Pharmaceutical packaging plays a critical role in the safe storage and delivery of medicines to patients – from jars and bottles to key accessories like bottle closures and caps. These accessories can be used to secure medical products and provide a child-proof mechanism, as well as support the intuitive and accurate dispensing of dosages.
But which caps and closures are most suited to different pharmaceutical containers and medicines?
In this guide, Origin explores the different types of bottle closures and their unique benefits and use cases, as well as the different materials commonly used in caps and closures.
An Overview of Bottle Closures: Understanding Different Types and Their Functions
There are several types of bottle closures, with unique features and benefits that make them suited to a particular set of purposes and products.
Below is an overview of some of the most common bottle closures and how they prove useful in a range of packaging solutions:
- Screw Caps: Provide a simple and secure seal for bottles, and are primarily used in beverages, personal care items and pharmaceuticals like creams and lotions.
- Cork Closures: Provide an airtight seal that prevents leaks, while allowing oxygen transmission.
- Dispensing Closures: Include sprays, pumps and droppers. Often used in the pharmaceutical industry.
- Flip-Top Closures: Easy to open and close, generally used for personal care products like shampoo.
- Child-Resistant Closures: Used in the pharmaceutical industry to prevent accidental ingestion by children.
- Tamper-Evident Closures: Provide a clear indication that a bottle has been tampered with, preventing any risks associated with falsified medicines or worse.
A Guide to Screw Caps
Screw caps offer many key advantages, including being simple to open and providing an airtight seal, protecting contents inside from oxygen and increasing product shelf life.
These closures also prevent leaks, which is essential for packaging potentially harmful pharmaceutical products. Screw caps are also commonly made from polypropylene and polyethylene which makes them highly recyclable and reusable.
They are also extremely cost-effective to produce in bulk and can be used for a wide range of products.
Screw Cap Variations
- Threaded Skirt Screw Caps: Threaded skirt screw caps match the bottle’s seal lining, providing a flush and secure tamper-evident seal for products.
- Dispensing Screw Caps: These types of screw caps include elements of flip caps in their design with a flip-top or push-down lid that controls the dispensing of the product.
Exploring Cork Closures
Cork closures provide an aesthetic elegance to packaging that is generally more suited to the food and beverages sector, where their porous nature also helps the ageing of wines.
Cork is also natural and sustainable, which is better for the environment and reduces waste compared with some alternative materials.
Despite allowing oxygen to permeate, cork also has a natural elasticity which means it can contract and expand to fit any bottleneck and provide an air-tight seal that stops liquid leaking.
Cork Variations
- Natural Cork: This type of cork is commonly made from bark and is sustainable and reusable.
- Agglomerated Cork: A type of cork closure that is constructed from glued granules, providing a rigid structure.
Understanding Dispensing Closures
Dispensing closures come in three distinct types: pumps, sprays and droppers. They are generally used for pharmaceutical products that require direct application, such as disinfectant sprays or drops for eyes or ears.
The pump, spray or dropping nozzle also provides controlled product application, which is perfect for pharmaceutical goods where accurate dosages need to be dispensed.
Dispensing closures also prevent hygiene issues such as cross-contamination, as they have limited contact with skin.
Variations of Dispenser Closures
- Droppers: Droppers consist of lids attached to a small pipette that allows for the application of stored pharmaceuticals drop by drop.
- Sprayers: A type of dispenser bottle cap that applies the stored product in a mist form to cover a wide surface area.
- Pumps: Pump bottle caps are designed to dispense liquid by applying pressure to the pump and are often used for medical hand sanitiser and topical creams.
The Convenience of Flip-Top Closures
The biggest selling point of flip-top closures is how easy they are to open, making them ideal for quick-apply pharmaceuticals like creams and ointments. Flip-top closures can also be opened easily with one hand to help with dispensing.
Flip-top closures are highly customizable and cost-effective while protecting contents from contaminants.
Flip-top Closure Variations
- Push Button Flip Closure: This variation of flip closure includes the addition of a button that must be pressed before the flip cap is released. This adds an extra level of security to the product and further avoids spills.
- Locking Flip-Top Closure: For greater security and child resistance, a locking mechanism ensures the flip-top cap doesn’t accidentally open.
Child Resistant and Tamper Evident Closures
Consumer peace of mind is important, especially when it comes to the handling of pharmaceutical products – many of which can be toxic or hazardous when handled by unwanted users.
This is why tamper-evident and child-proof bottle closures are critical, allowing consumers to clearly see if a product has been opened and preventing accidental access to children.
