Pharmaceutical Blister Films: PVC, PVDC, EVOH & LDPE Guide

PVC, PVDC, EVOH and LDPE in Pharmaceutical Blister Packaging

Selecting the right pharmaceutical blister packaging film is not simply a choice between PVC, PVDC, EVOH and LDPE. These polymers perform different functions inside pharmaceutical packaging structures, and they are frequently combined to achieve the required balance of thermoformability, oxygen barrier, moisture protection, sealing performance, clarity and production efficiency.

In a conventional blister package, rigid PVC may serve as the thermoformable forming web. PVDC can be coated onto PVC or incorporated into a multilayer structure to improve moisture and oxygen barrier. EVOH is primarily used as a high oxygen- and gas-barrier layer inside multilayer packaging, while LDPE can provide flexibility, moisture protection and heat-sealing functionality.

For pharmaceutical manufacturers and packaging converters, the correct material should therefore be selected according to the drug's stability data, target oxygen transmission rate (OTR), water vapor transmission rate (WVTR), cavity geometry, sealing system, storage climate, shelf-life target and destination-market requirements.

First Understand the Role of Each Material

1. PVC Film for Pharmaceutical Blister Packaging

What Is Pharmaceutical Rigid PVC Film?

Pharmaceutical rigid PVC film is one of the established thermoformable forming webs used for tablet and capsule blister packaging. During production, the PVC web is heated and formed into cavities, filled with the pharmaceutical product and then sealed with a compatible lidding material.

Its primary advantages are controlled thermoforming, optical clarity, dimensional stability and relatively economical processing. Transparent PVC also allows tablets or capsules to remain visible for product identification and inspection.

Typical Advantages of PVC Blister Film

• Good thermoforming performance for conventional blister cavities

• High product visibility when transparent grades are used

• Good rigidity and dimensional stability

• Widely established on pharmaceutical blister equipment

• Available in different thicknesses, widths, colors and roll configurations

• Practical cost-performance balance for products with moderate barrier requirements

When Is Plain PVC Appropriate?

Plain PVC is generally evaluated when the formulation is sufficiently stable under the expected storage conditions and does not require an advanced water-vapor or oxygen barrier. Typical candidates can include selected tablets, capsules, vitamins, nutraceuticals and other solid-dose products after packaging qualification.

Limitations of Plain PVC

Standard rigid PVC provides a baseline packaging barrier, but highly moisture-sensitive or oxygen-sensitive pharmaceutical products may require a stronger barrier structure such as PVC/PVDC, PVC/PE/PVDC, PVC/EVOH/LDPE, PCTFE-based film or another validated packaging system.

Wallis currently supplies pharmaceutical rigid PVC blister film in approximately 0.15–0.80 mm thickness, with customized width, color, surface finish and roll configuration available according to the approved packaging specification.

2. PVDC-Coated Film for Higher Moisture and Oxygen Barrier

What Does PVDC Do in Pharmaceutical Packaging?

PVDC, or polyvinylidene chloride, is commonly used as a barrier coating or component in pharmaceutical blister films. A typical construction uses rigid PVC as the thermoformable base while PVDC provides additional protection against water-vapor and oxygen transmission.

Unlike plain PVC, the barrier performance of PVDC-based film can be adjusted through the PVDC coating weight, coating formulation and overall multilayer structure. This allows packaging engineers to match different barrier levels with different drug-stability requirements.

Typical Advantages of PVC/PVDC Structures

• Higher moisture barrier than standard mono PVC

• Improved oxygen and gas barrier

• Transparent blister configurations remain possible

• Multiple barrier levels can be engineered through coating weight and structure

• Useful for moisture-sensitive and oxygen-sensitive formulations

• Can be designed for conventional thermoforming equipment

Do Not Compare PVDC Barrier by Polymer Name Alone

Statements such as “PVDC is ten times better than PVC” are not sufficiently precise for pharmaceutical packaging selection. Barrier values depend on coating weight, base film, total thickness, temperature, relative humidity, forming depth and test method.

Buyers should therefore request measurable WVTR and OTR values together with the applicable test conditions rather than relying only on terms such as standard barrier, high barrier or ultra-high barrier.

3. EVOH as an Oxygen-Barrier Layer in Pharmaceutical Packaging

What Is EVOH?

EVOH, or ethylene vinyl alcohol copolymer, is a high-performance polymer primarily selected for its excellent resistance to oxygen and other gas transmission. In pharmaceutical packaging it is usually used as a relatively thin functional layer inside a multilayer structure rather than as a standalone rigid blister forming film.

