Blister & Pharma Packaging · The Complete Guide

A pharmaceutical blister pack consists of a formed plastic or foil cavity (the blister) that holds an individual dose of a solid dosage form (tablet, capsule, or lozenge), sealed with a flat lidding foil. The patient pushes the tablet through the lidding foil to access the dose, the push-through action being the defining user interaction of the blister format. This individual-dose packaging provides tamper evidence, product identification at the unit level, dose-counting capability, and moisture and oxygen protection, all critical requirements for solid-dose pharmaceutical packaging.

India is one of the world's largest pharmaceutical markets and a major global pharmaceutical manufacturer. The Indian pharmaceutical blister packaging market is estimated at ₹6,000–8,000 crore annually. Nearly all solid dosage pharmaceutical products sold in India are blister-packaged, making blister packaging the dominant pharmaceutical packaging format by volume. The Indian pharma packaging industry serves both the domestic market and a very significant export market, primarily to regulated markets in the EU, US, UK, and the Gulf, where packaging compliance standards are stringent.

The forming film is the base material that is thermoformed into the blister cavity shape. It must be formable (able to be heated and shaped without cracking or thinning excessively), provide the required moisture and oxygen barrier, be compatible with the pharmaceutical product, and be peelable or push-through as required by the product's opening specification. The choice of forming material is a pharmaceutical engineering decision, it must be validated through stability studies before commercial production.

PVC · Polyvinyl Chloride (standard blister film)

PVC is the most widely used blister forming film in India and globally. Rigid pharmaceutical-grade PVC is formable, clear (allowing tablet visibility), and relatively economical. Its moisture barrier is moderate, adequate for most solid dosage forms under ambient storage conditions, but insufficient for moisture-sensitive formulations.

PVDC · Polyvinylidene Chloride

PVDC is not used as a standalone blister film, it is applied as a coating on PVC or as a layer in multi-layer films. PVDC is an excellent barrier to both moisture vapour and oxygen, significantly better than PVC alone. The barrier increases with coating weight: a 90 GSM PVDC coat reduces MVTR by approximately 5–10× versus uncoated PVC. PVDC-coated PVC is the standard specification for many branded Indian pharmaceutical products requiring enhanced moisture protection.

The lidding foil is the flat aluminium foil layer heat-sealed to the top of the forming film across all blister cavities. It is the printed surface of the blister pack, carrying the product name, strength, batch number, manufacturing date, expiry date, dosage instructions, drug schedule symbol, and barcode. The lidding foil must provide a complete moisture and light barrier (aluminium foil has effectively zero MVTR and OTR), must bond reliably to the forming film under heat sealing, and must allow the patient to push through or peel the foil to access the tablet.

Standard lidding foil construction

Standard pharmaceutical lidding foil in India is a three-layer laminate: Hard temper aluminium foil (20–25 micron) / Heat-seal lacquer / Print primer and printing inks. The foil face is printed by offset or gravure; the inner face is coated with a heat-seal lacquer that bonds to the forming film when heated and pressed. The heat-seal lacquer formulation must be matched to the forming film material, PVC heat-seal lacquer is different from PVDC-compatible lacquer.

Push-through vs peel-off lidding

• Push-through (PT) foil, the patient presses the tablet through the foil by applying finger pressure directly over the cavity. The foil punctures cleanly. Standard for most tablet and hard capsule applications. Push-through force must be within the specified range, too high and elderly or arthritic patients cannot access their dose; too low and the seal is inadequate.
• Peel-off (PO) foil, the foil is designed to peel from the forming film without push-through. A corner tab allows the patient to start the peel. Used for soft gelatin capsules (which are too soft to push through foil) and for applications where the patient should remove the tablet from the cavity before swallowing (some paediatric formulations).
• Child-resistant (CR) foil, requires both push and peel in a specific sequence to access the dose, push down while simultaneously peeling. Mandatory for certain drug schedules and strongly recommended for toxic or abuse-potential medications. Child-resistant blisters require validation testing against the ISO 8317 or ASTM D3475 protocols.

Printing on lidding foil

Lidding foil is printed in a separate operation before blister forming, the printed foil is wound into rolls and fed into the blister line where it is heat-sealed to the forming film. Printing processes used for lidding foil in India:

• Offset printing, most common for Indian pharmaceutical lidding foil. High-quality text and graphics, accurate colour, small to medium runs economical. Most Indian pharma carton converters have offset capability for lidding foil.
• Gravure, for very high volume runs. Higher pre-press cost (cylinder engraving) but lower per-metre cost at scale. Used by large Indian generics manufacturers with very high-volume single-product runs.
• Digital printing, growing for short runs, version changes, and serialisation-adjacent applications where variable data needs to be integrated with the print.

