Compounding an Oral Suspension Without a Preservative
A Delaware community pharmacy receives a prescription for compounded captopril 1 mg/mL oral suspension for a 4-year-old with heart failure. The recipe uses captopril tablets, sterile water, and a commercially available suspending agent that contains no preservative. The pharmacist prepares 120 mL in a clean room and plans to dispense a 30-day supply. The child’s mother says the family will keep the bottle in the refrigerator and will travel to visit grandparents for 3 weeks. The pharmacy’s records show the water was opened 2 months ago and stored at room temperature. The pharmacist must assign a beyond-use date (BUD) and label the product. Delaware has adopted USP compounding standards for pharmacy practice.
1. What beyond-use date should the pharmacist assign, and why?
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The product is a nonsterile, water-containing oral suspension with no preservative. Under USP <795>, the default BUD for a nonpreserved aqueous oral formulation is 14 days when stored in the refrigerator. The pharmacist may assign a shorter BUD if the ingredients or the preparation method warrant it, but may not assign a longer default BUD without a validated stability study or a specific manufacturer’s recommendation that supports the longer date. The presence of a commercial suspending agent does not automatically extend the BUD beyond the default if the final preparation is aqueous and lacks an antimicrobial preservative.
The pharmacist should also address the water. Sterile water that was opened 2 months ago and stored at room temperature should not be used for a compounded oral liquid; the pharmacist should use a fresh supply of purified water or sterile water as appropriate. The intended 30-day supply exceeds the 14-day BUD, so the pharmacist should dispense no more than the amount that can be used within the BUD, provide a second freshly prepared bottle for the remainder if appropriate, or contact the prescriber to adjust the quantity and refill plan. The BUD must be calculated from the date and time of preparation, not from the date the prescription was written.
2. What labeling, counseling, and documentation should accompany the compounded suspension?
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The label should include the patient’s name, the prescription number, the date of preparation, the beyond-use date and time, the storage instruction “refrigerate,” the instruction to shake well, the concentration (1 mg/mL), the dose, the pharmacy’s name and phone number, and the prescriber’s name. Because the preparation is a high-risk pediatric cardiovascular medication, the pharmacist should use metric-only dosing instructions and provide an oral syringe with clear markings. The pharmacist should counsel the mother that the bottle expires before the end of the 30-day supply and that a new bottle must be obtained; the family should not use the product after the BUD even if it looks fine.
Documentation should include the master formula or recipe, the identity and lot numbers of the captopril tablets, water, and suspending agent, the quantity prepared, the date and time of preparation, the assigned BUD, the pharmacist’s initials, and a statement that USP <795> standards were followed. The pharmacist should record the counseling provided and the plan for the remainder of the therapy. If the pharmacy cannot prepare a second bottle during the family’s trip, the pharmacist should coordinate with the prescriber or another pharmacy in advance so the child does not run out of medication.