Structures such as PVC/EVOH/LDPE combine different polymers because a single material does not normally provide optimum rigidity, gas barrier, moisture barrier and heat sealing at the same time.

EVOH Is Primarily an Oxygen Barrier

EVOH can substantially reduce oxygen transmission and is therefore relevant for oxygen-sensitive pharmaceuticals, diagnostics, nutraceuticals and healthcare formulations where oxidative degradation is a packaging concern.

Why Humidity Matters for EVOH

EVOH is sensitive to moisture. Its oxygen-barrier performance changes as humidity increases, which is why it is normally encapsulated between protective polymer layers instead of being exposed directly as the primary moisture-barrier surface.

Surrounding layers such as LDPE or other polyolefins can help reduce moisture exposure to the EVOH layer, while the entire structure must be designed to achieve the required final OTR and WVTR.

Is EVOH Automatically a More Sustainable Choice?

Not automatically. EVOH is chlorine-free and can be incorporated into specially engineered packaging structures designed for improved recyclability, but the environmental performance of a finished pharmaceutical package depends on the complete material structure, layer percentages, regional recycling infrastructure, package weight and product-protection performance.

Buyers should therefore avoid treating the presence of EVOH alone as proof that a multilayer package is recyclable or environmentally preferable.

Wallis supplies PVC/EVOH/LDPE high-barrier packaging sheet in customized multilayer configurations for pharmaceutical, medical, diagnostic and healthcare packaging projects.

4. LDPE as a Sealant and Protective Layer

What Role Does LDPE Play?

LDPE, or low-density polyethylene, is a flexible polyolefin widely valued for heat-sealing performance, flexibility and moisture resistance. In many pharmaceutical multilayer structures it functions as a sealant, inner layer or protective layer rather than as the primary rigid blister forming web.

In a PVC/EVOH/LDPE structure, PVC can provide rigidity and thermoforming support, EVOH contributes oxygen barrier, and LDPE can provide sealing performance while also helping shield the EVOH layer from moisture exposure.

Typical Benefits of LDPE

• Good heat-sealing capability

• Flexible layer construction

• Useful water-vapor resistance within an engineered laminate

• Can protect moisture-sensitive internal barrier layers

• Useful in multilayer pharmaceutical and medical packaging structures

Seal Strength Depends on the Complete System

The presence of LDPE does not by itself guarantee a suitable pharmaceutical seal. Seal initiation temperature, dwell time, pressure, LDPE grade, thickness and the mating lidding material all affect final seal strength and package integrity.

The completed package should therefore be evaluated for seal strength, channels, leakage and integrity under the intended manufacturing, transportation and storage conditions.

PVC vs. PVDC vs. EVOH vs. LDPE: Pharmaceutical Packaging Comparison

A star-rating comparison can oversimplify pharmaceutical packaging performance because these four materials serve different roles. The following table provides a more useful engineering comparison.

OTR and WVTR: The Two Barrier Values Buyers Should Specify

What Is OTR?

Oxygen Transmission Rate (OTR) measures how much oxygen passes through a packaging material under defined test conditions. OTR is particularly important for pharmaceutical products that can undergo oxidative degradation.

What Is WVTR?

Water Vapor Transmission Rate (WVTR) measures water-vapor permeation through a packaging structure under defined conditions. WVTR is particularly important for hygroscopic tablets, capsules and formulations whose stability changes with moisture exposure.

Why Test Conditions Must Be Included

Barrier values can change with temperature, relative humidity, thickness and test method. Two supplier specifications should therefore not be compared unless the reported conditions are equivalent.

An RFQ should ideally state the target OTR or WVTR together with temperature, relative humidity and applicable test method.

Flat-Film Barrier Is Not the Same as Formed-Blister Barrier

Pharmaceutical films are stretched during thermoforming. As the film enters a deep cavity, the material becomes thinner at cavity walls and corners. This can change both mechanical strength and barrier performance compared with the original flat-film specification.

For critical products, packaging engineers should therefore evaluate the barrier and integrity of the finished formed blister, not only the OTR or WVTR of the original roll material.

Forming depth, draw ratio, heating profile, cavity shape and layer distribution should all be considered during qualification.

Lidding Foil and Heat-Seal Compatibility Matter

A pharmaceutical blister is a complete packaging system consisting of the forming web, pharmaceutical product, lidding material and seal. Selecting a suitable bottom film without confirming lidding compatibility can result in poor seal strength or package-integrity failures.

