Independent learning for medical-device professionals
SearchCommentaryConsulting
Worked Examples & Case StudiesMTL-407 · WORKED PRODUCT CASE STUDY

Combination Product

An end-to-end example showing how medicinal-product, device, usability and manufacturing evidence combine into one treatment-delivery argument.

How to use this case study

This simplified example follows a pre-filled autoinjector as one therapeutic system. Ask whether dose, formulation, container, delivery mechanism, user interaction and production controls support the same clinical use across organisational boundaries.

01

Case at a glance

A single-dose pre-filled autoinjector delivers a fixed volume of a biological medicinal product subcutaneously. An adult patient or carer removes the cap, places the device against the skin and initiates delivery. The device provides start and completion feedback and shields the needle after use.

Therapeutic value

Reliable self-administration of the prescribed medicinal product outside the clinic.

Combination boundary

Drug formulation, primary container, delivery device, labelling, packaging and user workflow.

Principal uncertainty

Whether drug and device interactions remain acceptable through shelf life and use.

Organisational challenge

Evidence is created by pharmaceutical, device, supplier, clinical and manufacturing teams.

02

Define the therapy and delivery claim together

Draft intended purpose

The product is intended for single subcutaneous administration of a specified fixed dose of the medicinal product by adult patients or carers following prescription and training. It is supplied pre-filled for use in the stated population and use environment.

The dose, viscosity, injection time, population, body site, storage, preparation and user determine both pharmaceutical and device requirements. Apply MTL-102 — Intended Purpose, Users and Use Environments.

03

Draw one combination-product boundary

Medicinal productStrength, formulation, stability, particles and compatibility
Primary containerClosure, integrity, extractables, delivery force and dimensions
Delivery deviceActivation, drive, needle path, dose delivery, feedback and shielding
User interfaceStorage, preparation, placement, activation, confirmation and disposal
ManufacturingFilling, assembly, inspection, packaging and release
Clinical systemPrescription, training, administration, adherence and pharmacological effect
04

Translate therapy into device requirements

  • The system shall deliver the specified dose volume within the approved time and accuracy limits across claimed conditions.
  • The device shall accommodate the approved container and formulation properties throughout shelf life.
  • Activation shall not occur before correct placement under foreseeable handling.
  • Completion feedback shall correspond to the defined delivery state and shall not overstate delivery into the body.
  • The needle shall remain protected before use and become shielded after withdrawal.
  • Storage excursion, visible damage or expired product shall be identifiable and handled by clear instructions.
  • Critical drug, container and device configurations shall be uniquely controlled and traceable.
05

Analyse treatment failure across constituents

Under-delivery

Viscosity, force, obstruction, early removal or mechanism failure reduces delivered volume. Control design margins, feedback and instructions.

Degraded medicine

Material interaction, temperature or agitation affects product quality. Control compatibility, storage, transport and shelf life.

Needlestick

Premature exposure or failed shielding injures a user. Use passive protective design and representative verification.

Use error

The patient misinterprets preparation or completion. Simplify the interface and validate critical tasks.

A single risk analysis must connect device failure and use error to therapeutic consequence. Apply MTL-114 — Medical-device Risk Management.

06

Assign ownership without fragmenting the product

A combination governance team owns the integrated intended purpose, risk position, configuration, evidence plan and change assessment. Pharmaceutical teams lead formulation and drug-product evidence; device teams lead mechanism and delivery performance; human-factors teams lead the user interface; manufacturing and supplier teams control the realised combination. Interface agreements define inputs, outputs, approval and escalation.

Systems engineering provides the integrating logic using MTL-105 — Systems Engineering, Architecture and Interfaces.

07

Build evidence around the final combination

DRUG

Medicinal-product quality

Identity, strength, purity, stability, particles, container closure and handling.

DEVICE

Delivery performance

Dose accuracy, injection time, activation, forces, feedback, needle safety and robustness.

INTERFACE

Compatibility

Dimensions, materials, silicone, break-loose and glide forces, viscosity, ageing and transport.

USE

Human factors and clinical use

Critical tasks, training, comprehension, simulated use and relevance to clinical evidence.

Representative evidence should reflect the final formulation, container, device and instructions. See MTL-315 — ISO 11608 Needle-based Injection Systems.

08

Follow one dose-delivery thread

Clinical needReceive the prescribed therapy reliably at home
HazardIncomplete delivery reduces therapeutic effect
RequirementDeliver the specified volume across formulation and use conditions
ImplementationContainer, drive system, needle path, feedback and instructions
VerificationAccuracy, time, force, ageing, temperature and interruption testing
ValidationRepresentative users complete critical tasks and interpret feedback
09

Release the exact combination

Transfer covers drug-product batch, container components, device parts, assembly, labelling, packaging, in-process controls and final acceptance. Release documentation links the approved constituent versions and confirms that production evidence represents the same combination used in verification, validation and stability studies.

10

Use a formulation change to test lifecycle control

A higher-concentration formulation reduces injection volume but increases viscosity. The team must reassess container compatibility, delivery force and time, dose accuracy, device margins, user feedback, stability, manufacturing, human factors, clinical evidence and regulatory strategy. Reusing the same device platform does not make the new combination unchanged.

Every constituent change requires an integrated impact assessment against the approved treatment-delivery argument.

DISCUSSION

Questions to challenge the case

  1. Who owns the integrated combination-product risk position?
  2. Which drug properties become device design inputs?
  3. What does completion feedback actually prove?
  4. Which evidence must use the final aged combination?
  5. How are supplier and constituent changes assessed together?
  6. What configuration identifies the product tested and released?