21 CFR 211.170: Reserve samples

Requires manufacturers to retain identified reserve samples of each active ingredient lot and each drug product lot, at least twice the quantity needed for testing, stored appropriately, visually examined annually, and kept through specified post-expiry periods.

Part 211, Current Good Manufacturing Practice for Finished Pharmaceuticals · Subpart I, Laboratory Controls

4%

of drug-manufacturing 483s since 2023 cite this section at least once

How FDA words it

The opening lines investigators use most when they cite 211.170, from the 483s we hold.

Reserve samples from representative sample lots or batches of drug products selected by acceptable statistical procedures are not examined visually at least once a year for evidence of deterioration.Most used
Reserve drug product samples are not retained and stored under conditions consistent with product labeling.211.170(b)
A sample which is representative of each lot in each shipment of each active ingredient is not retained.211.170(a)

Cited over time

483s citing 211.170, by year

Most citations in 2023. Bars are relative to the busiest year. *2026 to date.

Years shown: 2017 to 2026. The busiest year was 2023.

Recent 483s citing 211.170

See all 483s citing 211.170

The regulation text

§ 211.170 Reserve samples.

(a)An appropriately identified reserve sample that is representative of each lot in each shipment of each active ingredient shall be retained. The reserve sample consists of at least twice the quantity necessary for all tests required to determine whether the active ingredient meets its established specifications, except for sterility and pyrogen testing. The retention time is as follows:

(1)For an active ingredient in a drug product other than those described in paragraphs (a) (2) and (3) of this section, the reserve sample shall be retained for 1 year after the expiration date of the last lot of the drug product containing the active ingredient.

(2)For an active ingredient in a radioactive drug product, except for nonradioactive reagent kits, the reserve sample shall be retained for:

(i)Three months after the expiration date of the last lot of the drug product containing the active ingredient if the expiration dating period of the drug product is 30 days or less; or

(ii)Six months after the expiration date of the last lot of the drug product containing the active ingredient if the expiration dating period of the drug product is more than 30 days.

(3)For an active ingredient in an OTC drug product that is exempt from bearing an expiration date under § 211.137, the reserve sample shall be retained for 3 years after distribution of the last lot of the drug product containing the active ingredient.

(b)An appropriately identified reserve sample that is representative of each lot or batch of drug product shall be retained and stored under conditions consistent with product labeling. The reserve sample shall be stored in the same immediate container-closure system in which the drug product is marketed or in one that has essentially the same characteristics. The reserve sample consists of at least twice the quantity necessary to perform all the required tests, except those for sterility and pyrogens. Except for those for drug products described in paragraph (b)(2) of this section, reserve samples from representative sample lots or batches selected by acceptable statistical procedures shall be examined visually at least once a year for evidence of deterioration unless visual examination would affect the integrity of the reserve sample. Any evidence of reserve sample deterioration shall be investigated in accordance with § 211.192. The results of the examination shall be recorded and maintained with other stability data on the drug product. The retention time is as follows:

(1)For a drug product other than those described in paragraphs (b) (2) and (3) of this section, the reserve sample shall be retained for 1 year after the expiration date of the drug product.

(2)For a radioactive drug product, except for nonradioactive reagent kits, the reserve sample shall be retained for:

(i)Three months after the expiration date of the drug product if the expiration dating period of the drug product is 30 days or less; or

(ii)Six months after the expiration date of the drug product if the expiration dating period of the drug product is more than 30 days.

(3)For an OTC drug product that is exempt for bearing an expiration date under § 211.137, the reserve sample must be retained for 3 years after the lot or batch of drug product is distributed.

[48 FR 13025, Mar. 29, 1983, as amended at 60 FR 4091, Jan. 20, 1995; 89 FR 51770, June 18, 2024]

Questions

What does 21 CFR 211.170 require?

Requires manufacturers to retain identified reserve samples of each active ingredient lot and each drug product lot, at least twice the quantity needed for testing, stored appropriately, visually examined annually, and kept through specified post-expiry periods.

How often is 211.170 cited in Form 483s?

It appears in about 4% of the drug-manufacturing 483s we hold from 2023 onward.

How do FDA investigators word a 211.170 observation?

The most common opening is: “Reserve samples from representative sample lots or batches of drug products selected by acceptable statistical procedures are not examined visually at least once a year for evidence of deterioration.”

Which sections are cited alongside 211.170?

In the same 483s, investigators most often also cite 211.22 (Responsibilities of quality control unit), 211.192 (Production record review), 211.160 (General requirements), 211.67 (Equipment cleaning and maintenance).