How do the newly revised General Chapters <661.1> and <661.2> impact currently marketed packaged pharmaceutical products?

In order to market a drug product, defined as a dosage form plus its associated packaging system, the product must be evaluated for its suitability for use by the relevant regulatory authority. The purpose of <661.1> is to increase the likelihood that a packaging system will be suited for use by providing data about its material(s) of construction, whereas the purpose of <661.2> is to establish that the packaging system is suited for use. Because suitability for use has already been established for marketed products via regulatory review, <661.1> and <661.2> testing has no additional value in terms of establishing suitability for use. Thus, a packaging system and its materials of construction that have been evaluated by a regulatory authority and are used with a marketed dosage form are considered to already meet the requirements of <661.2> and <661.1> (see <1661> Evaluation of Plastic Packaging Systems and Their Materials of Construction with Respect to Their User Safety Impact and Table 1).

If a packaging system or component that gained regulatory approval with one product is used as a packaging system for a new product, would <661.1> and/or <661.2> testing be required?

If a packaging system (and its materials of construction) that is used with one marketed dosage form is used with a second, compositionally similar dosage form, and if the conditions of use are similar for the two dosage forms, neither <661.1> nor <661.2> testing is required. This is because the information used to establish the suitability for use with the approved product is relevant to and is typically sufficient for establishing the suitability for use with the new product.

If the new drug product is compositionally different from the approved product, and/or the conditions of use are different, then <661.1> testing would not be required. This is because generally, <661.1> testing is not dependent on the dosage form composition or the conditions of use.

The exception to this statement is when a packaging system for a marketed “low-risk” dosage form is used for a new “high-risk” dosage form. A dramatic change in the nature of the dosage form would require <661.1> testing. This is because <661.1> testing of materials used with “high-risk” dosage forms is more extensive than <661.1> testing of materials used with “low-risk” dosage forms. In this scenario, those tests that are required for both low- and high-risk dosage forms do not need to be repeated (for example, Identity, Physicochemical Tests, Extractable Metals, and <87> Biological Reactivity Tests, In Vitro). Those tests that are unique to the high-risk dosage forms (e.g., <88> Biological Reactivity Tests, In Vivo as appropriate and Plastic Additives) would need to be performed.

A similar analysis is true for <661.2> testing of the packaging system. Biological Reactivity and Physicochemical Tests are not specifically linked to a dosage form or conditions of contact, thus the packaging system would not need to be tested for these attributes regardless of any differences in the composition or conditions of use between the approved and new drug products. However, as the generation and toxicological safety assessment of an extractables profile is influenced by the composition of the dosage form and the conditions of use, it may be necessary to perform the Chemical Safety Assessment (extractables profiling and toxicological safety) in <661.2>. Under <661.2>, any decision not to perform this Chemical Safety Assessment would need to be justified on a case-by-case basis.

When a packaging system for a marketed “high-risk” dosage form is used for a new “low-risk” dosage form, <661.1> and <661.2> testing is not necessary. In this case, whatever information was used to establish the suitability for use with the “high-risk” dosage form would also establish the suitability for use with the “low-risk” dosage form, as the “high-risk” information would generally represent a worst case scenario for the “low-risk” situation (see <1661> Evaluation of Plastic Packaging Systems and Their Materials of Construction with Respect to Their User Safety Impact and Table 1).

If a material of construction for a packaging system or component that has received regulatory approval is changed, is <661.1> and/or <661.2> testing required?

As all materials of construction are required to meet <661.1>, it is expected that the new, different material would have to have been tested per <661.1>. Note that the new material would not be one of the legacy materials whose <661.1> compliance is “covered” by the fact that the product is being marketed.

Use of a new and different material of construction in a packaging system can reasonably be anticipated to have an effect on the suitability for use of that packaging system. Thus, the new packaging system should be tested per <661.2>.

Nevertheless, neither <661.1> nor <661.2> is intended to establish prescriptive requirements associated with exercising change control. Organizations are responsible for establishing their own change control practices, subject to approval by the appropriate regulatory authority. It is expected that those change control practices that do not specifically utilize <661.1> and <661.2> will include a justification for such practices, specifically focusing on the potential effect(s) that the change may have on user safety and product quality (see <1661> Evaluation of Plastic Packaging Systems and Their Materials of Construction with Respect to Their User Safety Impact and Table 1).

Table 1. Guidance for Situations where <661.1> and <661.2> Testing would be Applicable

Note: The provisions in <661.2> for packaging systems must be met for components whose testing has been deemed to be necessary.

Why does USP require <87> Biological Reactivity Tests, In Vitro testing for solid oral dosage forms?

In general, the amount and type of testing required to verify the suitability of packaging systems and their materials of construction should be consistent with the risk that the system or material could be unsuitable. In addition, the risk that packaging systems would be unsuited for use for solid oral dosage forms is lower than the risk associated with other dosage forms. Recognizing these generalizations, <661.1> has different testing requirements and/or specifications for these two groups of dosage forms. Because some of the tests required in <661.1> are applicable regardless of dosage form (for example, Identity, Physicochemical Tests, and Extractable Metals), such tests are applied with no difference to both groups of dosage forms. Although both groups of dosage forms are required to address Biological Reactivity, <661.1> requires only Biological Reactivity Tests, In Vitro <87> for oral and topical dosage forms while requiring both Biological Reactivity Tests, In Vitro <87> and Biological Reactivity Tests, In Vivo <88> (as applicable) for all other dosage forms. Both groups are required to address Plastic Additives, but solid oral dosage forms address this aspect by making proper reference to FDA’s Indirect Food Additive regulations while the other dosage forms address this issue by specified Plastic Additives testing.

A cornerstone of suitability for use assessment of packaging systems and their materials of construction is the concept of orthogonal assessment. This is because individual means of assessment are generally insufficiently robust or broad enough in scope to provide rigorous and complete assessments on their own. Thus orthogonal assessments are performed to essentially “fill in the gaps” in the individual assessments.