E-DRUG: RFI: Formulas for compounding of Essential drugs? (2)
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Dear E-druggers
Re: Formulas for Compounding of Essential Drugs
In response to Peter's query, I hope the following may be helpful:
A working definition of extemporaneous dispensing or compounding is the
mixing together of the ingredients of a prescription or drug formula and
generally refers to a manual process performed for individual orders by
a dispenser or pharmacist (taken from p181 of Managing Drug Supply 2nd
edition, Kumarian Press 1997).
It may also be described as the small-scale manufacture of medicines from basic ingredients.
According to the Royal Pharmaceutical Society of Great Britain
publication Professional Standards and Guidance Documents (Aug 2007)
section on Extemporaneous Preparation or Compounding, a product should
only be extemporaneously prepared when there is no product with a
marketing authorisation available and where it can be prepared in
compliance with accepted standards.
Other requirements include that:
- products are prepared accurately and be suitable for use
- staff must be competent to undertake the compounding
- required facilities and equipment must be available
- safety and appropriateness of the formula of the product must be
ensured
- ingredients are of acceptable quality and from recognised
pharmaceutical suppliers
- products are labelled with all necessary particulars including expiry
date
- special care and attention is given to substances which are hazardous
or need special handling
- records are kept for at least 2 years (these include: formula,
ingredients, quantities used, source, batch number, expiry date, patient
and prescription details, date of dispensing, personnel involved,
identity of resposible pharmcist).
Although these are standards applicable to UK, it is reasonable to
assume that they could be applied equally in any other country.
As the query relates to compounding of essential drugs these would by
definition not include the type of products requiring compounding, ie.
special products for individual patients (and not available from
reputable commercial sources). The most likely need for compounding
would probably be in some hospital pharmacies in response to an unusual
prescription from a specialist consultant (eg. a unique dermatological
preparation). I would expect that the need for compounding in most
community pharmacies would be minimal as virtually all required products
should be commercially available. Also if the the multiple requirements
listed above are to be satisfied, compounding becomes a very costly and
cost-ineffective process, which should therefore not be undertaken
unless there is no alternative.
However, should there still be a need to undertake compounding,
information of many standard formulae can be obtained in earlier
editions of Martindale (pre 29 edition?). It is interesting to note that
later editions do not provide such information (presumably because it is
no longer required?).
Guidance on how to do compounding is contained in the publication
"Pharmaceutical Practice, edited by AJ Winfield and RME Richards, 3rd
edition, Churchill Livingstone 2004 ISBN 0-443-07206-X). Chapter 7,
Dispensing techniques (compounding and good practice) gives detailed
information on the relevant requirements and procedures needed to
undertake satisfactory compounding. It also states that "extemporaneous
dispensing, which cannot be well controlled, should only be used when
such products are not available".
regards
Chris Forshaw
Pharmaceutical Adviser
MoH/Danida Health Sector Programme Support
c/o Royal Danish Embassy
Box 40412-00100, Nairobi, Kenya
Mobile: +254 724 253 202
Tel/fax (home): +254 20 418 2059
Office direct: +254 20 272 4944
forshaw@hsps.or.ke