Conventional PVC blisters commonly use aluminum lidding foil with a heat-seal lacquer designed to bond to PVC. Multilayer structures containing PE or LDPE may require a different sealing configuration. The buyer should therefore provide the current lidding specification when qualifying a replacement film.

How to Choose the Right Pharmaceutical Blister Structure

1. Start With Drug Stability Requirements

Determine whether the packaged formulation is sensitive primarily to moisture, oxygen, light, temperature or a combination of these conditions. The package should be selected to protect the product throughout its intended shelf life.

2. Define Target OTR and WVTR

Convert the stability requirement into measurable packaging targets wherever possible. Avoid specifications that only say “high barrier” without defining the expected oxygen and water-vapor transmission performance.

3. Consider the Destination Climate

Temperature and humidity during storage and distribution can substantially influence package performance. Products shipped to hot and humid climates may require a different barrier specification from products distributed under less demanding conditions.

4. Provide the Blister Cavity Geometry

Tablet dimensions, capsule size, cavity depth and draw ratio influence material thinning during thermoforming. The nominal thickness of the flat film should therefore be selected together with the finished cavity design.

5. Confirm the Blister Machine

Machine heating zones, forming method, line speed, web width, sealing system and registration requirements can influence material selection. Buyers replacing an existing supplier should provide the current film specification and machine model whenever possible.

6. Confirm Lidding and Seal Requirements

Supply the lidding foil or sealing-web specification, required seal strength and sealing conditions so the complete forming-web and lidding combination can be evaluated.

7. Evaluate the Finished Package

Material qualification should include the actual formed and sealed pack under relevant production, transportation, storage and stability conditions rather than relying solely on a supplier's flat-film technical data.

Which Structure Fits Different Barrier Requirements?

Pharmaceutical Packaging Compliance and Qualification

A material described as “pharmaceutical grade” should not be treated as proof that every finished package is automatically suitable for every medicine or market.

Pharmaceutical companies should evaluate the suitability of the complete packaging system according to the intended drug product, contact conditions, barrier requirements, compatibility, safety, protection, manufacturing process and applicable destination-market regulatory requirements.

Buyers should request relevant specifications, test reports and regulatory documentation for the exact material grade being qualified and complete their own package-development and stability-validation process.

Sustainability: Avoid Simple Material Rankings

Sustainability cannot be accurately represented by assigning PVC, PVDC, EVOH and LDPE a simple number of “eco-friendly stars.” A pharmaceutical package must first provide the barrier and integrity needed to protect the medicine throughout its intended shelf life.

Relevant sustainability factors can include total material weight, polymer composition, halogen content, recyclability within the intended regional stream, manufacturing efficiency, blister footprint, secondary packaging requirements and the risk of product loss caused by insufficient barrier protection.

The pharmaceutical packaging industry is developing mono-material and polyolefin-based structures, including selected designs that use EVOH as a thin oxygen-barrier component. However, recyclability claims should be verified for the complete finished package and the intended waste-management system.

What Information Should Buyers Include in a Pharmaceutical Film RFQ?

• Packaging application: tablet blister, capsule blister, nutraceutical, diagnostic, medical or another format.

• Existing structure: PVC, PVC/PVDC, PVC/PE/PVDC, PVC/EVOH/LDPE or current supplier TDS.

• Total thickness: required film or sheet gauge.

• Layer structure: coating weight or layer ratio where already defined.

• Target OTR: including temperature, RH and test method.

• Target WVTR: including temperature, RH and test method.

• Blister machine: manufacturer, model and line speed where relevant.

• Cavity dimensions: tablet/capsule size, cavity depth and drawing.

• Lidding material: aluminum foil or other sealing-web specification.

• Roll specification: width, core diameter, roll diameter and winding requirement.

• Color and clarity: clear, tinted, opaque or customized color.

• Storage climate: expected temperature and humidity conditions.

• Destination market: country or region and required documentation.

• Quantity: sample, validation quantity and expected commercial demand.

Why Work With Wallis for Pharmaceutical Packaging Films?

Multiple Pharmaceutical Packaging Structures

Wallis supplies multiple rigid and multilayer pharmaceutical packaging materials, including plain PVC blister film, PVDC-based high-barrier structures and PVC/EVOH/LDPE multilayer sheet for different barrier and converting requirements.

Custom Thickness, Width and Roll Configuration

Material thickness, width, color, opacity, roll dimensions, core size and multilayer configuration can be discussed according to the customer's blister machine and approved packaging specification.

