Q:I have received several prescriptions for amphotericinB capsules to be compounded for patients with"systemic yeast infections." The prescriber specified "amphotericinB oral grade." I cannot find an "oral grade."
A:The question points to the increasing relevance of theUS Pharmacopoeia/National Formulary (USP-NF) to thecompounding pharmacist. The USP Convention makes availablea USP-NF for pharmacists containing fewer drug substancemonographs than the full USP-NF, emphasizing those most likelyto be used in extemporaneous compounding. It also containssections on "Compounding Support Information," "SafeMedication Practices," and others.
Chemicals labeled "USP," "NF," or "USP-NF" are suitable foruse in humans in the United States. The route of administrationis to be determined by the physician and the pharmacist,based on the indication and dosing. In the case of amphotericinB, USP29-NF24 2006 contains 5 different monographs besidesa Reagent Standard: "Amphotericin B," "Amphotericin BCream," "Amphotericin B for Injection," "Amphotericin BLotion," and "Amphotericin B Ointment." No monograph entitled"Amphotericin B for Oral Use" or "Amphotericin B OralGrade" is found. According to the "Amphotericin B" monograph,"Amphotericin B has a potency of not less than 750 μg ofC47H73NO17 per mg, calculated on the dried basis."
The monograph "Amphotericin B for Injection" contains specificlabeling (administration to hospitalized patients only),storage (protected from light and refrigerated), pH (7.2-8.0 inwater), and administration conditions (protect from light).
For compounding a preparation for human administration, theUSP monograph <795>, Pharmaceutical Compounding-Nonsterile Preparations, states that the USP or NF grade substance"is the preferred source of ingredients." If it is not available,the monograph gives alternatives. Your supplier should indicatethat the powder is "for dermatological or oral use," but not that itis "oral grade," because the "grade" is USP, no matter into whatform the product is to be incorporated.
It is important to note, also, that there is little to no absorptionof amphotericin B when administered orally. This factor should beconsidered when administering amphotericin B to patients withsystemic fungal infections.
Mr. Erickson is director of professional affairs at Gallipot Inc.
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