Some common types of tamper-evident packaging are:
- Continuous Thread Closure: This type of bottle closure links the closure to a band around the neck of the bottle through a continuous line of plastic threads. Not only does this secure the container from outside influence but, if the threads are broken, it is clear to the patient that the container has been tampered with.
- Tamper Evident Shrink Bands/Wraps: These are plastic bands or wraps that are applied around the closure of a container, such as a bottle or jar. They must be broken or cut to access the contents, leaving clear signs of tampering.
Child-resistant closures typically include complex locking mechanisms that prevent children easy access to children.
These are specialized caps or closures that require a specific combination of actions, such as squeezing, pushing, or turning, to open the container. They are designed to be difficult for young children to open while being easily accessed by adults.
Types of Materials used in Bottle Closures
Here, Origin explores the two key materials used in pharmaceutical bottle closures – metal and plastic – and their unique benefits…
Understanding Metal Closures
Metal closures are the most durable of any bottle caps and are less prone to breaking or deformation – making them ideal for long-term storage or unique and specialist closures where product integrity is critical.
They are commonly used in specialist pharmaceutical packaging, such as bottle closures for parenteral medicines administered through injection or infusion.
Metal closures are also highly reusable and recyclable compared with some plastics.
Variations of Metal Closures
- Screw Caps: Metal closures can come in screw cap varieties to secure contents while providing an intuitive method of opening.
- Flip-Top Caps: Metal closures can come in flip-top variants to provide an easier way to open and apply products while remaining a durable defence against the elements.
The Use of Plastic in Bottle Closures
Plastic bottle closures are some of the most widely used due to their low density and ease of manufacture – making them easy to mass-produce while remaining cost-effective. They are also lightweight to save money in bulk shipping costs.
Plastic is also extremely versatile, creating a variety of shapes. Polypropylene and polyethylene are among the most popular and durable plastics that can be used to create an air-tight seal, preventing any stored products from leaking.
Most plastic bottle caps are also designed to be highly reusable and recyclable, making them ideal for sustainable businesses.
Variations of Plastic Bottle Closures
- Polypropylene: Polypropylene is a type of plastic that can withstand the sterilization process, making it perfect for use in the pharmaceutical industry.
- Polyethylene: Polyethylene is highly chemical resistant, making it perfect for products where chemical erosion and leaking are risks.
Choosing the Right Closure for a Pharmaceutical Product
When choosing the right type of closure for a pharmaceutical product, many factors need to be considered to deliver medicine safely and intuitively to patients:
- Product Compatibility: Consider the physical characteristics of the product that needs to be stored. Some products may require specific enclosure requirements, for example, a vial containing corrosive liquid may require a cap that is chemical-resistant to avoid leaking or contamination.
- Regulatory Compliance: The packaging must also comply with regional or industry regulations. For example, ISO 8317 regulations require reclosable packages to be resistant to opening by children.
- Product Protection: Consider the product. It may require additional protection from UV rays, or the packaging must provide an air-tight seal. It’s these essential considerations that maintain integrity and improve the shelf life of pharmaceutical products.
- Cost Considerations: Essential to the cost-effective shipping of pharmaceutical goods. The lighter a package, the less it costs to transport. Polyethylene and polypropylene are examples of plastics that are highly cost-efficient to manufacture.
Emerging Trends in Bottle Closure Design
Pharma packaging design is a field that is always innovating, as manufacturers and healthcare companies look to find new ways to securely store and intuitively and accurately dispense medicines.
However, there are two key areas set to impact the future of bottle closure design more than any other:
- Sustainability: Reducing waste and re-using energy is a key demand of modern eco-conscious consumers. Manufacturers will continue to find new ways to develop packaging made from sustainable materials without compromising on the core functionality of medical products.
- Bespoke packaging: With compliance and sustainability only becoming more critical, many businesses will look to develop bespoke solutions, instead of compromising on core features with off-the-shelf products. This may include sustainability or unique features like child-proof locking mechanisms and UV-protected bottle caps.
Frequently Asked Questions (FAQs)
What Is Continuous Thread Closure?
Continuous thread closure, also known as continuous thread cap, is a type of bottle closure commonly used for sealing bottles, jars or containers. The threads on the inside of the cap are attached to the threads on the container neck, locking them in place. To open the product, those threads must be pried apart. Continuous thread closure is one of the best tamper-evident closure designs, as it gives a clear indication of when the bottle has been opened after sealing.
