Home' Australian Pharmacist : July 2011 Contents Vol. 30 -- July #07
old British Pharmaceutical Codex
(BPC 1973) in the hospital dispensary:
Concentrated anise water 1 mL
Chloroform water double
What should this
In the above case, the pharmacist
has already established that there
are no commercially available oral
liquids or suitable therapeutic
alternatives. In the absence of any
current pharmacopoeial formulae,
the safety and appropriateness of
the BPC 1973 formula and excipients
and the availability or source of
active ingredients will need to be
Extemporaneous preparations may
be managed in practice using the
flowchart in Figure 1. It is the role of
the pharmacist to search the literature
for evidence-based formulae and
liaise with the prescriber should a
current pharmacopoeial formula not
Considerations relating to
Isoniazid is the active pharmaceutical
ingredient (API). The solubility of
isoniazid is approximately 1 in 8 and
the pH of an aqueous solution is
• Citric acid and sodium citrate function
as buffers in this formula. They keep
the mixture at an acidic pH to ensure
the stability of the isoniazid; therefore
it is important not to remove
• Concentrated anise water and
compound tartrazine solution function
as flavouring and colouring agents.
However, due to availability and safety
concerns, both of these excipients
can be replaced with suitable
commercially available products,
e.g. Tutti Frutti flavour. Most current
commercially available flavouring
agents are coloured, therefore
a colouring agent is normally
• Glycerol is a sweetener and thickener
(to aid pourability) and has been used
in this formula as an alternative to
syrup. This is due to the established
instability between isoniazid and
sugars such as glucose, fructose,
and sucrose.17 For this reason it is
important to not replace the glycerol
• Chloroform water double strength
is included as a preservative
in this formula. A suitable
replacement preservative may
be methylhydroxybenzoate or
Compound hydroxybenzoate solution
APF21, in appropriate antimicrobial
• Commercial liquid vehicles are
available that contain a combination of
sweeteners, flavours, thickeners and
preservatives. For example, the Ora-
range18 includes Ora-Sweet SF which
consists of purified water, glycerin,
sorbitol, sodium saccharin, xanthan
gum and flavouring, is buffered
with citric acid and sodium citrate,
and preserved with methylparaben
(0.03%), propylparaben (0.008%) and
potassium sorbate (0.1%). Since this
is a non-sugar-containing vehicle, it
could be used in this case (50/50 with
*Ora-Plus is a flavoured sugar free
• Isoniazid is known to crystallise
from solution at low temperatures.
If the final product is refrigerated,
and crystallisation of the isoniazid
occurs, the formulation will need to
be warmed to room temperature to
dissolve the crystals, if required.8
1. Fundamental pharmacy practice. Professional Practice
Standards. Version 4. Pharmaceutical Society of
2. Compounding (also known as Extemporaneous
Dispensing). Professional Practice Standards. Version 4.
Pharmaceutical Society of Australia; 2010.
3. Anderson RA, ed. Australian Pharmaceutical Formulary
and Handbook. 13th Ed. The Pharmaceutical Society of
4. Haywood A, Glass BD. It's all about coal tar. Aus Pharm.
5. van Doorne H, Leijen JB. The preservation of some oral
liquid preparations. The replacement of chloroform by
other preservatives. Pharm World Sci. 1994; 16(1):18--21.
6. Collins-Williams C. Clinical spectrum of adverse
reactions to tartrazine. J Asthma. 1985; 22(3):139--43.
7. Leung A. Encyclopaedia of Common Natural Ingredients
Used in Food, Drugs and Cosmetics. New York, NY: J
Wiley and Sons; 1980.
8. New Zealand Hospital Pharmacists' Association.
Database of oral liquid preparations [online].
PharmInfoTech. Feb 2010 [accessed 7 Jun 2011].
9. Sansom LN, ed. Australian Pharmaceutical Formulary
and Handbook. 21st Ed. Pharmaceutical Society of
10. Martindale: The complete drug reference (electronic
resource). London: Pharmaceutical Press; 2010.
11. Glass BD, Haywood A. Stability considerations in
liquid dosage forms extemporaneously prepared from
commercially available products. J Pharm Pharm Sci.
12. Allen, L. V. Jr. (Editor) International Journal of
Compounding. International Journal of Pharmaceutical
Compounding, Edmond, OK.
13. Allen LVJ. Allen's compounded formulations: the
complete US pharmacist collection. Washington DC:
American Pharmaceutical Association; 2003.
14. Nahata MC, Pai VB, Hipple TF. Pediatric drug
formulations. 5th ed. Cincinnati; 2004.
15. Trissel LA. Trissel's Stability of Compounded
Formulations. 4th ed. Washington, DC: American
Pharmacists Association; 2009.
16. Prankerd RJ. Compounded products -- Stability studies
in Hospital Pharmacy departments. J Pharm Pract Res.
17. Rao KVN, Kailasam S, Menon NK, et al. Inactivation of
Isoniazid by Condensation in a Syrup Preparation. Bull
18. ORA-SWEET SF. At: www.paddocklabs.com/html/
Figure 1. Management of extemporaneous preparations in practice
Commercial product available?
Therapeutic alternative available?
Current pharmacopoeial formula available?
Evidence-based formula available?
• Literature search (journals, books)8--16
• Formula has proven stability (HPLC
• Liaise with prescriber2
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