Extemporaneous compounding Flashcards
What is extemporaneous compounding?
-manipulation of drugs and chemical ingredients via traditional compounding techniques to produce medications suitable for patients when no commercial forms are appropriate
What is off label or unlicensed use?
- the use of medicines outside its product license or approval
- this can be for the treatment of a different disease or the use of medicine by different population groups
What are the preferred dosage forms for infants 1month - 2 years old?
small volumes of liquids
e.g. syrups and solutions
What are the preferred dosage forms for children (aged 2-5 years)?
- liquids
- effervescent tablets
What are the preferred dosage forms for children 6-11 years ?
-solids like chewable tablets and orally disintegrating tablets
What are the preferred dosage forms for adolescents (12-18 years)
-solids, typical adult dosage forms like tablets and capsules
What are the reasons for compounding?
- required dosage form of a medicine does not exist/is not available
- allergy sensitivity to an inactive ingredient in manufactured products
- unavailability or discontinuation of a medicine
- requirement for different dose, concentration or route of administration
- novel therapies and specialist products used in hospitals and clinics
Is compounding accurate?
-medicines manufactured by Pharma company will be more of a reliable quality than that compounded in pharmacies due to strict quality control processes and equipment, but sometimes compounding is necessary so we must learn the ground level principles and adapt to the situation.
What are the risks assoc with extemporaneous compounding?
- formulation failure due to chemical and physical instability
- microbial contamination
- calculation errors
- patient acceptability issues
- health and safety risks
- therapeutic risks and clinical consequence
What are some drugs not available as liquids?
- acetazolamide
- amlodipine
- captopril
- allopurinol
- lamotrigine
- omeprazole
- rifampin
- topiramate
- azathioprine
- levodopa/carbidopa
- amiodarone
How is stability assessed?
- using various storage conditions
- chemical stability testing by HPLC
- physical stability testing for appearance, pH, viscosity, microbiology
What storage conditions should compounded products be tested at?
- fridge: 4 degrees C
- room temperature: 20 degreesC
- 40 degrees C/75% RH
What was the problem with ADHB phenobarbitone oral liquid ?
- contained phenobarbitone pure powder in a mixture of glycerol and water
- expired in 7 days if refrigerated
- had problems with stability, short date resulting in frequent compounding
- had an unacceptable taste leading to non compliance and treatment failure
What was the result of the phenobarbitone investigation?
- recommended optimal flavour for SP base was lemon 0.75% w/v
- HOS formulation exp date extended to 6 weeks
- found to be liquid SP-F stable for 4 weeks (refrigeration optional)
- better palatability and visocsity properties
What are the good sources of info to go for extemporaneous compounding?
- David Woods website
- Trissel’s stability of compounded formulations
- APF
- International journal of pharmaceutical compounding
- NZHPA CNO sig
What are the steps to preparing paediatric oral liquids?
- consider alternative drug
- consider alternative method e.g. tablet dispersion or oral admin of injection
- consult latest info databases and publications, prepare formulation according to published study and follow conditions as closely as possible. Modifications are only appropriate if there are no detrimental effects on stability
What stability information and patient info is require in the preparation of paediatric oral liquids?
- may be possible to adapt existing info from drug stability texts e.g. solubility, pH stability profile, or from the formulation details of the injection or oral liquid available elsewhere
- provide info to carers to ensure correct use including storage conditions, use of oral syringe, shaking before admin.
What are the suspending agents for oral liquid formulation?
- these are preformulated and flavoured suspending agents for insoluble drugs
- they can be used for bitter tasting drugs due to sweetening effect
- in NZ we have Ora-Blend, Oral Plus and Ora-sweet
What are the neonatal adverse reactions for oral or parenteral benzyl alcohol?
-neurotoxicity, metabolic acidosis
What are the neonatal adverse reactions for oral or parenteral ethanol?
-neurotoxicity
What are the neonatal ADRs for parenteral polyethylene glycol?
metabolic acidosis
What are the neonatal ADRs for parenteral Polysorbate 20 and polysorbate 80?
liver and kidney failure
What are the neonatal ADRs for oral and parenteral propylene glycol?
seizures, neurotoxicity, hypoeromolarity
What does Trissel’s stability of compounded formulations contain?
- properties (solubility, pH, pKa)
- general stability considerations
- stability reports of compounded products
- commercial availability
