Lecture 13: Intro To Pharmacy Practice Dispensing And Compounding

Question 0

What are some of the types of preparations for oral use

Answer 0

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)

Question 1

What is Douglas pharmaceuticals?

Answer 1

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

Question 2

What are some preparations for external use?

Answer 2

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

Question 3

What are some preparations for miscellaneous use?

Answer 3

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)

Question 4

What does competence standard 6 cover?

Answer 4

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

Question 5

What is good dispensing practice?

Answer 5

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

Question 6

What does competence standard 7 cover?

Answer 6

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

Question 7

Why is compounding needed.,

Answer 7

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

Question 8

What are some reasons for compounding?

Answer 8

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

Question 9

What are the procedures for compounding?

Answer 9

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

Question 10

What are skills required for compounding?

Answer 10

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

Question 11

What other skills are required for compounding?

Answer 11

Checking doses
Selection of containers
Labelling- standard and additional information
Storage and expiry
Medication counselling
General awareness of accuracy, organisation, hygiene, cleanliness, professionalism

Question 12

What are some common reference sources for formulae?.

Answer 12

PharmInfo Tech

Pharmaceuticals heddle

Australian pharmaceutical formulary

Traditional reference sources - not used much now

Question 13

What are some basic conversions used in pharmaceutical calculations?

Answer 13

1kg=1000g
1g=1000mg
1mg=1000μg
1L= 1000mL

Question 14

What are some expressions of strength in pharmaceutical calculations?

Answer 14

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

Question 15

What are some tips for calculations?

Answer 15

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

Question 16

What is professor Shaw’s famous saying?

Answer 16

A decimal point can kill your patient!

Question 17

Why is documentation required in compounding?

Answer 17

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

Question 18

What is dose?

Answer 18

The amount of medicine taken or given at ONE time

Question 19

What is dosage?

Answer 19

The amount of medicine to be taken or given in a PERIOD of time

Question 20

When might the number of doses need to be decidedly the prescriber or you, the pharmacist?

Answer 20

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

Question 21

What happens if the standard text gives ranges for particular condition at a particular age?

Answer 21

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

Question 22

How might you accommodate dosages for children or elderly patients?

Answer 22

Child- weigh them

Elderly: generally lessen dose due to renal/hepatic not functioning as well as younger patients

Question 23

Why are storage and expiry dates important?

Answer 23

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

Question 24

Why are preservatives used?

Answer 24

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

Question 25

Why kind of containers are used?

Answer 25

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)

Question 26

What are some standard techniques used ?

Answer 26

Generic skills of compounding are weighing and measuring

Accuracy and precision are fundamental to good practice

Question 27

What are the two scales used to weigh solids?

Answer 27

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

Question 28

How can liquids be measured?

Answer 28

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