Serialization and Traceability: The Drug Supply Chain Security Act (DSCSA)

A blister package used for tablets, capsules, lozenges, and unit-dose pharmaceutical products.

Overview and purpose

The Drug Supply Chain Security Act (DSCSA) establishes a federal framework to build an interoperable, electronic system to identify and trace certain prescription drugs as they are distributed in the United States. At its core, DSCSA requires stakeholders across the pharmaceutical supply chain—manufacturers, repackagers, wholesale distributors, dispensers, and third-party logistics providers—to capture and exchange standardized product and transaction information so that products can be authenticated, traced, and rapidly located in the event of a recall, investigation, or suspected illegitimate product.

Key data elements and the product identifier

Under DSCSA-aligned serialization practices, the minimum essential data elements associated with a serialized package typically include the Global Trade Item Number (GTIN) and a unique serial number. In practice, the product identifier (PI) used for traceability is often implemented as a GS1-compliant data structure that contains the GTIN and a unique serial number encoded in a 2D barcode (commonly a Data Matrix). In addition to the GTIN and serial number, many supply chain partners capture lot (batch) number and expiration date because these elements are necessary for product management, recalls, and safety vigilance. When printed on packaging or carried in electronic exchange messages, these elements allow precise identification of an item at the package (or unit) level.

Applying unique identifiers to blisters and cartons

Applying the PI to pharmaceutical products can occur at different packaging levels depending on product presentation and business practice. For blister-packed products this means one of two common approaches:

• Unit or blister-strip level serialization: Each blister strip (for example, a strip of 6 or 10 tablets) is assigned its own unique identifier consisting of GTIN + serial number, and the PI is printed on the strip or its immediate lidding foil. This provides the highest granularity for track-and-trace and is common in markets or use-cases (hospitals, institutional dispensing) where unit-dose control is critical.
• Carton or pack level serialization: Each outer carton that contains one or more blister strips receives the PI. The carton is the serialized saleable unit and is typically what is scanned in distribution and pharmacy settings. In many retail scenarios, carton-level serialization is the default because it balances traceability with packaging line throughput and cost.

When the PI is applied to blister strips, practical considerations include limited print area, surface curvature, and the need for robust, readable codes. Common solutions are 2D Data Matrix codes printed on lidding foil or on an adhesive label affixed to the blister strip, combined with human-readable GTIN/serial/lot/expiry text adjacent to the barcode. For cartons, 2D barcodes are typically printed on a panel that is verified during packaging line operations.

Aggregation: linking child and parent packaging

Aggregation is the process that links multiple child items (for instance, serialized blister strips or serialized cartons) to a parent container such as a case or pallet. Aggregation establishes a parent-child relationship that enables efficient scanning and data exchange when multiple units move through the supply chain together. Instead of scanning each serialized unit individually at every checkpoint, a distribution center can scan the parent case or pallet barcode which implicitly represents the set of serialized children it contains.

Practically, aggregation records include the parent identifier (often a GS1 Serial Shipping Container Code or SSCC for cases/pallets) and the list of child PIs (GTIN + serials, and optionally lot/expiry). Those parent-child linkages are stored in local serialization/aggregation systems (often an MES, WMS, or dedicated serialization database) and are transmitted to trading partners or made available via standardized electronic messages.

Standards and data exchange

To achieve interoperable electronic traceability, DSCSA-aligned implementations commonly rely on global data standards such as GS1 and international messaging frameworks. The Electronic Product Code Information Services (EPCIS) standard is often used to represent and exchange events that describe the movement and change of state of products (e.g., commissioning/serial assignment, packing/aggregation, shipping, receiving). EPCIS events can carry the PI, lot, expiry, location, timestamp, and parent-child relationships needed to support tracing queries.

Operational considerations and best practices

• Packaging line integration: Integrate serialization printers, vision inspection, and aggregation scanners early in the packaging line design. Verify print quality and barcode readability with production-grade readers.
• GS1 compliance: Use GS1 identifiers and data formats for GTIN, SSCC, and application identifiers to ensure compatibility with trading partners and EPCIS-based exchanges.
• Aggregation strategy: Determine whether aggregation will be performed at the blister-to-carton, carton-to-case, and/or case-to-pallet levels. Store parent-child records with timestamps and operator/audit information.
• Data management: Maintain a single source of serialized master data in ERP/WMS/serialization platforms and reconcile data frequently to minimize discrepancies between physical inventory and electronic records.
• Testing and onboarding: Conduct interoperability tests with trading partners and participate in industry pilot programs. Validate electronic exchange formats and timing to meet regulatory expectations.

Benefits

Proper serialization and aggregation deliver multiple tangible benefits: rapid and accurate recall execution by pinpointing affected units, stronger protection against counterfeiting, streamlined returns processing, improved inventory visibility, and reduced manual scanning errors during distribution operations.

Common challenges

Challenges include limited print space on small blister strips, the capital cost of line retrofits, data volume and storage for unit-level records, and the need for secure, authenticated data exchanges with trading partners. Aggregation accuracy is critical—incorrect parent-child mappings can undermine traceability even when individual items are serialized. Organizations should also consider cybersecurity and data privacy when designing data exchange services.

Real-world example

A mid-size pharmaceutical manufacturer produces an antidepressant in 10-tablet blister strips, packed 10 strips per carton. To comply with DSCSA-aligned track-and-trace practices, the company prints a GS1 Data Matrix on each carton containing GTIN + serial + lot + expiry and also applies a serialized identifier on each blister strip because their hospital customers require unit-dose traceability. On the packaging line, a vision system verifies every Data Matrix, a serialization server records each child-to-parent mapping when strips are aggregated into cartons, and the WMS records carton SSCCs assigned to outbound pallets. Trading partners exchange EPCIS events that include commissioning (serial assignment), aggregation (carton composition), and shipment events so that the entire chain can query provenance and perform a rapid targeted recall if needed.

Summary

DSCSA-driven serialization and traceability are achieved by applying standardized product identifiers (GTIN + serial) and, frequently, lot and expiry data to packages and blister strips, coupled with aggregation practices that relate unit, case, and pallet levels. Implementing these capabilities requires careful packaging engineering, adherence to GS1/EPCIS standards, robust data management, and collaborative testing with trading partners to realize the safety and supply-chain benefits.