard medicine bottle (glass, plastic or amber-for protection from sunlight )
For internal use: smoother external surface (non ribbed)
What are some standard techniques used ?
Generic skills of compounding are weighing and measuring
Accuracy and precision are fundamental to good practice
What are the two scales used to weigh solids?
Class B Bean balance
Traditionally used. Still used by many pharmacies.
It calibrates but may be hard to use if there is a breeze
Electronic top loading balance
Aka top pan balance
Digital readout and different levels of sensitivity
Many pharmacies switching to this type, but its expensive
How can liquids be measured?
Straight Measuring cylinder
Conical measuring cylinder
For range of volumes, glass stirring rod can be used to dissolve solids
Pipettes, syringe, dropper
To measure small volumes particularly for adding to a bulk solution or making up to volume