Strip packaging is an alternative to blister packaging for single solid dosage forms. In a strip pack, tablets or capsules are individually sealed between two layers of heat-sealed foil or film-foil laminate, without a formed cavity. The tablet sits between the two flat sealing layers, the pack is not thermoformed. The patient tears the strip apart at the perforated or cut seal between doses to access individual tablets.

Strip packaging is particularly prominent in the Indian OTC (Over-The-Counter) and low-cost generic market. It is simpler and cheaper to produce than blister packaging, strip packaging machines are lower-cost and require less technical infrastructure than blister lines. However, strip packaging provides lower barrier than aluminium lidding foil blister packs and does not offer the same level of individual-dose tamper evidence. Most branded generic drugs in India use blister packaging; economy price-point OTC drugs often use strip packaging.

Strip pack materials

Cold form foil (also called alu-alu blister, cold-stamped foil, or aluminium deep-draw foil) is a blister forming material based on an aluminium foil middle layer, providing a true aluminium foil barrier on both the forming film and the lidding foil sides of the blister. Unlike PVC or PVDC forming films that are thermoformed (heated and shaped), cold form foil is formed at ambient temperature by mechanical pressure, the multi-layer laminate is stretched into the cavity shape by the forming tool without heat.

Cold form foil laminate construction

The standard cold form foil laminate is: OPA (Oriented Polyamide Nylon) 25 micron / Aluminium foil 45–60 micron / PVC 60 micron. The OPA outer layer provides the structural flexibility for cold forming without cracking. The aluminium foil middle layer provides the ultimate barrier. The PVC inner layer provides the heat-seal surface for bonding to the aluminium lidding foil.

When cold form foil is required

• Extremely moisture-sensitive drugs, hygroscopic active pharmaceutical ingredients (APIs) that would degrade within weeks under Zone IVb conditions in standard PVC/PVDC blisters
• Oxygen-sensitive drugs, the aluminium foil provides essentially zero oxygen transmission, extending the shelf life of oxidation-prone APIs
• Light-sensitive drugs, the opaque aluminium barrier provides complete light protection on both faces of the blister
• High-value biological drugs, biopharmaceuticals requiring the maximum available protection from environmental stressors
• Export to very hot and humid markets, products exported from India to Gulf, African, and Southeast Asian markets where temperatures and humidity exceed Zone IVb conditions

The secondary packaging for pharmaceutical blister packs consists of the folding carton (the printed paperboard outer box) and the package insert (the printed paper leaflet containing complete prescribing information or patient information leaflet). Both must meet the Drugs and Cosmetics Act requirements and the CDSCO (Central Drugs Standard Control Organisation) labelling guidelines for the specific product.

Pharma carton · mandatory print requirements

Every pharmaceutical folding carton sold in India must carry the following mandatory information, printed legibly and indelibly:

• Brand name and generic name (INN), the International Non-proprietary Name must appear with prominence
• Strength, e.g., "500 mg", "10 mg/5 ml"
• Dosage form, "Tablets", "Capsules", "Syrup" etc.
• Net quantity, number of tablets/capsules or volume of liquid
• Composition, each active ingredient with its quantity per unit dose
• Manufacturing Licence Number
• Batch/Lot Number, preceded by "Batch No." or "B. No." or "Lot No."
• Date of manufacture, preceded by "Mfg. Date" or "Mfd."
• Expiry date, preceded by "Exp. Date" or "Exp.", must be prominently displayed
• MRP, Maximum Retail Price inclusive of all taxes as required by DPCO (Drug Price Control Order)
• Schedule classification, "Schedule H drug, Not to be sold without prescription", "Schedule H1 drug", "Schedule X drug" etc. as applicable, printed in red on a white background
• Storage instructions, "Store below 25°C", "Protect from light and moisture" etc.
• Manufacturer's name and address, full address of the manufacturing site
• Country of origin, for imported drugs

Package insert requirements

For prescription drugs (Schedule H, H1, X), a package insert (PI) containing the full prescribing information must be enclosed with every retail unit. The PI content is regulated by CDSCO and must include: indications, dosage and administration, contraindications, warnings and precautions, drug interactions, adverse reactions, overdosage, pharmacology, and storage. PI content must be approved by CDSCO as part of the drug registration dossier, the text cannot be changed without regulatory approval.

