Combination product development—drug-device and beyond

Combination products are the hardest engineering problem in medical device development—not because any single constituent is uniquely complex, but because the interaction between constituents creates engineering challenges that neither the device team nor the drug team has encountered before. The auto-injector that delivers a biologic introduces device-constituent design requirements that affect drug stability, drug constituent formulation requirements that affect device materials selection, and container closure integrity requirements that affect both. A failure in any constituent is a failure of the product.

MANKAIND supports combination product engineering teams by maintaining a unified engineering record that spans constituent boundaries. The traceability between a drug constituent's compatibility requirement and the device constituent's material specification is not a cross-document reference—it is a live connection in the design history that captures the engineering rationale for both decisions.

Primary mode of action: the engineering decision that shapes everything else

The FDA's determination of a combination product's primary mode of action (PMOA) assigns the product to a lead center—CDER, CBER, or CDRH—and determines which regulatory framework governs the submission. But the PMOA analysis is more than a regulatory classification exercise. It requires the engineering team to characterize, in engineering terms, how each constituent contributes to the intended therapeutic effect.

For a drug-eluting stent, the device constituent provides mechanical scaffolding while the drug constituent prevents restenosis—and the relative contribution of each to the intended effect determines the PMOA. For a prefilled syringe system, the device constituent is primarily a delivery mechanism and the drug constituent provides the therapeutic effect, making CDER the likely lead center. For an orthobiologic product that combines a bone graft scaffold with a growth factor, the biological activity of the growth factor may dominate.

MANKAIND supports the PMOA analysis by mapping the intended therapeutic mechanism to the engineering characteristics of each constituent—and by maintaining that mapping as design decisions evolve. When a design change modifies the drug release kinetics or the mechanical performance of the device constituent, the platform flags the potential PMOA implications and prompts the engineering team to assess whether the change affects the regulatory strategy.

Cross-functional traceability: the structural engineering challenge

Combination product development almost always involves separate engineering organizations—a device development team and a pharmaceutical or biologics development team—operating under different development frameworks. The device team works to 21 CFR 820 design controls and ISO 13485. The drug team works to ICH Q8, Q9, and Q10. The organizational frameworks are different, the document types are different, and the vocabularies are different. The regulatory requirement is that the product's development history be coherent and defensible as a whole.

MANKAIND provides the cross-functional traceability infrastructure that combination product teams lack. When the drug team establishes a formulation requirement—a pH range, a preservative concentration, a viscosity specification—MANKAIND creates a traceable connection to the device constituent's design inputs that are affected by that requirement: the primary container material compatibility, the needle gauge selection, the injection force specification. Design changes in either constituent propagate through the traceability matrix to the affected requirements in the other, ensuring that the combination product's design history reflects the actual interdependencies.

Drug-device interaction: the engineering characterization that drives the submission

Container closure integrity, extractables and leachables, drug compatibility, and drug delivery performance are the engineering characterizations that sit at the intersection of the device and drug constituents. Each is an engineering problem—requiring experimental design, analytical method development, and statistical analysis—and each generates submission-critical data that must be integrated into the application.

Extractables and leachables studies are a common source of combination product program delays. The E&L program requires characterizing the chemical entities that can be extracted from the device constituent under controlled conditions, then evaluating which of those extractables are detectable as leachables in the drug product under actual storage conditions, then assessing the toxicological significance of each leachable at its observed concentration. The study design must be established before the container closure system is finalized, because changing the primary container material after the E&L program is complete requires repeating significant portions of the study.

MANKAIND maintains the E&L study design in connection with the device constituent material specifications, so that when material selection decisions are made during device development, their implications for the E&L program are visible to the engineering team. A material substitution that appears minor from a device performance perspective may trigger a full E&L re-evaluation—and MANKAIND surfaces that consequence at the time the decision is made, not after the study program has been completed.

Multiple regulatory frameworks: managing the submission architecture

A combination product application must satisfy the requirements of both the lead center's regulatory framework and the non-lead center's requirements, to the extent applicable. A drug-device combination product with CDER as lead center requires an NDA or BLA that includes a section addressing the device constituent's design controls, biocompatibility, and human factors. The device constituent section of an NDA is evaluated by CDRH reviewers—who apply the same engineering evidence standards they would apply to a standalone device submission.

MANKAIND manages the submission architecture for combination products by maintaining a single engineering record that generates both the device constituent documentation required by CDRH reviewers and the pharmaceutical development documentation required by CDER reviewers. The design history file for the device constituent and the pharmaceutical development report for the drug constituent are generated from the same underlying engineering record—not compiled separately and then reconciled.

Human factors for combination products: the integrated user experience

Combination product human factors studies must address the interaction between the drug constituent and the device constituent in the hands of the intended user. An auto-injector's injection force specification is not just a device engineering requirement—it determines whether a patient with the disease indication (who may have reduced hand strength) can successfully self-administer the drug. The failure mode analysis for a drug-device combination product must include use errors that result in drug delivery failure, not just device malfunction.

MANKAIND integrates the human factors program with the combination product's risk analysis by maintaining the connection between identified use errors, their consequences in terms of drug delivery performance, and the design mitigations implemented in the device constituent. The human factors validation testing protocol is generated from the risk analysis—not designed independently and then reconciled with it.

Combination product development demands engineering intelligence that spans constituent boundaries, regulatory frameworks, and organizational teams. MANKAIND provides that intelligence as a unified platform—connecting every engineering decision across the product to the submission evidence it must ultimately generate.