Medical devices face an array of stringent regional and international regulatory measures. They are in place to guarantee devices perform their desired function in a safe and efficient manner. Particulate matter makes up a crucial component of these regulations due to the potential harm they can cause to patients if left unchecked.
Manufacturers need to introduce thorough design, development and manufacturing procedures that minimise the presence of particulate matter on your components. Without it, having your device comfortably passing medical approval tests is impossible.
Factors like material composition, surface finish and specialised manufacturing processes need to be closely considered to minimise particulate matter. Alongside this, you need to manage the design and desired features of your device to strike a balance of compliance, performance and patient comfort. To achieve this balance, you need to have each of the aforementioned factors in mind from the very beginning of your design cycle.
In this article, we explore the importance of particulate matter for medical devices and the factors that influence their presence on specific components. You will learn the preventative design, development and manufacturing procedures that can minimise these concentrations and help your design pass through the approval process.
The importance of eliminating particulates: compliance matters.
Particulate matter is a prominent concern in the medical industry. This concern only grows with drug delivery devices due to the potential adverse health effects if they enter bloodstreams and respiratory systems. As a result, regional and international regulatory bodies have strict testing criteria for medical devices to manage the risk of particulate contamination in medical devices.
An example of requirements surrounding particulate matter is the FDA’s acceptance criteria of a minimum of 90% recovery for 10 - 25 µm particles and a minimum of 80% recovery for ≥25 µm particles. Additionally, these guidelines include the USP 788 requirements for particle count testing and verification. Simply put, you need to pay close attention to the particulate matter concentrations on your components in order for your design to pass regulatory trials.
The leading causes of particulates in medical manufacturing
One of the main factors that influence the presence of particulate matter on components is their tribology and surface friction. Friction is what traps particulate matter on the surface of components and is influenced by a number of variables.
- Material composition - Different materials showcase varying degrees of surface friction that influence particulate matter contamination.
- Surface finish - Similarly to material composition, surface finishes can be applied to components that affect its tribological properties.
- Manufacturing processes - The manufacturing processes involved in a component have a direct impact on the surface friction and particulate matter of the final device
Eliminating the risk of particulates is a question of design
Material composition
Selecting specific material compositions that minimise surface friction reduces the risk of particulate matter contaminations. In parallel to this, you also need to consider component performance and application to ensure the best overall choice of material for your design.
- Stainless Steel - Good resistance to wear whilst providing low surface friction.
- Carbon based - Particularly good for springs as it provides resistance to relaxation alongside low surface friction.
- Aluminium alloys - Good strength-to-weight ratio for lightweighting capabilities whilst minimising particulate matter.
Surface finish
In addition to reducing friction, surface finishes can provide surface properties that benefit specific applications by providing resistance to wear, corrosion and high temperatures.
A key process used in this respect is oiling. This provides a lubricative coating that aids components like springs in their operation and prolongs their lifespan. This coating also reduces surface roughness to minimise the concentration of particulate matter. Without oiling, components that require lubrication require a soap coating to prolong their lifespan. Unfortunately, this coating increases the susceptibility to particulate concentrations on the component’s surface.
Reducing particulates through better design
Deburring
Deburring is a manufacturing process that removes imperfections from a component’s surface that can appear from operations such as cutting. These imperfections are what result in surface roughness and particulate matter adhesion, highlighting the necessity of deburring for medical components.
- Vibratory - Using centrifugal, vibratory bowls with synthetic or ceramic media to smooth component imperfections. Vibratory deburring processes are highly efficient, allowing for large batches of components to maximise manufacturing productivity.
- Laser-deburring - Utilises a high-power laser beam to deburr component surfaces. This is used in cases where vibratory deburring is unsuitable for thin or fragile components as they can affect structural integrity.
Particulate removal
Near the end of the manufacture, medical components should be put through a particulate removal process. This can involve washing particulate matter from components using a solvent or aqueous solution. The components are immersed in a heated liquid media beforehand and are tumbled in media to help the cleaning process.
Ultrasonic cleaning is often carried out in conjunction with washing. An ultrasound generating transducer creates high frequency bubbles (20-400 kHz) to agitate media. This provides an additional stage of particulate removal that is particularly thorough.
Other forms of particulate removal processes include sieving and pickling. Sieving is the use of gentle abrasion against a gauze or mesh surface to dislodge particulates. Pickling describes the processes of submerging components in a citric or hydrochloric acid solution that removes the outer layer of the component that has embedded particulates.
Advanex Medical supports manufacturers expert support to eliminate particulates
Particulate matter is a crucial element of your pharmaceutical design that can easily prevent your device from passing through the approval process. You need to introduce design, development and manufacturing procedures from the initial stages of your components to minimise the presence of these particulates.
At Advanex Medical, we are your on-call partner for components, design and manufacture guidance to minimise the risk of particulates at every stage of your production. We have medical-grade facilities, specialised manufacturing processes and in-house medical expertise to support your design at every stage of its lifecycle. These are located globally to support manufacturers developing devices across every market.
To see how we can support you in developing a high-quality, easy-to-assemble medical device that goes to market seamlessly, get in touch with one of our experts.