Reconstituting and Labelling a Compounded Cream
A dermatology clinic asks your hospital pharmacy to prepare 100 g of a 2% w/w hydrocortisone cream in a simple oil-in-water base because the commercial product is out of stock. You have hydrocortisone powder, a cetomacrogol emulsifying ointment base, a calibrated electronic balance reading to 0.01 g, a mortar and pestle, and a 100 g ointment jar. The pharmacy has no laminar-flow hood but does have a clean bench. The prescription is for a 6-year-old child with eczema on the face, and the clinic wants it 'today'. The pharmacist is available to supervise.
1. Calculate the quantity of hydrocortisone powder and base needed, and describe the compounding steps and the quality checks you would perform.
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Calculation: 2% w/w means 2 g of hydrocortisone per 100 g of cream.
- Hydrocortisone powder: 2 g (weighed to 0.01 g, i.e. 2.00 g).
- Base: 100 g − 2 g = 98 g. Because the balance reads to 0.01 g, a 2.00 g weigh-out has an acceptable precision for this product. Steps:
- Clean and dry the bench, mortar and pestle; wear gloves.
- Weigh 2.00 g hydrocortisone; levigate with a small amount of base (or a few drops of a suitable liquid) to a smooth paste to break up lumps - a common compounding error is adding powder to a large mass of base, which leaves gritty particles.
- Geometrically incorporate the remaining base in portions, mixing until uniform.
- Transfer to the jar, tapping down to remove air pockets; level the surface.
- Label with the drug, strength (2% w/w), quantity (100 g), batch/preparation date, expiry (assigned by the pharmacist from a stability reference - do not invent one), storage, 'for external use only', and the child's name. Quality checks: visual uniformity and absence of grit; correct final weight (100 g ± acceptable tolerance); correct label; second-person check by the pharmacist; record in the compounding log (ingredients, batch numbers, quantities, preparer, checker, date).
2. The prescription is for a 6-year-old's face. What formulation and counselling considerations must you raise with the pharmacist before release?
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- Potency and site. A 2% hydrocortisone cream is a moderate-strength topical steroid. On a child's face, where the skin is thin and absorption is high, this is a significant choice. The pharmacist should confirm with the prescriber that 2% (rather than 1%) is intended and that the duration is limited; prolonged use on the face risks skin thinning, telangiectasia, and (rarely) systemic absorption.
- Base suitability. Cetomacrogol emulsifying ointment is a reasonable o/w base, but if the eczema is weepy or the child's skin is sensitive, preservative and excipient tolerance should be considered. Confirm the base is appropriate for facial use.
- Quantity. 100 g is a large amount for facial use in a small child; check whether the prescriber intended a smaller quantity to reduce waste and misuse.
- Counselling the parent: apply a thin film only to affected areas, once or twice daily as directed; wash hands before and after (or have the child's carer apply); avoid the eyes and eyelids; do not use under occlusive dressings on the face; stop and seek advice if the skin becomes infected, thins, or the child's condition worsens; keep out of reach of children.
- Labelling: 'For external use only', strength, quantity, expiry, and clear directions. Release only after the pharmacist has reviewed and signed off.