Font size and legibility requirements

The Drugs and Cosmetics Act and CDSCO guidelines specify minimum font sizes for key information on pharmaceutical packaging. While a universal minimum is not mandated for all text, the practical standards applied by industry and accepted by CDSCO are: batch number and expiry date, minimum 2mm character height (approximately 6pt); general mandatory information, minimum 1.5mm; package insert body text, minimum 1.0mm (approximately 3pt, which is the absolute minimum for readability). For packaging intended for export to EU or US markets, the minimum font sizes required by those markets (typically 8–9pt for body text in the EU Summary of Product Characteristics format) must be met additionally.

Schedule M of the Drugs and Cosmetics Act specifies the Good Manufacturing Practice (GMP) requirements for pharmaceutical manufacturing in India, including specific requirements for packaging materials, packaging processes, and packaging quality control. Compliance with Schedule M is mandatory for all pharmaceutical manufacturers selling products in India, and the updated Schedule M (2023 revision, phasing in through 2025–2026) aligns India's GMP standards more closely with ICH Q7 and WHO GMP guidelines.

Packaging material requirements under Schedule M

• Approved vendor list, all primary packaging materials (blister forming films, lidding foils, carton board, inserts) must be sourced only from vendors on the pharmaceutical company's Approved Vendor List (AVL). Vendors must be audited and approved against defined quality criteria before supply commences.
• Certificate of Analysis (CoA), every incoming batch of primary packaging material must be supplied with a Certificate of Analysis from the manufacturer, certifying compliance with the agreed specification for all critical parameters.
• Incoming material testing, primary packaging materials must be tested against specification on incoming receipt. Dimensional checks, barrier tests (MVTR), heat-seal strength, and identity verification (IR spectroscopy for plastics) are the minimum incoming test requirements.
• Printed material verification, every batch of printed packaging material (cartons, lidding foil) must be 100% inspected for print legibility, correct content, and absence of damaged or illegible text before use. This is a 100% inspection requirement, not a statistical sample.
• Reconciliation, every batch of packaging material issued to a production batch must be fully reconciled at the end of the batch. All material used, all rejected, and all returned to stock must be accounted for. Unaccounted packaging materials are a major GMP finding.

Board specification for pharma cartons under Schedule M

Schedule M requires pharmaceutical carton board to be of food-grade quality, made from virgin fibre (no recycled content), and to have no migration of harmful substances to the drug product. This effectively mandates SBS (Solid Bleached Sulphate) board for direct drug contact applications. FBB (Folding Box Board) with recycled middle layer is generally not acceptable for pharmaceutical cartons in India, the recycled fibre middle layer has migration risk that is incompatible with pharmaceutical GMP.

Pharmaceutical serialisation is the process of assigning a unique identity to each individual saleable unit of a pharmaceutical product, typically each carton, through a unique serial number encoded in a machine-readable barcode or 2D code. The purpose is to enable track-and-trace capability throughout the pharmaceutical supply chain: from manufacture to distribution to dispensing, every pack's movement can be tracked and verified. Serialisation is the primary tool for combating counterfeit pharmaceutical products, a serious and growing problem in India and globally.

India's pharmaceutical track-and-trace requirements

India's Ministry of Health has mandated track-and-trace (T&T) for pharmaceutical products sold in India through the CDSCO's Drug Supply Chain management system. The requirements apply in phases by company size and product category:

• Large pharmaceutical companies: serialisation of all Schedule H drugs at the primary pack level, with data uploaded to the national T&T portal
• Medium and small companies: phased implementation timelines based on company turnover and product categories
• Export products: many export markets (EU, US, Saudi Arabia) have their own serialisation requirements which may be more stringent than India's domestic requirements, exporters must comply with the destination market requirements

The GS1 DataMatrix barcode for pharmaceutical serialisation

The barcode used for pharmaceutical serialisation in India and globally is the GS1 DataMatrix, a two-dimensional matrix code that encodes a defined set of data elements using GS1 Application Identifiers. The minimum required data elements for a serialised pharmaceutical pack are:

• AI (01), GTIN (Global Trade Item Number): the 14-digit product identifier registered with GS1 India
• AI (17), Expiry date in YYMMDD format
• AI (10), Batch/lot number
• AI (21), Serial number: a unique alphanumeric string that makes each individual pack uniquely identifiable globally

The DataMatrix must be at least 5×5mm in size for reliable scanning with pharmaceutical T&T scanners. It must be placed on the carton in a defined location that allows scanning in the distribution chain. Minimum ISO 15415 verification grade B is required for pharmaceutical DataMatrix codes, and many regulated markets (EU, US) require grade A.