Pharma Packaging 101: Intro to Glass Vials

We often take the containers that hold critical vaccines and drug therapies for granted. While a typical pharmaceutical glass vial may just seem like a simple cylindrical container, it is carefully and intentionally designed to deliver lifesaving medicines to patients in need with reliability and efficiency. 

Corning Pharmaceutical Technologies offers pharmaceutical packaging solutions that aim to enhance the storage and delivery of drug products, increase fill-finish efficiency, improve quality, and reduce Scope 3 emissions and material waste. But even in its simplest base form, a vial is an intricate pharmaceutical container. 

There are many details for pharmaceutical companies to consider when selecting the right package to protect, store, and deliver their drug products. This article will explore these intricacies through Corning’s expert-driven product offerings, from glass composition to external coating, and more.

The currently used international standards for converted and molded vials were first published in 1989 and have been gradually revised over time. There are two main vial formats: molded vials, which are identified by the letter H and made by injecting molten glass into a mold, and tubular vials, identified by the letter R and converted from uniform, long glass tubes. Corning exclusively manufactures tubular vials converted from its own pharmaceutical glass tubing. In fact, Corning Pharmaceutical Glass is the second largest tubing manufacturer globally.

ISO 8362-1 and ISO 8362-4 provide specifications for converted tubular and molded glass vials, respectively. Both format types cover a broad range of fill volumes, but converted tubular vials are generally preferred for smaller fill volumes due to uniform wall-thickness and better heat transfer for ideal lyophilization, and molded vials are preferred for larger fill volumes because it’s more cost-effective and typically offers a stronger chemical resistance.

Tubular pharmaceutical vials for injectable medicines are typically made from Type 1 borosilicate glass, which can come in multiple tubing formats. 51 expansion borosilicate glass tubing is the most common although 33 expansion borosilicate glass is also used (most commonly in the North American market). The glass is designed to be a long-term storage solution for pharmaceuticals with the unique ability to stay chemically inert, while still maintaining the integrity and stability of pharmaceutical preparations. Corning manufactures both 51 and 33 tubing in compliance with international pharmacopeia standards. 

Borosilicate amber glass comes into play when ultraviolet light protection is required for sensitive pharma applications. The addition of iron and titania agents to the glass composition allows the final container to block UV. Corning manufactures 51 expansion borosilicate amber glass tubing that meets international pharmacopeia standards for both chemical durability and light transmission. 

To further strengthen the pharma container and protect the valuable drugs within, Corning developed a new composition of glass, innovated beyond the traditional borosilicate. Corning’s boron free, aluminosilicate clear glass was specifically created to be the base material for Corning^® Valor^® glass vials. The glass is designed to be chemically strengthened after vial conversion. The aluminosilicate vials are subjected to a potassium nitrate bath in a process that exchanges sodium ions in the glass surface with potassium ions. The result? Vials with superior strength.

Valor glass meets the surface hydrolytic resistance performance requirements for Type I glass packaging according to USP <660> and EP (3.2.1). Valor glass vials also exhibit equivalent or better extractables and leachables performance compared to traditional borosilicate vials.

When placing a vial on a flat surface, the bottom refers to the concave face that does not directly contact the surface. The maximum distance between the vial’s bottom and the flat surface, known as the push-up, is specified based on the size of the vial. 

The footprint is the part of the vial that does contact the flat surface it sits on. The integrity of a vial’s footprint is essential for the product’s performance in production. If the footprint isn’t uniform the vial can become physically unstable which can increase the likelihood of tip overs and false rejects on the manufacturing line. 

The heel is the transitional corner between the footprint and the body of the vial. The radius of the heel can impact the mechanical reliability and machinability of the vial. For example, a smaller radius with a sharp-cornered heel can make a vial more prone to tipping over on the filling line, causing potential cracks and breaks. 

The cylindrical mid-section is known as the body of the vial, which should be consistent in diameter to streamline handling on fill-finish lines and inspection equipment. The body of converted tubular vials matches the dimensions of the tubing used.  