Barrier Targets Can Be Defined by OTR and WVTR

For high-barrier projects, buyers can provide their target oxygen and water-vapor transmission requirements instead of relying only on generic descriptions such as medium barrier or high barrier.

Sample Qualification Before Commercial Production

Pharmaceutical packaging materials should be evaluated on the intended production equipment and qualified with the actual product, forming conditions, lidding system and storage requirements before commercial use.

Frequently Asked Questions About PVC, PVDC, EVOH and LDPE Pharmaceutical Films

What is the most common role of PVC in pharmaceutical blister packaging?

Rigid PVC is commonly used as the thermoformable forming web that creates the tablet or capsule cavity. It offers a useful combination of clarity, rigidity, forming performance and cost efficiency.

What is the difference between PVC and PVC/PVDC blister film?

Plain PVC primarily provides thermoforming and structural support. A PVDC-coated or PVDC-containing structure adds greater resistance to water-vapor and oxygen transmission. The exact barrier improvement depends on coating weight and total structure.

Is PVDC always better than PVC?

No. PVDC provides additional barrier performance but also creates a more complex and usually higher-cost structure. Plain PVC may be sufficient when stability studies show that the drug does not need the additional barrier.

What is the main advantage of EVOH in pharmaceutical packaging?

EVOH is primarily selected for its excellent oxygen and gas barrier. It is normally incorporated as an internal layer in a multilayer packaging structure.

Does EVOH provide a high moisture barrier?

Moisture barrier is not EVOH's primary function. EVOH is humidity-sensitive, so it is commonly protected by surrounding polymer layers. The total WVTR of the finished multilayer package should be evaluated separately.

What does LDPE do in a PVC/EVOH/LDPE structure?

LDPE can provide heat-sealing functionality, flexibility and moisture protection while helping isolate the EVOH oxygen-barrier layer from humidity.

Is LDPE normally used as a rigid tablet blister forming film?

Not normally. LDPE is more commonly used as a flexible sealant or functional layer in a multilayer structure. Rigid PVC or another thermoformable rigid polymer usually provides the structural blister cavity.

What is OTR in pharmaceutical packaging?

OTR means Oxygen Transmission Rate. It measures oxygen permeation through the packaging material under specified conditions and is an important parameter for oxygen-sensitive products.

What is WVTR in blister packaging?

WVTR means Water Vapor Transmission Rate. It measures water-vapor permeation through the packaging material under specified conditions and is particularly important for moisture-sensitive products.

Can I compare OTR and WVTR from two suppliers directly?

Only when the values were measured using comparable material thicknesses, temperatures, relative humidities and test methods. Barrier numbers reported under different conditions should not be treated as directly equivalent.

Does thermoforming change blister barrier performance?

Yes. Thermoforming stretches the material and can reduce the thickness of individual layers at cavity walls and corners. Critical products should be evaluated using the actual formed package.

Which film is best for highly moisture-sensitive pharmaceuticals?

There is no universal answer. High-PVDC, PCTFE-based or cold-form aluminum structures may be evaluated when very low water-vapor transmission is required. The final decision should be based on drug-stability and packaging-validation data.

Which structure is suitable for oxygen-sensitive products?

EVOH-containing multilayer structures can be strong candidates where oxygen protection is a primary requirement. PVDC and other high-barrier structures may also be considered depending on moisture, forming and regulatory requirements.

Is EVOH pharmaceutical packaging recyclable?

Recyclability depends on the complete multilayer structure, EVOH percentage, other polymers, lidding material and the local recycling stream. The presence of EVOH alone does not prove that a finished pharmaceutical package is recyclable.

Should pharmaceutical blister film be tested before a commercial order?

Yes. Buyers should evaluate forming, sealing, printability where relevant, dimensional stability, finished-pack integrity and required barrier performance on the intended packaging equipment before commercial qualification.

Choose the Packaging Structure From the Drug Requirement, Not the Polymer Name

PVC, PVDC, EVOH and LDPE should not be viewed simply as four competing pharmaceutical blister films. Each polymer performs a different function, and multilayer packaging works by combining those functions into a structure matched to the pharmaceutical product.

PVC provides rigidity and thermoforming. PVDC improves moisture and oxygen barrier. EVOH provides strong oxygen and gas protection but normally requires moisture-protective surrounding layers. LDPE provides sealing and contributes moisture protection within a multilayer design.

For a new pharmaceutical packaging project, provide Wallis with your current structure, target OTR and WVTR, film thickness, cavity geometry, blister-machine information, lidding specification, destination climate and required quantity so the appropriate material can be evaluated for sample qualification.