Research
The one injectable label that carries an aluminum number
Drug labeling rules almost never put a contaminant limit on a container. One section does, for one narrow class of injectable, and reading why shows how specific a labeling requirement has to be before it exists at all.
A number on a label, which is rarer than it sounds
Most drug labeling rules govern format, wording and which sections must appear. Very few put a specific measured quantity of a contaminant onto a container.
Section 201.323 of title 21 does. Its heading names its own boundaries: Aluminum in large and small volume parenterals used in total parenteral nutrition.
Total parenteral nutrition is intravenous feeding, where a person receives nutrition through a vein over long periods rather than by eating. Large volume and small volume parenterals are the bags and vials that make up such a mixture.
A word-bounded search of every section of the fetched part 201 found this one section and no other mentioning aluminum. The same search over the fetched part 111 and part 207 returned none. That census covers those three parts and no more.
What the section actually requires
It sets a hard ceiling for one product class. "The aluminum content of large volume parenteral (LVP) drug products used in total parenteral nutrition (TPN) therapy must not exceed 25 micrograms per liter."
It then puts that fact on paper. The package insert for such products "must state that the drug product contains no more than 25 µg/L of aluminum," in the Precautions section of the labeling.
For small volume parenterals and pharmacy bulk packages used to prepare TPN solutions, the requirement moves to the container itself. The maximum level present at expiry "must be stated on the immediate container label," in a prescribed form beginning with the words Contains no more than.
Lyophilized powders get their own prescribed sentence, phrased around what the concentration will be after reconstitution according to the package insert instructions.
The number on the label is a worst case, not an average
Paragraph (c) tells manufacturers which figure to print, and it is deliberately conservative.
The maximum level stated "must be stated as the highest of" three candidates.
The first is "The highest level for the batches produced during the last 3 years."
The second is "The highest level for the latest five batches."
The third is a historical maximum, applicable only for a defined transitional period after a date named in the regulation.
A manufacturer whose maximum is at or below the ceiling gets a simplification. Instead of the exact amount, the label "may state" the fixed phrase declaring no more than 25 µg/L of aluminum.
The warning, and who it is written about
Paragraph (e) prescribes a warning that must appear in the Warnings section of the labeling for all covered products. Its exact words are set by the regulation.
It opens: "WARNING: This product contains aluminum that may be toxic. Aluminum may reach toxic levels with prolonged parenteral administration if kidney function is impaired."
It then names the group it is most concerned with. "Premature neonates are particularly at risk because their kidneys are immature, and they require large amounts of calcium and phosphate solutions, which contain aluminum."
And it gives the basis, naming a threshold. It cites research on "patients with impaired kidney function, including premature neonates, who receive parenteral levels of aluminum at greater than 4 to 5 µg/kg/day." Those patients "accumulate aluminum at levels associated with central nervous system and bone toxicity."
The warning closes with a caution against reading that threshold as a safe line: "Tissue loading may occur at even lower rates of administration."
Two conditions run through it, and both are about the situation rather than the molecule. Prolonged administration, and impaired kidney function.
Measuring it is not left to judgment either
Paragraph (f) closes the loop between the label claim and the laboratory.
Applicants and manufacturers "must use validated assay methods to determine the aluminum content in parenteral drug products," and those methods "must comply with current good manufacturing practice requirements."
For products under an approved application, validation of the method and release data for several batches go to the agency.
For products without one, the obligation is different in kind. Manufacturers "must make assay methodology available to FDA during inspections."
That last sentence is the interesting one for this market. The rule contemplates parenteral products that are not the subject of an approved application, and reaches them through inspection rather than through a filing.
What this does not say about a peptide vial
It is important to be exact here, because a rule this specific is easy to over-read in either direction.
By its own terms the section reaches large volume parenterals used in TPN therapy, and small volume parenterals and pharmacy bulk packages used in the preparation of TPN solutions. A peptide vial intended for subcutaneous injection is not described by that language.
So a peptide label carrying no aluminum statement is not thereby non-compliant with this section. The section is not addressed to it.
The converse is equally true and more useful. The absence of an aluminum figure on a vial tells a reader nothing about its aluminum content, because nothing required the figure to be there.
What the section demonstrates is the shape of the problem. A numeric contaminant declaration on an injectable exists where a specific rule created it, for a specific product class, after a specific finding. It does not arise from general good practice.
What was not verified
No product was tested and no label was examined for this piece. The subject is the regulation.
The census behind the sentence about part 201 having one aluminum provision was run over the fetched text of parts 201, 111 and 207 only. No claim is made about the rest of title 21.
Nothing here is medical advice, and nothing here should be read as guidance about kidney function, dosing or the safety of any product. The warning quoted above is a label requirement written for clinicians, quoted so a reader can see what a real contaminant warning looks like.
Key takeaways
- Section 201.323 is a rare case of a drug labeling rule stating a numeric contaminant limit.
- It reaches only parenterals used in, or used to prepare, total parenteral nutrition.
- A stated aluminum maximum is a worst case drawn from three defined candidates, not an average.
- The prescribed warning turns on prolonged administration and impaired kidney function, and names premature neonates.
- Assay methods must be validated, and for unapproved products are checked at inspection rather than by filing.
- A vial with no aluminum figure is not non-compliant and is not thereby known to be low in aluminum.
Frequently asked questions
What does section 201.323 cover?
Two things. Large volume parenteral drug products used in total parenteral nutrition therapy must not exceed 25 micrograms of aluminum per liter, and must state that in the Precautions section of the package insert. Small volume parenterals and pharmacy bulk packages used to prepare TPN solutions must state the maximum level present at expiry on the immediate container label, in a prescribed form.
Is the number on such a label a typical value?
No, it is a worst case. Paragraph (c) requires the stated maximum to be the highest of three candidates. Those are the highest level for batches produced during the last three years, the highest level for the latest five batches, and a historical maximum applicable only for a defined transitional period. Where that maximum is at or below the ceiling, the label may instead carry the fixed phrase declaring no more than 25 micrograms per liter.
What does the required warning say?
It states that the product contains aluminum that may be toxic, and that aluminum may reach toxic levels with prolonged parenteral administration if kidney function is impaired. It identifies premature neonates as particularly at risk because their kidneys are immature. It cites research on patients with impaired kidney function receiving parenteral aluminum above a stated daily threshold, who accumulate levels associated with central nervous system and bone toxicity. It adds that tissue loading may occur at even lower rates.
Should a peptide vial carry an aluminum statement?
Not under this section. By its own terms it reaches large volume parenterals used in TPN therapy and small volume parenterals and pharmacy bulk packages used in preparing TPN solutions. A vial intended for subcutaneous injection is not described by that language. The useful consequence runs the other way: the absence of an aluminum figure on such a vial says nothing about its aluminum content, because no rule required the figure.
Does this reach products without an approved application?
Paragraph (f) contemplates them. Applicants and manufacturers must use validated assay methods complying with current good manufacturing practice requirements. Where a product is the subject of an approved application, method validation and release data for several batches go to FDA. Where it is not, the manufacturer must make assay methodology available to FDA during inspections instead.
Sources
Each document below is named as it names itself, with the date printed on that document rather than the day it was read.
- Title 21 Code of Federal Regulations section 201.323, Aluminum in large and small volume parenterals used in total parenteral nutrition — Electronic Code of Federal Regulations, Office of the Federal Register, June 2003