The shoulder is the section between the body and the neck of the vial. Improper forming of the shoulder might lead to defects that impact machinability. Consistent minor flaring of the shoulder region within a large population of vials can cause damage around the upper circumference of the vial due to glass-on-glass contact in filling lines. 

The neck of the vial is the narrow piece between the body and the flange. The dimensions and form of the inner neck are important to ensure consistent stopper insertion and to minimize the likelihood of stopper pop up. The external geometry of the neck is also critical both for handling and consistent performance during the capping process. 

The flange of the vial, which is also sometimes referred to as the crown or finish, is one of the most critical aspects. The top of the flange interacts with a compressed elastomer stopper to form what is called the “land-seal” which is primarily responsible for maintaining the sterility of the drug product, also referred to as container closure integrity (CCI).

The final part of the vial is known as a blowback, which is only sometimes included in a typical vial to prevent stopper pop up and facilitate the sealing between the stopper and the vial. The European style blowback is a protrusion that creates an undercut while the American style blowback is a groove. 

Beyond the chemical composition of the glass and the detailed design of the vial, there are a few other enhancements that can be made to these containers to improve the experience of the pharmaceutical manufacturer.

Conventional glass vials typically have a high coefficient of friction (COF), which can reduce vial flow on pharmaceutical filling lines and lead to interventions, vial jams, tip overs, and glass breakage. These issues create disruptions and inefficiencies, increasing drug filling manufacturing costs. There are several ways that pharma companies can address these issues, including external coatings that further protect and enhance the containers.

Valor vials, along with Corning Velocity^® and Viridian^® vials – both drop-in solutions made of Type I borosilicate glass – are enhanced with a proprietary external low COF coating designed to improve quality and maximize productivity. In fact, the coating offers 20-50% improvement in filling line efficiency and reduces the likelihood of damage that can lead to cracks, breaks and cosmetic defects.

Before vials are placed on a drug manufacturer’s filling line, they need to be thoroughly washed, depyrogenated, and sterilized to ensure a quality product for the end-user. While most pharma companies have the equipment to take these steps as part of their manufacturing processes, there’s a vial solution to further streamline operations and protect the end-product from contamination. 

Ready-to-use (RTU) vials come washed, depyrogenated, and pre-sterilized in industry standard secondary packaging. As the name suggests, RTU vials are ready to go directly to the filling line, which not only simplifies the implementation process, but lowers the risk of contamination by limiting the need for human interaction. All of Corning’s vial offerings are available in RTU format. 

As industry regulations, such as Annex 1, continue to tighten, concerns around contamination control and sterility are increasingly critical. Pharma stakeholders are working together at every step of the process to optimize product safety and quality, utilizing automation and packaging options that protect the drug, and more importantly, the patient. Corning’s vial coating and format options are innovated with these concerns in mind. 

Today, in the face of the world climate crisis, pharmaceutical companies also face the challenge of reducing their environmental footprint. While there are some unavoidable environmental impacts of delivering medicine to patients on a large scale, many of the industry’s effects on the environment can be reduced, eliminated, or offset. They can begin by examining their processes across the entire value chain, seeking greener sources of materials and energy, and partnering with vendors to find innovative ways to save resources. In 2023, the leaders of seven global pharmaceutical companies signed an open letter, calling on suppliers to join them in greening and decarbonizing healthcare supply chains.  

Corning’s Viridian vials offer a unique advantage that supports these sustainability goals: they are made with 20% less glass material, enabling up to a 30% reduction in cradle to gate Scope 3 emissions. All while meeting the same critical dimensional criteria and quality attributes discussed above. Thanks to the external coating, they offer the same quality and performance benefits in a more environmentally friendly package.  

Pharmaceutical glass vials serve a very important role: to protect, store, and deliver lifesaving drugs and vaccines. That’s why a great deal of care goes into their composition, design, and features. Corning’s experts understand how every detail of a glass vial can impact the pharmaceutical company filling it, the medicine it contains, and the patient who eventually receives it. 

Visit Corning’s pharmaceutical technologies webpage to learn more about our pharmaceutical container offerings or contact us for a consultation.