Matrix: Combination Product Complaint Routing Under 21 CFR Part 4

This is a ready-to-use matrix for deciding which CGMP system governs a combination product’s complaint file, and which provisions of the other system still apply on top of it. Replace every <<FILL: ...>> placeholder and confirm the current text of 21 CFR Part 4 against the regulation before you rely on this. This content is educational reference, not legal or regulatory advice; a genuinely borderline classification should go to Regulatory Affairs, not be resolved by this matrix alone.

Document control header

Field	Entry
Document title	Combination Product Complaint Routing Matrix
Document number	`<<FILL: DOC-ID, e.g. QA-MTX-044>>`
Version	`<<FILL: version>>`
Effective date	`<<FILL: effective date>>`
Document owner	`<<FILL: role, e.g. Head of Quality Assurance>>`
Product(s) covered	`<<FILL: combination product name(s)>>`
Reviewed by	`<<FILL: Regulatory Affairs, QA>>`

1. Why this matrix exists

21 CFR Part 4 lets a combination product with a drug constituent and a device constituent run a single primary CGMP operating system rather than fully satisfying both frameworks independently. Section 4.4(b) names which specific provisions of the other framework still apply on top of the primary system. Complaint handling itself is not on either cross-over list; it stays wherever the primary system puts it. What does cross over, for a drug-primary product, is the device CAPA provision, which has operational consequences for how a complaint investigation has to be closed out even though the complaint record itself stays under the drug rule.

2. Step 1: confirm which system is primary for this product

Question	Answer
Has this product’s primary mode of action (PMOA) and lead center assignment been documented (RFD, PMOA determination, or equivalent)?	`<<FILL: Y/N, reference>>`
Which CGMP operating system does the site’s quality system document as primary for this product?	`<<FILL: 21 CFR 211 (drug-primary) / 21 CFR 820-QMSR (device-primary)>>`
Is that election documented in the site’s quality system (not assumed)?	`<<FILL: Y/N, reference>>`

If the primary system is not documented, stop and resolve that with Regulatory Affairs before routing any complaint; do not let an individual complaint handler make this determination informally.

3. Step 2: route the complaint file itself

Primary system	Complaint file governed by	Notes
Drug-primary (21 CFR 211)	21 CFR 211.198, Complaint files	Standard drug complaint workflow and record content apply.
Device-primary (21 CFR 820 / QMSR)	The device complaint provision (ISO 13485:2016 clause 8.2.2, incorporated by reference under the QMSR, read with the residual Part 820 sections)	Standard device complaint workflow and record content apply.

4. Step 3: apply the cross-over provisions that still bind the other system

If drug-primary (211), these device provisions still apply in full

21 CFR 820 section	Subject	What it means for this complaint
820.20	Management responsibility	`<<FILL: how management review covers this product's quality signals>>`
820.30	Design controls	`<<FILL: relevant only if the complaint implicates a design change>>`
820.50	Purchasing controls	`<<FILL: relevant if the complaint implicates a purchased device component>>`
820.100	Corrective and preventive action	A confirmed device-constituent defect from this complaint must feed a CAPA system meeting the device CAPA provision’s trigger and effectiveness-check expectations, even though the complaint record stays under 211.198.
820.170	Installation	`<<FILL: relevant only if the device constituent requires installation>>`
820.200	Servicing	`<<FILL: relevant only if the device constituent is serviced>>`

If device-primary (820 / QMSR), these drug provisions still apply in full

21 CFR 211 section	Subject	What it means for this complaint
211.84	Component and container/closure testing	`<<FILL>>`
211.103	Calculation of yield	`<<FILL>>`
211.132	OTC tamper-evident packaging	`<<FILL: if applicable>>`
211.137	Expiration dating	`<<FILL>>`
211.165	Testing and release for distribution	`<<FILL>>`
211.166	Stability testing	`<<FILL>>`
211.167	Special testing requirements	`<<FILL>>`
211.170	Reserve samples	`<<FILL>>`

5. Step 4: classify this complaint’s constituent involvement

Question	Answer
Does the complaint implicate the drug constituent only?	`<<FILL: Y/N>>`
Does it implicate the device constituent only?	`<<FILL: Y/N>>`
Does it implicate the interaction between the two (for example, a delivery device that under- or over-doses the drug)?	`<<FILL: Y/N>>`
If drug-primary and the device constituent is implicated and confirmed, has a CAPA been opened meeting 820.100 expectations?	`<<FILL: Y/N, CAPA reference>>`

6. Decision and rationale

Field	Entry
Complaint number	`<<FILL>>`
Primary system	`<<FILL>>`
Complaint file routed to	`<<FILL: 211.198 or device complaint provision>>`
Constituent(s) implicated	`<<FILL>>`
Cross-over provision(s) triggered	`<<FILL: e.g. 820.100 CAPA>>`
CAPA reference, if triggered	`<<FILL>>`
Decided by (name, role, date)	`<<FILL>>`

7. References

21 CFR Part 4, Regulation of Combination Products, sections 4.3 and 4.4. 21 CFR 211.198, Complaint files (drug). 21 CFR 820.198 (device complaint provision, residual) and ISO 13485:2016 clause 8.2.2 (incorporated by reference under the QMSR effective 2 February 2026). 21 CFR 820.100, Corrective and preventive action.

Confirm the current version of every citation before issue; the QMSR transition in particular changed section numbering for several device provisions.

Filled specimen

A pre-filled auto-injector combination product (drug-primary, per the site’s documented PMOA determination) receives a complaint that the injector fired but delivered a visibly incomplete dose.

Field	Entry
Complaint number	CMP-2026-05102
Primary system	Drug-primary (21 CFR 211), per RFD-2019-0442
Complaint file routed to	21 CFR 211.198
Constituent(s) implicated	Device (injector mechanism) and the interaction (incomplete dose delivered)
Cross-over provision(s) triggered	820.100 (CAPA), because the device constituent is implicated and, on investigation, confirmed
CAPA reference	CC-2026-0309, injector plunger seal tolerance, root cause traced to a supplier component drift
Decided by	T. Osei, QA Complaint Coordinator, 11 Oct 2026

The complaint record itself lives entirely under 211.198, exactly as it would for a drug-only complaint. What changed is the CAPA: because the confirmed defect sat in the device constituent, the CAPA investigation and effectiveness check had to satisfy 820.100’s more prescriptive expectations (a documented root cause investigation, defined corrective and preventive actions, and a verified effectiveness check against the recurrence), on top of whatever the site’s standard drug CAPA procedure already required. Complaint intake and the complaint file format never changed; the CAPA that the complaint fed into did.

Common inspection findings this matrix prevents

A combination product complaint handled purely under the drug procedure, with the device constituent’s CAPA cross-over provision never engaged when a device defect was confirmed.
No documented determination of which system is primary, so different complaint handlers apply different rules to the same product over time.
A device-primary product’s drug-constituent testing and release provisions (211.84, 211.165, and related sections) never checked when a drug-constituent defect is alleged.

How to adapt this matrix

Confirm and document your product’s PMOA determination and primary-system election before using this matrix operationally; this document assumes that determination already exists.
Fill in the <<FILL>> cells in Sections 4 and 5 with the specific device or drug provisions genuinely relevant to your product’s constituent parts; delete rows that plainly do not apply (for example, 820.170 Installation for a product with no installed device component).
Route a genuinely borderline PMOA or cross-over question to Regulatory Affairs rather than resolving it at the complaint-handler level.