Syringes and needles are used for both injecting medication and withdrawing fluids. They are among the most frequently used medical supplies in healthcare today. While they appear simple needles have undergone significant innovation since their invention. Such innovations have helped improve needle performance and patient comfort. One of the key innovations is needle coatings. Hydrophilic coatings for needles create a thin, lubricious (slippery when wet) layer on the surface of the needle. The coatings help ensure smooth insertion into the body. They also enhance patient comfort by reducing tissue damage.
In this informative guide we introduce hydrophilic needle coatings. We will discuss the benefits of hydrophilic coatings, specifically how they help improve the performance and safety of medical needles. At the end of the article we compare hydrophilic and hydrophobic coating for needles.
You may also be interested in our in-depth guide covering Hydrophilic Coatings for Medical Devices, where we discuss other uses of these coatings.
The Importance of Needles and Syringes in Healthcare
Needles and syringes are required for a wide range of medical procedures. They are used for routine medical procedures, such as delivering antibiotics and drawing blood. They are also used for more complex procedures, such as during a biopsy for withdrawing tissue samples. As a result, needles and syringes are among the most frequently used medical supplies in the healthcare industry. And as a result, their performance and safety, while sometimes taken for granted are extremely important.
What is a syringe? What are they Used for?
A syringe is made up of two main parts: a plastic barrel and a steel needle. As mentioned above, these supplies play a critical role in nearly every medical procedure.
Such an indispensable medical instrument serves the following purposes (including but not limited to):
- Injecting medications
- Vaccinations
- Drawing blood or other fluids
- Fluid delivery
Their importance and ease of use has made them one of the most widely used medical supplies today. And the use of surface modifications, including hydrophilic needle coatings, have made them more precise, safer, and less painful.
Introduction to Hydrophilic Needle Coatings & How They Work
Hydrophilic coatings are applied to the surface of needles. These surface treatment coatings help make the needles more biocompatible, precise, and safer to use.
What is a hydrophilic coating, and why are they used to coat needles?
The term “hydro” means water, and “philic” means affinity or love-for. As you can guess, hydrophilic coatings modify the coated surface and make it water-loving. As a result, water molecules are attracted to the surface. This creates a “slippery-when-wet” surface that has excellent lubricity (low to no friction). The result is reduced friction of the needle and improved insertion.
The main goal of hydrophilic coated needles is to make medical procedures safer and improve comfort for patients.
Hydrophilic medical coatings are formulated with polymers, such as poly(acrylic acid), polyvinyl alcohol (PVA), and polyethylene glycol (PEG). Polymer-based hydrophilic coatings improve navigation and ensure biocompatibility over extended periods.
Benefits of Hydrophilic Coated Needles
Needles are typically made from stainless steel. The outer surface of the needle is coated with hydrophilic formulations.
There are a number of benefits to applying hydrophilic coatings on needles. These include the following:
- Smoother Insertion: Hydrophilic coatings are “slippery-when-wet” surface modifications. The lubricity of the coating is drastically increased in the presence of body fluids. This property helps achieve smooth movement and insertion in the body. Surgeons or clinicians can get better feedback for accurate insertion and placement by feeling subtle changes in tissue layers.
- Improved Patient Comfort: These coatings are used to decrease the trauma caused by the irritation between the needle and body tissues. They absorb water to create a highly lubricious thin film that reduces resistance as the needle passes through the skin, tissues, etc..
- Enhanced Biocompatibility: Needles should be safe and biocompatible. Adverse reactions such as inflammation or infection are common when needles are inserted into the skin. Hydromer®, Inc. hydrophilic needle coatings are biocompatible.
- Patient Safety: As per the NIH reports, millions of needlestick injuries occur annually. Hydrophilic coatings for needles can help prevent the “sticking” of blood or tissue fluids on the surface of the needles. This aids in ultimately reducing the risk of bloodborne infections.
- Improved Precision: Smooth and predictable insertion is critical in using needles to deliver drugs. Hydrophilic coatings reduce insertion force and help the needle follow a straight path. This is particularly helpful in medical procedures like biopsies and spinal anesthesia.
Benefits of Applying Hydrophilic Coatings on Syringes
In some applications, syringes are also coated with hydrophilic coatings. They are applied particularly to the internal surface of a pre-filled syringe barrel or hollow tube that holds the liquid.
The benefits of using hydrophilic coatings inside the syringe barrel are:
- Reduced friction between plunger and barrel
- Enhanced control and consistency during drug delivery
- Preventing sticking of drugs to the inside of the barrel and improves fluid flow
- Avoiding the risk of contamination, especially in the case of protein-sensitive drugs
- Improved biocompatibility
Manufacturers mainly use silicon oil in the inner part of the syringe barrel. It promotes smooth plunger movements and accurate drug delivery. However, silicon oil can interact negatively with sensitive drugs. Advanced hydrophilic syringe coating formulations can be used in place of silicon oil to prevent this problem. These coatings need to be robust enough to withstand mechanical stress imposed by the plunger.
Comparison: Hydrophilic vs. Hydrophobic Needle Coatings
Hydrophobic coatings are an alternative to hydrophilic needle coatings. Both are used to improve the performance, comfort, and safety of medical instruments. However, hydrophilic coatings are most commonly used in the case of medical devices that are inserted into the body during treatments, such as needles.
The right choice between hydrophilic and hydrophobic coating depends upon the application and desired outcomes.
Here is a summary of how each type of coating works:
- Hydrophobic needle coatings repel water molecules. They are used for applications where the user wishes to keep the fluids away from the needle. By preventing fluid buildup on the needle surface, it ensures cleanliness and reduces the risk of contamination.
- On the other hand, hydrophilic coatings attract water molecules and form a lubricious surface. They are used across a wide range of medical applications, including needles. Hydromer® medical coatings promote ease of insertion, reduce trauma, and help avoid tissue buildup. These properties are important with devices such as catheters, guidewires, and injection needles that are inserted inside the body.
You can read more about the differences and uses of Hydrophilic vs Hydrophobic Coatings in our article on the topic.
Conclusion: Hydromer Hydrophilic Coatings for Needles and Syringes
Around 16 billion injections are given to people annually around the world. These mainly include vaccination, immunization, and medication. Needles are one of the most highly used medical supplies in the healthcare industry. As such, improving their performance and comfort is extremely important. Hydrophilic coatings help accomplish this goal.
At Hydromer, Inc. we have 40+ years of experience manufacturing and supplying custom hydrophilic medical coatings. Our company is focused on helping medical device manufacturers improve the performance and safety of their products.
Our hydrophilic coatings can be customized to meet your specific product requirements. But what sets us apart is the wide range of support services we offer our customers. You will get more than just a medical coatings supplier. Our capabilities span from contract R&D and regulatory consulting to contract coating and technology transfer. Contact us to learn more about our extensive range of services:
- Research and Development (R&D) services
- Contract coating services
- Supply of Leading Edge Custom Coating Formulations Worldwide
- Specialized Analytical Testing
- Custom Machine Building
- Turn-key Operations
- Technology Transfer Services
- Technical consulting and support services
For quicker support, you can also contact us directly at:
Phone: +1 704-490-4031
Email: in**@******er.com
